Merge tag 'v3.12.74' into v3.12-rt
This is the 3.12.74 stable release
diff --git a/Documentation/hwlat_detector.txt b/Documentation/hwlat_detector.txt
new file mode 100644
index 0000000..cb61516
--- /dev/null
+++ b/Documentation/hwlat_detector.txt
@@ -0,0 +1,64 @@
+Introduction:
+-------------
+
+The module hwlat_detector is a special purpose kernel module that is used to
+detect large system latencies induced by the behavior of certain underlying
+hardware or firmware, independent of Linux itself. The code was developed
+originally to detect SMIs (System Management Interrupts) on x86 systems,
+however there is nothing x86 specific about this patchset. It was
+originally written for use by the "RT" patch since the Real Time
+kernel is highly latency sensitive.
+
+SMIs are usually not serviced by the Linux kernel, which typically does not
+even know that they are occuring. SMIs are instead are set up by BIOS code
+and are serviced by BIOS code, usually for "critical" events such as
+management of thermal sensors and fans. Sometimes though, SMIs are used for
+other tasks and those tasks can spend an inordinate amount of time in the
+handler (sometimes measured in milliseconds). Obviously this is a problem if
+you are trying to keep event service latencies down in the microsecond range.
+
+The hardware latency detector works by hogging all of the cpus for configurable
+amounts of time (by calling stop_machine()), polling the CPU Time Stamp Counter
+for some period, then looking for gaps in the TSC data. Any gap indicates a
+time when the polling was interrupted and since the machine is stopped and
+interrupts turned off the only thing that could do that would be an SMI.
+
+Note that the SMI detector should *NEVER* be used in a production environment.
+It is intended to be run manually to determine if the hardware platform has a
+problem with long system firmware service routines.
+
+Usage:
+------
+
+Loading the module hwlat_detector passing the parameter "enabled=1" (or by
+setting the "enable" entry in "hwlat_detector" debugfs toggled on) is the only
+step required to start the hwlat_detector. It is possible to redefine the
+threshold in microseconds (us) above which latency spikes will be taken
+into account (parameter "threshold=").
+
+Example:
+
+ # modprobe hwlat_detector enabled=1 threshold=100
+
+After the module is loaded, it creates a directory named "hwlat_detector" under
+the debugfs mountpoint, "/debug/hwlat_detector" for this text. It is necessary
+to have debugfs mounted, which might be on /sys/debug on your system.
+
+The /debug/hwlat_detector interface contains the following files:
+
+count - number of latency spikes observed since last reset
+enable - a global enable/disable toggle (0/1), resets count
+max - maximum hardware latency actually observed (usecs)
+sample - a pipe from which to read current raw sample data
+ in the format <timestamp> <latency observed usecs>
+ (can be opened O_NONBLOCK for a single sample)
+threshold - minimum latency value to be considered (usecs)
+width - time period to sample with CPUs held (usecs)
+ must be less than the total window size (enforced)
+window - total period of sampling, width being inside (usecs)
+
+By default we will set width to 500,000 and window to 1,000,000, meaning that
+we will sample every 1,000,000 usecs (1s) for 500,000 usecs (0.5s). If we
+observe any latencies that exceed the threshold (initially 100 usecs),
+then we write to a global sample ring buffer of 8K samples, which is
+consumed by reading from the "sample" (pipe) debugfs file interface.
diff --git a/Documentation/sysrq.txt b/Documentation/sysrq.txt
index 8cb4d78..d458683 100644
--- a/Documentation/sysrq.txt
+++ b/Documentation/sysrq.txt
@@ -57,10 +57,17 @@
On other - If you know of the key combos for other architectures, please
let me know so I can add them to this section.
-On all - write a character to /proc/sysrq-trigger. e.g.:
-
+On all - write a character to /proc/sysrq-trigger, e.g.:
echo t > /proc/sysrq-trigger
+On all - Enable network SysRq by writing a cookie to icmp_echo_sysrq, e.g.
+ echo 0x01020304 >/proc/sys/net/ipv4/icmp_echo_sysrq
+ Send an ICMP echo request with this pattern plus the particular
+ SysRq command key. Example:
+ # ping -c1 -s57 -p0102030468
+ will trigger the SysRq-H (help) command.
+
+
* What are the 'command' keys?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
'b' - Will immediately reboot the system without syncing or unmounting
diff --git a/Documentation/trace/histograms.txt b/Documentation/trace/histograms.txt
new file mode 100644
index 0000000..6f2aeab
--- /dev/null
+++ b/Documentation/trace/histograms.txt
@@ -0,0 +1,186 @@
+ Using the Linux Kernel Latency Histograms
+
+
+This document gives a short explanation how to enable, configure and use
+latency histograms. Latency histograms are primarily relevant in the
+context of real-time enabled kernels (CONFIG_PREEMPT/CONFIG_PREEMPT_RT)
+and are used in the quality management of the Linux real-time
+capabilities.
+
+
+* Purpose of latency histograms
+
+A latency histogram continuously accumulates the frequencies of latency
+data. There are two types of histograms
+- potential sources of latencies
+- effective latencies
+
+
+* Potential sources of latencies
+
+Potential sources of latencies are code segments where interrupts,
+preemption or both are disabled (aka critical sections). To create
+histograms of potential sources of latency, the kernel stores the time
+stamp at the start of a critical section, determines the time elapsed
+when the end of the section is reached, and increments the frequency
+counter of that latency value - irrespective of whether any concurrently
+running process is affected by latency or not.
+- Configuration items (in the Kernel hacking/Tracers submenu)
+ CONFIG_INTERRUPT_OFF_LATENCY
+ CONFIG_PREEMPT_OFF_LATENCY
+
+
+* Effective latencies
+
+Effective latencies are actually occuring during wakeup of a process. To
+determine effective latencies, the kernel stores the time stamp when a
+process is scheduled to be woken up, and determines the duration of the
+wakeup time shortly before control is passed over to this process. Note
+that the apparent latency in user space may be somewhat longer, since the
+process may be interrupted after control is passed over to it but before
+the execution in user space takes place. Simply measuring the interval
+between enqueuing and wakeup may also not appropriate in cases when a
+process is scheduled as a result of a timer expiration. The timer may have
+missed its deadline, e.g. due to disabled interrupts, but this latency
+would not be registered. Therefore, the offsets of missed timers are
+recorded in a separate histogram. If both wakeup latency and missed timer
+offsets are configured and enabled, a third histogram may be enabled that
+records the overall latency as a sum of the timer latency, if any, and the
+wakeup latency. This histogram is called "timerandwakeup".
+- Configuration items (in the Kernel hacking/Tracers submenu)
+ CONFIG_WAKEUP_LATENCY
+ CONFIG_MISSED_TIMER_OFSETS
+
+
+* Usage
+
+The interface to the administration of the latency histograms is located
+in the debugfs file system. To mount it, either enter
+
+mount -t sysfs nodev /sys
+mount -t debugfs nodev /sys/kernel/debug
+
+from shell command line level, or add
+
+nodev /sys sysfs defaults 0 0
+nodev /sys/kernel/debug debugfs defaults 0 0
+
+to the file /etc/fstab. All latency histogram related files are then
+available in the directory /sys/kernel/debug/tracing/latency_hist. A
+particular histogram type is enabled by writing non-zero to the related
+variable in the /sys/kernel/debug/tracing/latency_hist/enable directory.
+Select "preemptirqsoff" for the histograms of potential sources of
+latencies and "wakeup" for histograms of effective latencies etc. The
+histogram data - one per CPU - are available in the files
+
+/sys/kernel/debug/tracing/latency_hist/preemptoff/CPUx
+/sys/kernel/debug/tracing/latency_hist/irqsoff/CPUx
+/sys/kernel/debug/tracing/latency_hist/preemptirqsoff/CPUx
+/sys/kernel/debug/tracing/latency_hist/wakeup/CPUx
+/sys/kernel/debug/tracing/latency_hist/wakeup/sharedprio/CPUx
+/sys/kernel/debug/tracing/latency_hist/missed_timer_offsets/CPUx
+/sys/kernel/debug/tracing/latency_hist/timerandwakeup/CPUx
+
+The histograms are reset by writing non-zero to the file "reset" in a
+particular latency directory. To reset all latency data, use
+
+#!/bin/sh
+
+TRACINGDIR=/sys/kernel/debug/tracing
+HISTDIR=$TRACINGDIR/latency_hist
+
+if test -d $HISTDIR
+then
+ cd $HISTDIR
+ for i in `find . | grep /reset$`
+ do
+ echo 1 >$i
+ done
+fi
+
+
+* Data format
+
+Latency data are stored with a resolution of one microsecond. The
+maximum latency is 10,240 microseconds. The data are only valid, if the
+overflow register is empty. Every output line contains the latency in
+microseconds in the first row and the number of samples in the second
+row. To display only lines with a positive latency count, use, for
+example,
+
+grep -v " 0$" /sys/kernel/debug/tracing/latency_hist/preemptoff/CPU0
+
+#Minimum latency: 0 microseconds.
+#Average latency: 0 microseconds.
+#Maximum latency: 25 microseconds.
+#Total samples: 3104770694
+#There are 0 samples greater or equal than 10240 microseconds
+#usecs samples
+ 0 2984486876
+ 1 49843506
+ 2 58219047
+ 3 5348126
+ 4 2187960
+ 5 3388262
+ 6 959289
+ 7 208294
+ 8 40420
+ 9 4485
+ 10 14918
+ 11 18340
+ 12 25052
+ 13 19455
+ 14 5602
+ 15 969
+ 16 47
+ 17 18
+ 18 14
+ 19 1
+ 20 3
+ 21 2
+ 22 5
+ 23 2
+ 25 1
+
+
+* Wakeup latency of a selected process
+
+To only collect wakeup latency data of a particular process, write the
+PID of the requested process to
+
+/sys/kernel/debug/tracing/latency_hist/wakeup/pid
+
+PIDs are not considered, if this variable is set to 0.
+
+
+* Details of the process with the highest wakeup latency so far
+
+Selected data of the process that suffered from the highest wakeup
+latency that occurred in a particular CPU are available in the file
+
+/sys/kernel/debug/tracing/latency_hist/wakeup/max_latency-CPUx.
+
+In addition, other relevant system data at the time when the
+latency occurred are given.
+
+The format of the data is (all in one line):
+<PID> <Priority> <Latency> (<Timeroffset>) <Command> \
+<- <PID> <Priority> <Command> <Timestamp>
+
+The value of <Timeroffset> is only relevant in the combined timer
+and wakeup latency recording. In the wakeup recording, it is
+always 0, in the missed_timer_offsets recording, it is the same
+as <Latency>.
+
+When retrospectively searching for the origin of a latency and
+tracing was not enabled, it may be helpful to know the name and
+some basic data of the task that (finally) was switching to the
+late real-tlme task. In addition to the victim's data, also the
+data of the possible culprit are therefore displayed after the
+"<-" symbol.
+
+Finally, the timestamp of the time when the latency occurred
+in <seconds>.<microseconds> after the most recent system boot
+is provided.
+
+These data are also reset when the wakeup histogram is reset.
diff --git a/Makefile b/Makefile
index 28b1d91..ec0a550 100644
--- a/Makefile
+++ b/Makefile
@@ -376,7 +376,7 @@
KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -fno-common \
-Werror-implicit-function-declaration \
- -Wno-format-security \
+ -Wno-format-security -fno-PIE \
-fno-delete-null-pointer-checks \
-std=gnu89 $(call cc-option,-fno-PIE)
diff --git a/arch/Kconfig b/arch/Kconfig
index af2cc6e..b1a3995 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -6,6 +6,7 @@
tristate "OProfile system profiling"
depends on PROFILING
depends on HAVE_OPROFILE
+ depends on !PREEMPT_RT_FULL
select RING_BUFFER
select RING_BUFFER_ALLOW_SWAP
help
@@ -49,6 +50,7 @@
config JUMP_LABEL
bool "Optimize very unlikely/likely branches"
depends on HAVE_ARCH_JUMP_LABEL
+ depends on (!INTERRUPT_OFF_HIST && !PREEMPT_OFF_HIST && !WAKEUP_LATENCY_HIST && !MISSED_TIMER_OFFSETS_HIST)
help
This option enables a transparent branch optimization that
makes certain almost-always-true or almost-always-false branch
diff --git a/arch/alpha/include/asm/Kbuild b/arch/alpha/include/asm/Kbuild
index a6e85f44..38c9399 100644
--- a/arch/alpha/include/asm/Kbuild
+++ b/arch/alpha/include/asm/Kbuild
@@ -3,3 +3,4 @@
generic-y += exec.h
generic-y += trace_clock.h
+generic-y += irq_work.h
diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c
index 9d0ac09..870f626 100644
--- a/arch/alpha/mm/fault.c
+++ b/arch/alpha/mm/fault.c
@@ -107,7 +107,7 @@
/* If we're in an interrupt context, or have no user context,
we must not take the fault. */
- if (!mm || in_atomic())
+ if (!mm || pagefault_disabled())
goto no_context;
#ifdef CONFIG_ALPHA_LARGE_VMALLOC
diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild
index 5c359cf..51a086e 100644
--- a/arch/arc/include/asm/Kbuild
+++ b/arch/arc/include/asm/Kbuild
@@ -16,6 +16,7 @@
generic-y += ioctls.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kmap_types.h
generic-y += kvm_para.h
generic-y += local.h
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 99e1ce97..ad101e4 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -52,6 +52,7 @@
select HAVE_MOD_ARCH_SPECIFIC if ARM_UNWIND
select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
select HAVE_PERF_EVENTS
+ select HAVE_PREEMPT_LAZY
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UID16
diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild
index 59ceae8..5b9f62c 100644
--- a/arch/arm/include/asm/Kbuild
+++ b/arch/arm/include/asm/Kbuild
@@ -10,6 +10,7 @@
generic-y += ioctl.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kdebug.h
generic-y += local.h
generic-y += local64.h
diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h
index 4f009c1..a86b680 100644
--- a/arch/arm/include/asm/cmpxchg.h
+++ b/arch/arm/include/asm/cmpxchg.h
@@ -127,6 +127,8 @@
#else /* min ARCH >= ARMv6 */
+#define __HAVE_ARCH_CMPXCHG 1
+
extern void __bad_cmpxchg(volatile void *ptr, int size);
/*
diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h
index 2aff798..54d26a9 100644
--- a/arch/arm/include/asm/futex.h
+++ b/arch/arm/include/asm/futex.h
@@ -90,6 +90,8 @@
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
+ preempt_disable_rt();
+
__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
"1: " TUSER(ldr) " %1, [%4]\n"
" teq %1, %2\n"
@@ -101,6 +103,8 @@
: "cc", "memory");
*uval = val;
+
+ preempt_enable_rt();
return ret;
}
diff --git a/arch/arm/include/asm/switch_to.h b/arch/arm/include/asm/switch_to.h
index c99e259..f3e3d80 100644
--- a/arch/arm/include/asm/switch_to.h
+++ b/arch/arm/include/asm/switch_to.h
@@ -3,6 +3,13 @@
#include <linux/thread_info.h>
+#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM
+void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p);
+#else
+static inline void
+switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { }
+#endif
+
/*
* For v7 SMP cores running a preemptible kernel we may be pre-empted
* during a TLB maintenance operation, so execute an inner-shareable dsb
@@ -22,6 +29,7 @@
#define switch_to(prev,next,last) \
do { \
+ switch_kmaps(prev, next); \
last = __switch_to(prev,task_thread_info(prev), task_thread_info(next)); \
} while (0)
diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index 2b8114f..cef6be7 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -50,6 +50,7 @@
struct thread_info {
unsigned long flags; /* low level flags */
int preempt_count; /* 0 => preemptable, <0 => bug */
+ int preempt_lazy_count; /* 0 => preemptable, <0 => bug */
mm_segment_t addr_limit; /* address limit */
struct task_struct *task; /* main task structure */
struct exec_domain *exec_domain; /* execution domain */
@@ -148,6 +149,7 @@
#define TIF_SIGPENDING 0
#define TIF_NEED_RESCHED 1
#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
+#define TIF_NEED_RESCHED_LAZY 3
#define TIF_SYSCALL_TRACE 8
#define TIF_SYSCALL_AUDIT 9
#define TIF_SYSCALL_TRACEPOINT 10
@@ -160,6 +162,7 @@
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
+#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY)
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index 85598b5..e9f119e 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -54,6 +54,7 @@
BLANK();
DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
+ DEFINE(TI_PREEMPT_LAZY, offsetof(struct thread_info, preempt_lazy_count));
DEFINE(TI_ADDR_LIMIT, offsetof(struct thread_info, addr_limit));
DEFINE(TI_TASK, offsetof(struct thread_info, task));
DEFINE(TI_EXEC_DOMAIN, offsetof(struct thread_info, exec_domain));
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index ec3e5cf..96eb4d2 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -205,11 +205,18 @@
#ifdef CONFIG_PREEMPT
get_thread_info tsk
ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
- ldr r0, [tsk, #TI_FLAGS] @ get flags
teq r8, #0 @ if preempt count != 0
+ bne 1f @ return from exeption
+ ldr r0, [tsk, #TI_FLAGS] @ get flags
+ tst r0, #_TIF_NEED_RESCHED @ if NEED_RESCHED is set
+ blne svc_preempt @ preempt!
+
+ ldr r8, [tsk, #TI_PREEMPT_LAZY] @ get preempt lazy count
+ teq r8, #0 @ if preempt lazy count != 0
movne r0, #0 @ force flags to 0
- tst r0, #_TIF_NEED_RESCHED
+ tst r0, #_TIF_NEED_RESCHED_LAZY
blne svc_preempt
+1:
#endif
svc_exit r5, irq = 1 @ return from exception
@@ -224,8 +231,14 @@
1: bl preempt_schedule_irq @ irq en/disable is done inside
ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS
tst r0, #_TIF_NEED_RESCHED
+ bne 1b
+ tst r0, #_TIF_NEED_RESCHED_LAZY
moveq pc, r8 @ go again
- b 1b
+ ldr r0, [tsk, #TI_PREEMPT_LAZY] @ get preempt lazy count
+ teq r0, #0 @ if preempt lazy count != 0
+ beq 1b
+ mov pc, r8 @ go again
+
#endif
__und_fault:
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 5f6e650..e35007d 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -434,6 +434,30 @@
}
#ifdef CONFIG_MMU
+/*
+ * CONFIG_SPLIT_PTLOCK_CPUS results in a page->ptl lock. If the lock is not
+ * initialized by pgtable_page_ctor() then a coredump of the vector page will
+ * fail.
+ */
+static int __init vectors_user_mapping_init_page(void)
+{
+ struct page *page;
+ unsigned long addr = 0xffff0000;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ pgd = pgd_offset_k(addr);
+ pud = pud_offset(pgd, addr);
+ pmd = pmd_offset(pud, addr);
+ page = pmd_page(*(pmd));
+
+ pgtable_page_ctor(page);
+
+ return 0;
+}
+late_initcall(vectors_user_mapping_init_page);
+
#ifdef CONFIG_KUSER_HELPERS
/*
* The vectors page is always readable from user space for the
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index ab5b238..ddaf09f 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -600,7 +600,8 @@
do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
{
do {
- if (likely(thread_flags & _TIF_NEED_RESCHED)) {
+ if (likely(thread_flags & (_TIF_NEED_RESCHED |
+ _TIF_NEED_RESCHED_LAZY))) {
schedule();
} else {
if (unlikely(!user_mode(regs)))
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index bd1b9e6..2f73259 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -207,8 +207,6 @@
flush_cache_louis();
local_flush_tlb_all();
- clear_tasks_mm_cpumask(cpu);
-
return 0;
}
@@ -224,6 +222,9 @@
pr_err("CPU%u: cpu didn't die\n", cpu);
return;
}
+
+ clear_tasks_mm_cpumask(cpu);
+
printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
/*
diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c
index 00df012..bbafc67 100644
--- a/arch/arm/kernel/unwind.c
+++ b/arch/arm/kernel/unwind.c
@@ -87,7 +87,7 @@
static const struct unwind_idx *__origin_unwind_idx;
extern const struct unwind_idx __stop_unwind_idx[];
-static DEFINE_SPINLOCK(unwind_lock);
+static DEFINE_RAW_SPINLOCK(unwind_lock);
static LIST_HEAD(unwind_tables);
/* Convert a prel31 symbol to an absolute address */
@@ -195,7 +195,7 @@
/* module unwind tables */
struct unwind_table *table;
- spin_lock_irqsave(&unwind_lock, flags);
+ raw_spin_lock_irqsave(&unwind_lock, flags);
list_for_each_entry(table, &unwind_tables, list) {
if (addr >= table->begin_addr &&
addr < table->end_addr) {
@@ -207,7 +207,7 @@
break;
}
}
- spin_unlock_irqrestore(&unwind_lock, flags);
+ raw_spin_unlock_irqrestore(&unwind_lock, flags);
}
pr_debug("%s: idx = %p\n", __func__, idx);
@@ -469,9 +469,9 @@
tab->begin_addr = text_addr;
tab->end_addr = text_addr + text_size;
- spin_lock_irqsave(&unwind_lock, flags);
+ raw_spin_lock_irqsave(&unwind_lock, flags);
list_add_tail(&tab->list, &unwind_tables);
- spin_unlock_irqrestore(&unwind_lock, flags);
+ raw_spin_unlock_irqrestore(&unwind_lock, flags);
return tab;
}
@@ -483,9 +483,9 @@
if (!tab)
return;
- spin_lock_irqsave(&unwind_lock, flags);
+ raw_spin_lock_irqsave(&unwind_lock, flags);
list_del(&tab->list);
- spin_unlock_irqrestore(&unwind_lock, flags);
+ raw_spin_unlock_irqrestore(&unwind_lock, flags);
kfree(tab);
}
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 25e58d3..5d8c1ef 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -468,9 +468,9 @@
static void vcpu_pause(struct kvm_vcpu *vcpu)
{
- wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
+ struct swait_head *wq = kvm_arch_vcpu_wq(vcpu);
- wait_event_interruptible(*wq, !vcpu->arch.pause);
+ swait_event_interruptible(*wq, !vcpu->arch.pause);
}
static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 485387b..abb3b0b 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -36,7 +36,7 @@
{
struct kvm *kvm = source_vcpu->kvm;
struct kvm_vcpu *vcpu = NULL, *tmp;
- wait_queue_head_t *wq;
+ struct swait_head *wq;
unsigned long cpu_id;
unsigned long mpidr;
phys_addr_t target_pc;
@@ -77,7 +77,7 @@
smp_mb(); /* Make sure the above is visible */
wq = kvm_arch_vcpu_wq(vcpu);
- wake_up_interruptible(wq);
+ swait_wake_interruptible(wq);
return KVM_PSCI_RET_SUCCESS;
}
diff --git a/arch/arm/mach-at91/at91rm9200_time.c b/arch/arm/mach-at91/at91rm9200_time.c
index f607deb..35f7b26 100644
--- a/arch/arm/mach-at91/at91rm9200_time.c
+++ b/arch/arm/mach-at91/at91rm9200_time.c
@@ -134,6 +134,7 @@
break;
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
+ remove_irq(NR_IRQS_LEGACY + AT91_ID_SYS, &at91rm9200_timer_irq);
case CLOCK_EVT_MODE_RESUME:
irqmask = 0;
break;
diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c
index bb39232..1c4c487 100644
--- a/arch/arm/mach-at91/at91sam926x_time.c
+++ b/arch/arm/mach-at91/at91sam926x_time.c
@@ -77,7 +77,7 @@
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
-
+static struct irqaction at91sam926x_pit_irq;
/*
* Clockevent device: interrupts every 1/HZ (== pit_cycles * MCK/16)
*/
@@ -86,6 +86,8 @@
{
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
+ /* Set up irq handler */
+ setup_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
/* update clocksource counter */
pit_cnt += pit_cycle * PIT_PICNT(pit_read(AT91_PIT_PIVR));
pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN
@@ -98,6 +100,7 @@
case CLOCK_EVT_MODE_UNUSED:
/* disable irq, leaving the clocksource active */
pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN);
+ remove_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
break;
case CLOCK_EVT_MODE_RESUME:
break;
diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
index 58b43e6..f56f767 100644
--- a/arch/arm/mach-exynos/platsmp.c
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -73,7 +73,7 @@
return (void __iomem *)(S5P_VA_SCU);
}
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
static void exynos_secondary_init(unsigned int cpu)
{
@@ -86,8 +86,8 @@
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -99,7 +99,7 @@
* Set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -128,7 +128,7 @@
if (timeout == 0) {
printk(KERN_ERR "cpu1 power enable failed");
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return -ETIMEDOUT;
}
}
@@ -167,7 +167,7 @@
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mach-msm/platsmp.c b/arch/arm/mach-msm/platsmp.c
index 3f06edc..fc09a04 100644
--- a/arch/arm/mach-msm/platsmp.c
+++ b/arch/arm/mach-msm/platsmp.c
@@ -30,7 +30,7 @@
extern void msm_secondary_startup(void);
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
static inline int get_core_count(void)
{
@@ -50,8 +50,8 @@
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static void prepare_cold_cpu(unsigned int cpu)
@@ -88,7 +88,7 @@
* set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -122,7 +122,7 @@
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
index 8912110..5969da3 100644
--- a/arch/arm/mach-omap2/omap-smp.c
+++ b/arch/arm/mach-omap2/omap-smp.c
@@ -44,7 +44,7 @@
/* SCU base address */
static void __iomem *scu_base;
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
void __iomem *omap4_get_scu_base(void)
{
@@ -68,8 +68,8 @@
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -83,7 +83,7 @@
* Set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* Update the AuxCoreBoot0 with boot state for secondary core.
@@ -160,7 +160,7 @@
* Now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return 0;
}
diff --git a/arch/arm/mach-prima2/platsmp.c b/arch/arm/mach-prima2/platsmp.c
index 3dbcb1a..42837dc4 100644
--- a/arch/arm/mach-prima2/platsmp.c
+++ b/arch/arm/mach-prima2/platsmp.c
@@ -23,7 +23,7 @@
static void __iomem *scu_base;
static void __iomem *rsc_base;
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
static struct map_desc scu_io_desc __initdata = {
.length = SZ_4K,
@@ -56,8 +56,8 @@
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static struct of_device_id rsc_ids[] = {
@@ -95,7 +95,7 @@
/* make sure write buffer is drained */
mb();
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -128,7 +128,7 @@
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mach-spear/platsmp.c b/arch/arm/mach-spear/platsmp.c
index 5c4a198..33dc270 100644
--- a/arch/arm/mach-spear/platsmp.c
+++ b/arch/arm/mach-spear/platsmp.c
@@ -20,7 +20,7 @@
#include <mach/spear.h>
#include "generic.h"
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
static void __iomem *scu_base = IOMEM(VA_SCU_BASE);
@@ -36,8 +36,8 @@
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -48,7 +48,7 @@
* set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -75,7 +75,7 @@
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mach-sti/platsmp.c b/arch/arm/mach-sti/platsmp.c
index dce50d9..c05b764 100644
--- a/arch/arm/mach-sti/platsmp.c
+++ b/arch/arm/mach-sti/platsmp.c
@@ -35,7 +35,7 @@
outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
}
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
void sti_secondary_init(unsigned int cpu)
{
@@ -50,8 +50,8 @@
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
int sti_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -62,7 +62,7 @@
* set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -93,7 +93,7 @@
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mach-ux500/platsmp.c b/arch/arm/mach-ux500/platsmp.c
index 1f296e7..eeb5916 100644
--- a/arch/arm/mach-ux500/platsmp.c
+++ b/arch/arm/mach-ux500/platsmp.c
@@ -52,7 +52,7 @@
return NULL;
}
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
static void ux500_secondary_init(unsigned int cpu)
{
@@ -65,8 +65,8 @@
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -77,7 +77,7 @@
* set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
@@ -98,7 +98,7 @@
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index eb8830a..c15d2a0 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -277,7 +277,7 @@
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
if (user_mode(regs))
@@ -431,6 +431,9 @@
if (addr < TASK_SIZE)
return do_page_fault(addr, fsr, regs);
+ if (interrupts_enabled(regs))
+ local_irq_enable();
+
if (user_mode(regs))
goto bad_area;
@@ -498,6 +501,9 @@
static int
do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{
+ if (interrupts_enabled(regs))
+ local_irq_enable();
+
do_bad_area(addr, fsr, regs);
return 0;
}
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index 21b9e1b..bd41dd8 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -38,6 +38,7 @@
void *kmap_atomic(struct page *page)
{
+ pte_t pte = mk_pte(page, kmap_prot);
unsigned int idx;
unsigned long vaddr;
void *kmap;
@@ -76,7 +77,10 @@
* in place, so the contained TLB flush ensures the TLB is updated
* with the new mapping.
*/
- set_top_pte(vaddr, mk_pte(page, kmap_prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = pte;
+#endif
+ set_top_pte(vaddr, pte);
return (void *)vaddr;
}
@@ -93,12 +97,15 @@
if (cache_is_vivt())
__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = __pte(0);
+#endif
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
- set_top_pte(vaddr, __pte(0));
#else
(void) idx; /* to kill a warning */
#endif
+ set_top_pte(vaddr, __pte(0));
kmap_atomic_idx_pop();
} else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
/* this address was obtained through kmap_high_get() */
@@ -110,6 +117,7 @@
void *kmap_atomic_pfn(unsigned long pfn)
{
+ pte_t pte = pfn_pte(pfn, kmap_prot);
unsigned long vaddr;
int idx, type;
@@ -121,7 +129,10 @@
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(get_top_pte(vaddr)));
#endif
- set_top_pte(vaddr, pfn_pte(pfn, kmap_prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = pte;
+#endif
+ set_top_pte(vaddr, pte);
return (void *)vaddr;
}
@@ -135,3 +146,29 @@
return pte_page(get_top_pte(vaddr));
}
+
+#if defined CONFIG_PREEMPT_RT_FULL
+void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p)
+{
+ int i;
+
+ /*
+ * Clear @prev's kmap_atomic mappings
+ */
+ for (i = 0; i < prev_p->kmap_idx; i++) {
+ int idx = i + KM_TYPE_NR * smp_processor_id();
+
+ set_top_pte(__fix_to_virt(FIX_KMAP_BEGIN + idx), __pte(0));
+ }
+ /*
+ * Restore @next_p's kmap_atomic mappings
+ */
+ for (i = 0; i < next_p->kmap_idx; i++) {
+ int idx = i + KM_TYPE_NR * smp_processor_id();
+
+ if (!pte_none(next_p->kmap_pte[i]))
+ set_top_pte(__fix_to_virt(FIX_KMAP_BEGIN + idx),
+ next_p->kmap_pte[i]);
+ }
+}
+#endif
diff --git a/arch/arm/plat-versatile/platsmp.c b/arch/arm/plat-versatile/platsmp.c
index 39895d8..b2e0858 100644
--- a/arch/arm/plat-versatile/platsmp.c
+++ b/arch/arm/plat-versatile/platsmp.c
@@ -31,7 +31,7 @@
outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
}
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
void versatile_secondary_init(unsigned int cpu)
{
@@ -44,8 +44,8 @@
/*
* Synchronise with the boot thread.
*/
- spin_lock(&boot_lock);
- spin_unlock(&boot_lock);
+ raw_spin_lock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
}
int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -56,7 +56,7 @@
* Set synchronisation state between this boot processor
* and the secondary one
*/
- spin_lock(&boot_lock);
+ raw_spin_lock(&boot_lock);
/*
* This is really belt and braces; we hold unintended secondary
@@ -86,7 +86,7 @@
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
- spin_unlock(&boot_lock);
+ raw_spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild
index 79a642d..1ba96d7 100644
--- a/arch/arm64/include/asm/Kbuild
+++ b/arch/arm64/include/asm/Kbuild
@@ -17,6 +17,7 @@
generic-y += ioctls.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += kvm_para.h
diff --git a/arch/avr32/include/asm/Kbuild b/arch/avr32/include/asm/Kbuild
index fd79807..383de8a 100644
--- a/arch/avr32/include/asm/Kbuild
+++ b/arch/avr32/include/asm/Kbuild
@@ -8,6 +8,7 @@
generic-y += exec.h
generic-y += futex.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += param.h
generic-y += local.h
generic-y += local64.h
diff --git a/arch/avr32/mm/fault.c b/arch/avr32/mm/fault.c
index d223a8b..8a7fb93 100644
--- a/arch/avr32/mm/fault.c
+++ b/arch/avr32/mm/fault.c
@@ -81,7 +81,7 @@
* If we're in an interrupt or have no user context, we must
* not take the fault...
*/
- if (in_atomic() || !mm || regs->sr & SYSREG_BIT(GM))
+ if (!mm || regs->sr & SYSREG_BIT(GM) || pagefault_disabled())
goto no_context;
local_irq_enable();
diff --git a/arch/blackfin/include/asm/Kbuild b/arch/blackfin/include/asm/Kbuild
index 127826f..f3d203c 100644
--- a/arch/blackfin/include/asm/Kbuild
+++ b/arch/blackfin/include/asm/Kbuild
@@ -14,6 +14,7 @@
generic-y += ioctl.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += kvm_para.h
diff --git a/arch/c6x/include/asm/Kbuild b/arch/c6x/include/asm/Kbuild
index e49f918..920d346 100644
--- a/arch/c6x/include/asm/Kbuild
+++ b/arch/c6x/include/asm/Kbuild
@@ -21,6 +21,7 @@
generic-y += ioctls.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += local.h
diff --git a/arch/cris/include/asm/Kbuild b/arch/cris/include/asm/Kbuild
index 874f77c..8291eef 100644
--- a/arch/cris/include/asm/Kbuild
+++ b/arch/cris/include/asm/Kbuild
@@ -5,6 +5,7 @@
generic-y += linkage.h
generic-y += module.h
generic-y += trace_clock.h
+generic-y += irq_work.h
generic-y += vga.h
generic-y += xor.h
generic-y += barrier.h
diff --git a/arch/cris/mm/fault.c b/arch/cris/mm/fault.c
index 2686a7a..b1a5631 100644
--- a/arch/cris/mm/fault.c
+++ b/arch/cris/mm/fault.c
@@ -113,7 +113,7 @@
* user context, we must not take the fault.
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
if (user_mode(regs))
diff --git a/arch/frv/include/asm/Kbuild b/arch/frv/include/asm/Kbuild
index c5d7670..a607aa4 100644
--- a/arch/frv/include/asm/Kbuild
+++ b/arch/frv/include/asm/Kbuild
@@ -2,3 +2,4 @@
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
+generic-y += irq_work.h
diff --git a/arch/frv/mm/fault.c b/arch/frv/mm/fault.c
index ec4917d..c90d23f5 100644
--- a/arch/frv/mm/fault.c
+++ b/arch/frv/mm/fault.c
@@ -78,7 +78,7 @@
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
if (user_mode(__frame))
diff --git a/arch/hexagon/include/asm/Kbuild b/arch/hexagon/include/asm/Kbuild
index a214fa4..15ee577 100644
--- a/arch/hexagon/include/asm/Kbuild
+++ b/arch/hexagon/include/asm/Kbuild
@@ -21,6 +21,7 @@
generic-y += iomap.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += local64.h
diff --git a/arch/ia64/include/asm/Kbuild b/arch/ia64/include/asm/Kbuild
index a3456f3..85b48f4 100644
--- a/arch/ia64/include/asm/Kbuild
+++ b/arch/ia64/include/asm/Kbuild
@@ -3,4 +3,5 @@
generic-y += exec.h
generic-y += kvm_para.h
generic-y += trace_clock.h
-generic-y += vtime.h
\ No newline at end of file
+generic-y += irq_work.h
+generic-y += vtime.h
diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index ba5ba7a..f9f7d083 100644
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -96,7 +96,7 @@
/*
* If we're in an interrupt or have no user context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
#ifdef CONFIG_VIRTUAL_MEM_MAP
diff --git a/arch/m32r/include/asm/Kbuild b/arch/m32r/include/asm/Kbuild
index bebdc36..7b17547 100644
--- a/arch/m32r/include/asm/Kbuild
+++ b/arch/m32r/include/asm/Kbuild
@@ -3,3 +3,4 @@
generic-y += exec.h
generic-y += module.h
generic-y += trace_clock.h
+generic-y += irq_work.h
diff --git a/arch/m32r/mm/fault.c b/arch/m32r/mm/fault.c
index e3d4d48901..7069ad3 100644
--- a/arch/m32r/mm/fault.c
+++ b/arch/m32r/mm/fault.c
@@ -114,7 +114,7 @@
* If we're in an interrupt or have no user context or are running in an
* atomic region then we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto bad_area_nosemaphore;
if (error_code & ACE_USERMODE)
diff --git a/arch/m68k/include/asm/Kbuild b/arch/m68k/include/asm/Kbuild
index 09d77a8..39e4ed9 100644
--- a/arch/m68k/include/asm/Kbuild
+++ b/arch/m68k/include/asm/Kbuild
@@ -10,6 +10,7 @@
generic-y += ioctl.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += kvm_para.h
diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c
index 97136b5..9665254 100644
--- a/arch/m68k/mm/fault.c
+++ b/arch/m68k/mm/fault.c
@@ -84,7 +84,7 @@
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
if (user_mode(regs))
diff --git a/arch/metag/include/asm/Kbuild b/arch/metag/include/asm/Kbuild
index 6ae0ccb..b9c4250 100644
--- a/arch/metag/include/asm/Kbuild
+++ b/arch/metag/include/asm/Kbuild
@@ -18,6 +18,7 @@
generic-y += ioctls.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += kvm_para.h
diff --git a/arch/microblaze/include/asm/Kbuild b/arch/microblaze/include/asm/Kbuild
index 9197b37..b45a73d 100644
--- a/arch/microblaze/include/asm/Kbuild
+++ b/arch/microblaze/include/asm/Kbuild
@@ -2,5 +2,6 @@
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
+generic-y += irq_work.h
generic-y += syscalls.h
generic-y += barrier.h
diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c
index d46a5eb..914ae86 100644
--- a/arch/microblaze/mm/fault.c
+++ b/arch/microblaze/mm/fault.c
@@ -107,7 +107,7 @@
if ((error_code & 0x13) == 0x13 || (error_code & 0x11) == 0x11)
is_write = 0;
- if (unlikely(in_atomic() || !mm)) {
+ if (unlikely(!mm || pagefault_disabled())) {
if (kernel_mode(regs))
goto bad_area_nosemaphore;
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index f75ab4a..f3981c2 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2078,7 +2078,7 @@
#
config HIGHMEM
bool "High Memory Support"
- depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM
+ depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM && !PREEMPT_RT_FULL
config CPU_SUPPORTS_HIGHMEM
bool
diff --git a/arch/mips/include/asm/Kbuild b/arch/mips/include/asm/Kbuild
index 454ddf9..a058bb0 100644
--- a/arch/mips/include/asm/Kbuild
+++ b/arch/mips/include/asm/Kbuild
@@ -11,5 +11,6 @@
generic-y += segment.h
generic-y += serial.h
generic-y += trace_clock.h
+generic-y += irq_work.h
generic-y += ucontext.h
generic-y += xor.h
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 2f285ab..a4ae7ad 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -573,6 +573,7 @@
__u32 thread_info_flags)
{
local_irq_enable();
+ preempt_check_resched();
user_exit();
diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index 70ab5d6..5b41b84 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -89,7 +89,7 @@
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto bad_area_nosemaphore;
if (user_mode(regs))
diff --git a/arch/mn10300/include/asm/Kbuild b/arch/mn10300/include/asm/Kbuild
index a530bca..fe2a2e3 100644
--- a/arch/mn10300/include/asm/Kbuild
+++ b/arch/mn10300/include/asm/Kbuild
@@ -3,3 +3,4 @@
generic-y += exec.h
generic-y += trace_clock.h
generic-y += barrier.h
+generic-y += irq_work.h
diff --git a/arch/mn10300/mm/fault.c b/arch/mn10300/mm/fault.c
index 0c2cc5d..54305d2 100644
--- a/arch/mn10300/mm/fault.c
+++ b/arch/mn10300/mm/fault.c
@@ -168,7 +168,7 @@
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR)
diff --git a/arch/openrisc/include/asm/Kbuild b/arch/openrisc/include/asm/Kbuild
index 195653e..9ff5f42 100644
--- a/arch/openrisc/include/asm/Kbuild
+++ b/arch/openrisc/include/asm/Kbuild
@@ -30,6 +30,7 @@
generic-y += ioctls.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += kvm_para.h
diff --git a/arch/parisc/include/asm/Kbuild b/arch/parisc/include/asm/Kbuild
index 827a846..c492762 100644
--- a/arch/parisc/include/asm/Kbuild
+++ b/arch/parisc/include/asm/Kbuild
@@ -5,3 +5,4 @@
poll.h xor.h clkdev.h exec.h
generic-y += trace_clock.h
generic-y += barrier.h
+generic-y += irq_work.h
diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c
index 0dda59c..4a8aec2 100644
--- a/arch/parisc/mm/fault.c
+++ b/arch/parisc/mm/fault.c
@@ -177,7 +177,7 @@
int fault;
unsigned int flags;
- if (in_atomic())
+ if (pagefault_disabled())
goto no_context;
tsk = current;
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 2e0ddfa..9b33a0f 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -60,10 +60,11 @@
config RWSEM_GENERIC_SPINLOCK
bool
+ default y if PREEMPT_RT_FULL
config RWSEM_XCHGADD_ALGORITHM
bool
- default y
+ default y if !PREEMPT_RT_FULL
config GENERIC_LOCKBREAK
bool
@@ -131,6 +132,7 @@
select GENERIC_CLOCKEVENTS
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
+ select HAVE_PREEMPT_LAZY
select HAVE_MOD_ARCH_SPECIFIC
select MODULES_USE_ELF_RELA
select CLONE_BACKWARDS
@@ -286,7 +288,7 @@
config HIGHMEM
bool "High memory support"
- depends on PPC32
+ depends on PPC32 && !PREEMPT_RT_FULL
source kernel/Kconfig.hz
source kernel/Kconfig.preempt
diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
index 704e6f1..9616664 100644
--- a/arch/powerpc/include/asm/Kbuild
+++ b/arch/powerpc/include/asm/Kbuild
@@ -2,4 +2,5 @@
generic-y += clkdev.h
generic-y += rwsem.h
generic-y += trace_clock.h
-generic-y += vtime.h
\ No newline at end of file
+generic-y += irq_work.h
+generic-y += vtime.h
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 3328353..5fa50fc 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -290,7 +290,7 @@
u8 in_guest;
struct list_head runnable_threads;
spinlock_t lock;
- wait_queue_head_t wq;
+ struct swait_head wq;
u64 stolen_tb;
u64 preempt_tb;
struct kvm_vcpu *runner;
@@ -562,7 +562,7 @@
u8 prodded;
u32 last_inst;
- wait_queue_head_t *wqp;
+ struct swait_head *wqp;
struct kvmppc_vcore *vcore;
int ret;
int trap;
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index ba7b197..f50711f 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -43,6 +43,8 @@
int cpu; /* cpu we're on */
int preempt_count; /* 0 => preemptable,
<0 => BUG */
+ int preempt_lazy_count; /* 0 => preemptable,
+ <0 => BUG */
struct restart_block restart_block;
unsigned long local_flags; /* private flags for thread */
@@ -90,8 +92,7 @@
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_SIGPENDING 1 /* signal pending */
#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
-#define TIF_POLLING_NRFLAG 3 /* true if poll_idle() is polling
- TIF_NEED_RESCHED */
+#define TIF_NEED_RESCHED_LAZY 3 /* lazy rescheduling necessary */
#define TIF_32BIT 4 /* 32 bit binary */
#define TIF_PERFMON_WORK 5 /* work for pfm_handle_work() */
#define TIF_PERFMON_CTXSW 6 /* perfmon needs ctxsw calls */
@@ -107,6 +108,8 @@
#define TIF_EMULATE_STACK_STORE 16 /* Is an instruction emulation
for stack store? */
#define TIF_MEMDIE 17 /* is terminating due to OOM killer */
+#define TIF_POLLING_NRFLAG 18 /* true if poll_idle() is polling
+ TIF_NEED_RESCHED */
/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
@@ -126,13 +129,16 @@
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
#define _TIF_EMULATE_STACK_STORE (1<<TIF_EMULATE_STACK_STORE)
#define _TIF_NOHZ (1<<TIF_NOHZ)
+#define _TIF_NEED_RESCHED_LAZY (1<<TIF_NEED_RESCHED_LAZY)
#define _TIF_SYSCALL_T_OR_A (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
_TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
_TIF_NOHZ)
#define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
- _TIF_NOTIFY_RESUME | _TIF_UPROBE)
+ _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
+ _TIF_NEED_RESCHED_LAZY)
#define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR)
+#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
/* Bits in local_flags */
/* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 502c7a4..55210c0 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -165,6 +165,7 @@
DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
DEFINE(TI_LOCAL_FLAGS, offsetof(struct thread_info, local_flags));
DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
+ DEFINE(TI_PREEMPT_LAZY, offsetof(struct thread_info, preempt_lazy_count));
DEFINE(TI_TASK, offsetof(struct thread_info, task));
DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 22b45a4..081f926 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -890,7 +890,14 @@
cmpwi 0,r0,0 /* if non-zero, just restore regs and return */
bne restore
andi. r8,r8,_TIF_NEED_RESCHED
+ bne+ 1f
+ lwz r0,TI_PREEMPT_LAZY(r9)
+ cmpwi 0,r0,0 /* if non-zero, just restore regs and return */
+ bne restore
+ lwz r0,TI_FLAGS(r9)
+ andi. r0,r0,_TIF_NEED_RESCHED_LAZY
beq+ restore
+1:
lwz r3,_MSR(r1)
andi. r0,r3,MSR_EE /* interrupts off? */
beq restore /* don't schedule if so */
@@ -901,11 +908,11 @@
*/
bl trace_hardirqs_off
#endif
-1: bl preempt_schedule_irq
+2: bl preempt_schedule_irq
CURRENT_THREAD_INFO(r9, r1)
lwz r3,TI_FLAGS(r9)
- andi. r0,r3,_TIF_NEED_RESCHED
- bne- 1b
+ andi. r0,r3,_TIF_NEED_RESCHED_MASK
+ bne- 2b
#ifdef CONFIG_TRACE_IRQFLAGS
/* And now, to properly rebalance the above, we tell lockdep they
* are being turned back on, which will happen when we return
@@ -1226,7 +1233,7 @@
#endif /* !(CONFIG_4xx || CONFIG_BOOKE) */
do_work: /* r10 contains MSR_KERNEL here */
- andi. r0,r9,_TIF_NEED_RESCHED
+ andi. r0,r9,_TIF_NEED_RESCHED_MASK
beq do_user_signal
do_resched: /* r10 contains MSR_KERNEL here */
@@ -1247,7 +1254,7 @@
MTMSRD(r10) /* disable interrupts */
CURRENT_THREAD_INFO(r9, r1)
lwz r9,TI_FLAGS(r9)
- andi. r0,r9,_TIF_NEED_RESCHED
+ andi. r0,r9,_TIF_NEED_RESCHED_MASK
bne- do_resched
andi. r0,r9,_TIF_USER_WORK_MASK
beq restore_user
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 7be3717..e6bfe8e 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -659,7 +659,7 @@
#else
beq restore
#endif
-1: andi. r0,r4,_TIF_NEED_RESCHED
+1: andi. r0,r4,_TIF_NEED_RESCHED_MASK
beq 2f
bl .restore_interrupts
SCHEDULE_USER
@@ -709,10 +709,18 @@
#ifdef CONFIG_PREEMPT
/* Check if we need to preempt */
- andi. r0,r4,_TIF_NEED_RESCHED
- beq+ restore
- /* Check that preempt_count() == 0 and interrupts are enabled */
lwz r8,TI_PREEMPT(r9)
+ cmpwi 0,r8,0 /* if non-zero, just restore regs and return */
+ bne restore
+ andi. r0,r4,_TIF_NEED_RESCHED
+ bne+ check_count
+
+ andi. r0,r4,_TIF_NEED_RESCHED_LAZY
+ beq+ restore
+ lwz r8,TI_PREEMPT_LAZY(r9)
+
+ /* Check that preempt_count() == 0 and interrupts are enabled */
+check_count:
cmpwi cr1,r8,0
ld r0,SOFTE(r1)
cmpdi r0,0
@@ -729,7 +737,7 @@
/* Re-test flags and eventually loop */
CURRENT_THREAD_INFO(r9, r1)
ld r4,TI_FLAGS(r9)
- andi. r0,r4,_TIF_NEED_RESCHED
+ andi. r0,r4,_TIF_NEED_RESCHED_MASK
bne 1b
/*
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index c7cb8c2..f3ed55a 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -594,6 +594,7 @@
}
}
+#ifndef CONFIG_PREEMPT_RT_FULL
static inline void do_softirq_onstack(void)
{
struct thread_info *curtp, *irqtp;
@@ -626,6 +627,7 @@
local_irq_restore(flags);
}
+#endif
irq_hw_number_t virq_to_hw(unsigned int virq)
{
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index e23298f..2b2c669 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -40,6 +40,7 @@
* We store the saved ksp_limit in the unused part
* of the STACK_FRAME_OVERHEAD
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
_GLOBAL(call_do_softirq)
mflr r0
stw r0,4(r1)
@@ -56,6 +57,7 @@
stw r10,THREAD+KSP_LIMIT(r2)
mtlr r0
blr
+#endif
/*
* void call_do_irq(struct pt_regs *regs, struct thread_info *irqtp);
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index e59caf8..f93987e 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -29,6 +29,7 @@
.text
+#ifndef CONFIG_PREEMPT_RT_FULL
_GLOBAL(call_do_softirq)
mflr r0
std r0,16(r1)
@@ -39,6 +40,7 @@
ld r0,16(r1)
mtlr r0
blr
+#endif
_GLOBAL(call_do_irq)
mflr r0
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 62e7f22..945505e 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -423,7 +423,7 @@
EXPORT_SYMBOL(profile_pc);
#endif
-#ifdef CONFIG_IRQ_WORK
+#if defined(CONFIG_IRQ_WORK)
/*
* 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index ffaef2c..78c3c30 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -155,6 +155,7 @@
config KVM_MPIC
bool "KVM in-kernel MPIC emulation"
depends on KVM && E500
+ depends on !PREEMPT_RT_FULL
select HAVE_KVM_IRQCHIP
select HAVE_KVM_IRQ_ROUTING
select HAVE_KVM_MSI
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index ed6e0be..be7ea4d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -70,11 +70,11 @@
{
int me;
int cpu = vcpu->cpu;
- wait_queue_head_t *wqp;
+ struct swait_head *wqp;
wqp = kvm_arch_vcpu_wq(vcpu);
- if (waitqueue_active(wqp)) {
- wake_up_interruptible(wqp);
+ if (swaitqueue_active(wqp)) {
+ swait_wake_interruptible(wqp);
++vcpu->stat.halt_wakeup;
}
@@ -540,8 +540,8 @@
tvcpu->arch.prodded = 1;
smp_mb();
if (vcpu->arch.ceded) {
- if (waitqueue_active(&vcpu->wq)) {
- wake_up_interruptible(&vcpu->wq);
+ if (swaitqueue_active(&vcpu->wq)) {
+ swait_wake_interruptible(&vcpu->wq);
vcpu->stat.halt_wakeup++;
}
}
@@ -947,7 +947,7 @@
if (vcore) {
INIT_LIST_HEAD(&vcore->runnable_threads);
spin_lock_init(&vcore->lock);
- init_waitqueue_head(&vcore->wq);
+ init_swait_head(&vcore->wq);
vcore->preempt_tb = TB_NIL;
}
kvm->arch.vcores[core] = vcore;
@@ -1318,13 +1318,13 @@
*/
static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
{
- DEFINE_WAIT(wait);
+ DEFINE_SWAITER(wait);
- prepare_to_wait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
+ swait_prepare(&vc->wq, &wait, TASK_INTERRUPTIBLE);
vc->vcore_state = VCORE_SLEEPING;
spin_unlock(&vc->lock);
schedule();
- finish_wait(&vc->wq, &wait);
+ swait_finish(&vc->wq, &wait);
spin_lock(&vc->lock);
vc->vcore_state = VCORE_INACTIVE;
}
@@ -1366,7 +1366,7 @@
kvmppc_create_dtl_entry(vcpu, vc);
kvmppc_start_thread(vcpu);
} else if (vc->vcore_state == VCORE_SLEEPING) {
- wake_up(&vc->wq);
+ swait_wake(&vc->wq);
}
}
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 010fabf..018224a 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -261,7 +261,7 @@
if (!arch_irq_disabled_regs(regs))
local_irq_enable();
- if (in_atomic() || mm == NULL) {
+ if (in_atomic() || mm == NULL || pagefault_disabled()) {
if (!user_mode(regs)) {
rc = SIGSEGV;
goto bail;
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
index b69221b..2898b73 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
@@ -340,7 +340,7 @@
{
int l1irq;
int l2irq;
- struct irq_chip *irqchip;
+ struct irq_chip *uninitialized_var(irqchip);
void *hndlr;
int type;
u32 reg;
@@ -373,9 +373,8 @@
case MPC52xx_IRQ_L1_PERP: irqchip = &mpc52xx_periph_irqchip; break;
case MPC52xx_IRQ_L1_SDMA: irqchip = &mpc52xx_sdma_irqchip; break;
case MPC52xx_IRQ_L1_CRIT:
- default:
pr_warn("%s: Critical IRQ #%d is unsupported! Nopping it.\n",
- __func__, l1irq);
+ __func__, l2irq);
irq_set_chip(virq, &no_irq_chip);
return 0;
}
diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild
index f313f9c..f49df54 100644
--- a/arch/s390/include/asm/Kbuild
+++ b/arch/s390/include/asm/Kbuild
@@ -2,3 +2,4 @@
generic-y += clkdev.h
generic-y += trace_clock.h
+generic-y += irq_work.h
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index e87ecaa..295aab2 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -228,7 +228,7 @@
atomic_t active;
struct kvm_s390_float_interrupt *float_int;
int timer_due; /* event indicator for waitqueue below */
- wait_queue_head_t *wq;
+ struct swait_head *wq;
atomic_t *cpuflags;
unsigned int action_bits;
};
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index b53f37f..9de7aba 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -302,7 +302,8 @@
* user context.
*/
fault = VM_FAULT_BADCONTEXT;
- if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm))
+ if (unlikely(!user_space_fault(trans_exc_code) ||
+ !mm || pagefault_disabled()))
goto out;
address = trans_exc_code & __FAIL_ADDR_MASK;
@@ -448,7 +449,8 @@
clear_tsk_thread_flag(current, TIF_PER_TRAP);
trans_exc_code = regs->int_parm_long;
- if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm))
+ if (unlikely(!user_space_fault(trans_exc_code) || !mm ||
+ pagefault_disabled()))
goto no_context;
down_read(&mm->mmap_sem);
diff --git a/arch/score/include/asm/Kbuild b/arch/score/include/asm/Kbuild
index 825c718..06268ad 100644
--- a/arch/score/include/asm/Kbuild
+++ b/arch/score/include/asm/Kbuild
@@ -3,5 +3,6 @@
generic-y += clkdev.h
generic-y += trace_clock.h
+generic-y += irq_work.h
generic-y += xor.h
generic-y += barrier.h
diff --git a/arch/score/mm/fault.c b/arch/score/mm/fault.c
index 6860beb..b946291 100644
--- a/arch/score/mm/fault.c
+++ b/arch/score/mm/fault.c
@@ -73,7 +73,7 @@
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto bad_area_nosemaphore;
if (user_mode(regs))
diff --git a/arch/sh/include/asm/Kbuild b/arch/sh/include/asm/Kbuild
index 280bea9..6156f0d 100644
--- a/arch/sh/include/asm/Kbuild
+++ b/arch/sh/include/asm/Kbuild
@@ -11,6 +11,7 @@
generic-y += ioctl.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kvm_para.h
generic-y += local.h
generic-y += local64.h
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index 063af10..ae4b141 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -149,6 +149,7 @@
hardirq_ctx[cpu] = NULL;
}
+#ifndef CONFIG_PREEMPT_RT_FULL
asmlinkage void do_softirq(void)
{
unsigned long flags;
@@ -191,6 +192,7 @@
local_irq_restore(flags);
}
+#endif
#else
static inline void handle_one_irq(unsigned int irq)
{
diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c
index a58fec9..364cae5 100644
--- a/arch/sh/mm/fault.c
+++ b/arch/sh/mm/fault.c
@@ -440,7 +440,7 @@
* If we're in an interrupt, have no user context or are running
* in an atomic region then we must not take the fault:
*/
- if (unlikely(in_atomic() || !mm)) {
+ if (unlikely(!mm || pagefault_disabled())) {
bad_area_nosemaphore(regs, error_code, address);
return;
}
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 11068ae..3ff0c25 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -26,6 +26,7 @@
select HAVE_DMA_ATTRS
select HAVE_DMA_API_DEBUG
select HAVE_ARCH_JUMP_LABEL if SPARC64
+ select IRQ_FORCED_THREADING
select GENERIC_IRQ_SHOW
select ARCH_WANT_IPC_PARSE_VERSION
select USE_GENERIC_SMP_HELPERS if SMP
@@ -179,12 +180,10 @@
source kernel/Kconfig.hz
config RWSEM_GENERIC_SPINLOCK
- bool
- default y if SPARC32
+ def_bool PREEMPT_RT_FULL
config RWSEM_XCHGADD_ALGORITHM
- bool
- default y if SPARC64
+ def_bool !RWSEM_GENERIC_SPINLOCK && !PREEMPT_RT_FULL
config GENERIC_HWEIGHT
bool
@@ -525,6 +524,10 @@
source "fs/Kconfig.binfmt"
+config EARLY_PRINTK
+ bool
+ default y
+
config COMPAT
bool
depends on SPARC64
diff --git a/arch/sparc/include/asm/Kbuild b/arch/sparc/include/asm/Kbuild
index 7e4a97f..28bf27a 100644
--- a/arch/sparc/include/asm/Kbuild
+++ b/arch/sparc/include/asm/Kbuild
@@ -10,6 +10,7 @@
generic-y += local64.h
generic-y += mutex.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += local.h
generic-y += module.h
generic-y += serial.h
diff --git a/arch/sparc/include/asm/mmu_64.h b/arch/sparc/include/asm/mmu_64.h
index 4994815..ad0fc37 100644
--- a/arch/sparc/include/asm/mmu_64.h
+++ b/arch/sparc/include/asm/mmu_64.h
@@ -90,7 +90,7 @@
#endif
typedef struct {
- spinlock_t lock;
+ raw_spinlock_t lock;
unsigned long sparc64_ctx_val;
unsigned long hugetlb_pte_count;
unsigned long thp_pte_count;
diff --git a/arch/sparc/include/asm/mmu_context_64.h b/arch/sparc/include/asm/mmu_context_64.h
index 3d528f0..44e393b 100644
--- a/arch/sparc/include/asm/mmu_context_64.h
+++ b/arch/sparc/include/asm/mmu_context_64.h
@@ -13,7 +13,7 @@
{
}
-extern spinlock_t ctx_alloc_lock;
+extern raw_spinlock_t ctx_alloc_lock;
extern unsigned long tlb_context_cache;
extern unsigned long mmu_context_bmap[];
@@ -77,7 +77,7 @@
if (unlikely(mm == &init_mm))
return;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
ctx_valid = CTX_VALID(mm->context);
if (!ctx_valid)
get_new_mmu_context(mm);
@@ -125,7 +125,7 @@
__flush_tlb_mm(CTX_HWBITS(mm->context),
SECONDARY_CONTEXT);
}
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
}
#define deactivate_mm(tsk,mm) do { } while (0)
@@ -136,7 +136,7 @@
unsigned long flags;
int cpu;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
if (!CTX_VALID(mm->context))
get_new_mmu_context(mm);
cpu = smp_processor_id();
@@ -146,7 +146,7 @@
load_secondary_context(mm);
__flush_tlb_mm(CTX_HWBITS(mm->context), SECONDARY_CONTEXT);
tsb_context_switch(mm);
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
}
#endif /* !(__ASSEMBLY__) */
diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c
index 7c22f1c..6598b71 100644
--- a/arch/sparc/kernel/irq_64.c
+++ b/arch/sparc/kernel/irq_64.c
@@ -849,6 +849,7 @@
set_irq_regs(old_regs);
}
+#ifndef CONFIG_PREEMPT_RT_FULL
void do_softirq(void)
{
unsigned long flags;
@@ -874,6 +875,7 @@
local_irq_restore(flags);
}
+#endif
#ifdef CONFIG_HOTPLUG_CPU
void fixup_irqs(void)
diff --git a/arch/sparc/kernel/setup_32.c b/arch/sparc/kernel/setup_32.c
index 1434526..0884ccd 100644
--- a/arch/sparc/kernel/setup_32.c
+++ b/arch/sparc/kernel/setup_32.c
@@ -309,6 +309,7 @@
boot_flags_init(*cmdline_p);
+ early_console = &prom_early_console;
register_console(&prom_early_console);
printk("ARCH: ");
diff --git a/arch/sparc/kernel/setup_64.c b/arch/sparc/kernel/setup_64.c
index 61a5198..8ec28cc 100644
--- a/arch/sparc/kernel/setup_64.c
+++ b/arch/sparc/kernel/setup_64.c
@@ -575,6 +575,12 @@
pause_patch();
}
+static inline void register_prom_console(void)
+{
+ early_console = &prom_early_console;
+ register_console(&prom_early_console);
+}
+
void __init setup_arch(char **cmdline_p)
{
/* Initialize PROM console and command line. */
@@ -586,7 +592,7 @@
#ifdef CONFIG_EARLYFB
if (btext_find_display())
#endif
- register_console(&prom_early_console);
+ register_prom_console();
if (tlb_type == hypervisor)
printk("ARCH: SUN4V\n");
diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index 226ff1a..3f5c129 100644
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -980,12 +980,12 @@
if (unlikely(!mm || (mm == &init_mm)))
return;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
if (unlikely(!CTX_VALID(mm->context)))
get_new_mmu_context(mm);
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
load_secondary_context(mm);
__flush_tlb_mm(CTX_HWBITS(mm->context),
diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c
index 163c787..d9613e9 100644
--- a/arch/sparc/mm/fault_32.c
+++ b/arch/sparc/mm/fault_32.c
@@ -199,7 +199,7 @@
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto no_context;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c
index a21917c..9cc9b96 100644
--- a/arch/sparc/mm/fault_64.c
+++ b/arch/sparc/mm/fault_64.c
@@ -330,7 +330,7 @@
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (!mm || pagefault_disabled())
goto intr_or_no_mm;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index a648a8e..d454854 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -350,7 +350,7 @@
if (!pte_accessible(mm, pte))
return;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
if ((mm->context.hugetlb_pte_count || mm->context.thp_pte_count) &&
@@ -362,7 +362,7 @@
__update_mmu_tsb_insert(mm, MM_TSB_BASE, PAGE_SHIFT,
address, pte_val(pte));
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
}
void flush_dcache_page(struct page *page)
@@ -662,7 +662,7 @@
EXPORT_SYMBOL(__flush_dcache_range);
/* get_new_mmu_context() uses "cache + 1". */
-DEFINE_SPINLOCK(ctx_alloc_lock);
+DEFINE_RAW_SPINLOCK(ctx_alloc_lock);
unsigned long tlb_context_cache = CTX_FIRST_VERSION - 1;
#define MAX_CTX_NR (1UL << CTX_NR_BITS)
#define CTX_BMAP_SLOTS BITS_TO_LONGS(MAX_CTX_NR)
@@ -684,7 +684,7 @@
unsigned long orig_pgsz_bits;
int new_version;
- spin_lock(&ctx_alloc_lock);
+ raw_spin_lock(&ctx_alloc_lock);
orig_pgsz_bits = (mm->context.sparc64_ctx_val & CTX_PGSZ_MASK);
ctx = (tlb_context_cache + 1) & CTX_NR_MASK;
new_ctx = find_next_zero_bit(mmu_context_bmap, 1 << CTX_NR_BITS, ctx);
@@ -720,7 +720,7 @@
out:
tlb_context_cache = new_ctx;
mm->context.sparc64_ctx_val = new_ctx | orig_pgsz_bits;
- spin_unlock(&ctx_alloc_lock);
+ raw_spin_unlock(&ctx_alloc_lock);
if (unlikely(new_version))
smp_new_mmu_context_version();
@@ -2734,7 +2734,7 @@
bool need_context_reload = false;
unsigned long ctx;
- spin_lock_irq(&ctx_alloc_lock);
+ raw_spin_lock_irq(&ctx_alloc_lock);
ctx = mm->context.sparc64_ctx_val;
ctx &= ~CTX_PGSZ_MASK;
ctx |= CTX_PGSZ_BASE << CTX_PGSZ0_SHIFT;
@@ -2755,7 +2755,7 @@
mm->context.sparc64_ctx_val = ctx;
need_context_reload = true;
}
- spin_unlock_irq(&ctx_alloc_lock);
+ raw_spin_unlock_irq(&ctx_alloc_lock);
if (need_context_reload)
on_each_cpu(context_reload, mm, 0);
diff --git a/arch/sparc/mm/tsb.c b/arch/sparc/mm/tsb.c
index 48a09e4..ae89e5b 100644
--- a/arch/sparc/mm/tsb.c
+++ b/arch/sparc/mm/tsb.c
@@ -90,7 +90,7 @@
struct mm_struct *mm = tb->mm;
unsigned long nentries, base, flags;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
@@ -107,14 +107,14 @@
__flush_tsb_one(tb, REAL_HPAGE_SHIFT, base, nentries);
}
#endif
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
}
void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr)
{
unsigned long nentries, base, flags;
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
@@ -131,7 +131,7 @@
__flush_tsb_one_entry(base, vaddr, REAL_HPAGE_SHIFT, nentries);
}
#endif
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
}
#define HV_PGSZ_IDX_BASE HV_PGSZ_IDX_8K
@@ -421,7 +421,7 @@
* the lock and ask all other cpus running this address space
* to run tsb_context_switch() to see the new TSB table.
*/
- spin_lock_irqsave(&mm->context.lock, flags);
+ raw_spin_lock_irqsave(&mm->context.lock, flags);
old_tsb = mm->context.tsb_block[tsb_index].tsb;
old_cache_index =
@@ -436,7 +436,7 @@
*/
if (unlikely(old_tsb &&
(rss < mm->context.tsb_block[tsb_index].tsb_rss_limit))) {
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
kmem_cache_free(tsb_caches[new_cache_index], new_tsb);
return;
@@ -462,7 +462,7 @@
mm->context.tsb_block[tsb_index].tsb = new_tsb;
setup_tsb_params(mm, tsb_index, new_size);
- spin_unlock_irqrestore(&mm->context.lock, flags);
+ raw_spin_unlock_irqrestore(&mm->context.lock, flags);
/* If old_tsb is NULL, we're being invoked for the first time
* from init_new_context().
@@ -488,7 +488,7 @@
#endif
unsigned int i;
- spin_lock_init(&mm->context.lock);
+ raw_spin_lock_init(&mm->context.lock);
mm->context.sparc64_ctx_val = 0UL;
@@ -545,12 +545,12 @@
for (i = 0; i < MM_NUM_TSBS; i++)
tsb_destroy_one(&mm->context.tsb_block[i]);
- spin_lock_irqsave(&ctx_alloc_lock, flags);
+ raw_spin_lock_irqsave(&ctx_alloc_lock, flags);
if (CTX_VALID(mm->context)) {
unsigned long nr = CTX_NRBITS(mm->context);
mmu_context_bmap[nr>>6] &= ~(1UL << (nr & 63));
}
- spin_unlock_irqrestore(&ctx_alloc_lock, flags);
+ raw_spin_unlock_irqrestore(&ctx_alloc_lock, flags);
}
diff --git a/arch/tile/include/asm/Kbuild b/arch/tile/include/asm/Kbuild
index 664d6ad..6541485 100644
--- a/arch/tile/include/asm/Kbuild
+++ b/arch/tile/include/asm/Kbuild
@@ -16,6 +16,7 @@
generic-y += ioctls.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += local.h
generic-y += local64.h
generic-y += msgbuf.h
diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c
index c6d2a76..4cdab26 100644
--- a/arch/tile/mm/fault.c
+++ b/arch/tile/mm/fault.c
@@ -357,7 +357,7 @@
* If we're in an interrupt, have no user context or are running in an
* atomic region then we must not take the fault.
*/
- if (in_atomic() || !mm) {
+ if (!mm || pagefault_disabled()) {
vma = NULL; /* happy compiler */
goto bad_area_nosemaphore;
}
diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild
index b30f34a..3c3d58a 100644
--- a/arch/um/include/asm/Kbuild
+++ b/arch/um/include/asm/Kbuild
@@ -3,3 +3,4 @@
generic-y += ftrace.h pci.h io.h param.h delay.h mutex.h current.h exec.h
generic-y += switch_to.h clkdev.h
generic-y += trace_clock.h
+generic-y += irq_work.h
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 06ab0eb..c5980e8 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -38,7 +38,7 @@
* If the fault was during atomic operation, don't take the fault, just
* fail.
*/
- if (in_atomic())
+ if (pagefault_disabled())
goto out_nosemaphore;
if (is_user)
diff --git a/arch/unicore32/include/asm/Kbuild b/arch/unicore32/include/asm/Kbuild
index 89d8b6c..2be70e6 100644
--- a/arch/unicore32/include/asm/Kbuild
+++ b/arch/unicore32/include/asm/Kbuild
@@ -21,6 +21,7 @@
generic-y += ioctls.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += local.h
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7255e3d..344c250 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -21,6 +21,7 @@
### Arch settings
config X86
def_bool y
+ select HAVE_PREEMPT_LAZY
select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
select HAVE_AOUT if X86_32
select HAVE_UNSTABLE_SCHED_CLOCK
@@ -180,8 +181,11 @@
def_bool y
depends on ISA_DMA_API
+config RWSEM_GENERIC_SPINLOCK
+ def_bool PREEMPT_RT_FULL
+
config RWSEM_XCHGADD_ALGORITHM
- def_bool y
+ def_bool !RWSEM_GENERIC_SPINLOCK && !PREEMPT_RT_FULL
config GENERIC_CALIBRATE_DELAY
def_bool y
@@ -471,7 +475,7 @@
select MFD_INTEL_MSIC
---help---
Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
- Internet Device(MID) platform.
+ Internet Device(MID) platform.
Unlike standard x86 PCs, Medfield does not have many legacy devices
nor standard legacy replacement devices/features. e.g. Medfield does
not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
@@ -818,7 +822,7 @@
config MAXSMP
bool "Enable Maximum number of SMP Processors and NUMA Nodes"
depends on X86_64 && SMP && DEBUG_KERNEL
- select CPUMASK_OFFSTACK
+ select CPUMASK_OFFSTACK if !PREEMPT_RT_FULL
---help---
Enable maximum number of CPUS and NUMA Nodes for this architecture.
If unsure, say N.
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 990c969..08bcc04 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -252,14 +252,14 @@
err = blkcipher_walk_virt(desc, &walk);
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_ecb_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
- nbytes & AES_BLOCK_MASK);
+ nbytes & AES_BLOCK_MASK);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -276,14 +276,14 @@
err = blkcipher_walk_virt(desc, &walk);
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_ecb_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -300,14 +300,14 @@
err = blkcipher_walk_virt(desc, &walk);
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_cbc_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK, walk.iv);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -324,14 +324,14 @@
err = blkcipher_walk_virt(desc, &walk);
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
- kernel_fpu_begin();
while ((nbytes = walk.nbytes)) {
+ kernel_fpu_begin();
aesni_cbc_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK, walk.iv);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- kernel_fpu_end();
return err;
}
@@ -364,18 +364,20 @@
err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
- kernel_fpu_begin();
while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
+ kernel_fpu_begin();
aesni_ctr_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
nbytes & AES_BLOCK_MASK, walk.iv);
+ kernel_fpu_end();
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
if (walk.nbytes) {
+ kernel_fpu_begin();
ctr_crypt_final(ctx, &walk);
+ kernel_fpu_end();
err = blkcipher_walk_done(desc, &walk, 0);
}
- kernel_fpu_end();
return err;
}
diff --git a/arch/x86/crypto/cast5_avx_glue.c b/arch/x86/crypto/cast5_avx_glue.c
index d416069..a0c7f10 100644
--- a/arch/x86/crypto/cast5_avx_glue.c
+++ b/arch/x86/crypto/cast5_avx_glue.c
@@ -60,7 +60,7 @@
static int ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
bool enc)
{
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct cast5_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
const unsigned int bsize = CAST5_BLOCK_SIZE;
unsigned int nbytes;
@@ -76,7 +76,7 @@
u8 *wsrc = walk->src.virt.addr;
u8 *wdst = walk->dst.virt.addr;
- fpu_enabled = cast5_fpu_begin(fpu_enabled, nbytes);
+ fpu_enabled = cast5_fpu_begin(false, nbytes);
/* Process multi-block batch */
if (nbytes >= bsize * CAST5_PARALLEL_BLOCKS) {
@@ -104,10 +104,9 @@
} while (nbytes >= bsize);
done:
+ cast5_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, walk, nbytes);
}
-
- cast5_fpu_end(fpu_enabled);
return err;
}
@@ -231,7 +230,7 @@
static int cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct blkcipher_walk walk;
int err;
@@ -240,12 +239,11 @@
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
while ((nbytes = walk.nbytes)) {
- fpu_enabled = cast5_fpu_begin(fpu_enabled, nbytes);
+ fpu_enabled = cast5_fpu_begin(false, nbytes);
nbytes = __cbc_decrypt(desc, &walk);
+ cast5_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, &walk, nbytes);
}
-
- cast5_fpu_end(fpu_enabled);
return err;
}
@@ -315,7 +313,7 @@
static int ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct blkcipher_walk walk;
int err;
@@ -324,13 +322,12 @@
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
while ((nbytes = walk.nbytes) >= CAST5_BLOCK_SIZE) {
- fpu_enabled = cast5_fpu_begin(fpu_enabled, nbytes);
+ fpu_enabled = cast5_fpu_begin(false, nbytes);
nbytes = __ctr_crypt(desc, &walk);
+ cast5_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- cast5_fpu_end(fpu_enabled);
-
if (walk.nbytes) {
ctr_crypt_final(desc, &walk);
err = blkcipher_walk_done(desc, &walk, 0);
diff --git a/arch/x86/crypto/glue_helper.c b/arch/x86/crypto/glue_helper.c
index 432f1d76..4a2bd21 100644
--- a/arch/x86/crypto/glue_helper.c
+++ b/arch/x86/crypto/glue_helper.c
@@ -39,7 +39,7 @@
void *ctx = crypto_blkcipher_ctx(desc->tfm);
const unsigned int bsize = 128 / 8;
unsigned int nbytes, i, func_bytes;
- bool fpu_enabled = false;
+ bool fpu_enabled;
int err;
err = blkcipher_walk_virt(desc, walk);
@@ -49,7 +49,7 @@
u8 *wdst = walk->dst.virt.addr;
fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
- desc, fpu_enabled, nbytes);
+ desc, false, nbytes);
for (i = 0; i < gctx->num_funcs; i++) {
func_bytes = bsize * gctx->funcs[i].num_blocks;
@@ -71,10 +71,10 @@
}
done:
+ glue_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, walk, nbytes);
}
- glue_fpu_end(fpu_enabled);
return err;
}
@@ -194,7 +194,7 @@
struct scatterlist *src, unsigned int nbytes)
{
const unsigned int bsize = 128 / 8;
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct blkcipher_walk walk;
int err;
@@ -203,12 +203,12 @@
while ((nbytes = walk.nbytes)) {
fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
- desc, fpu_enabled, nbytes);
+ desc, false, nbytes);
nbytes = __glue_cbc_decrypt_128bit(gctx, desc, &walk);
+ glue_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- glue_fpu_end(fpu_enabled);
return err;
}
EXPORT_SYMBOL_GPL(glue_cbc_decrypt_128bit);
@@ -278,7 +278,7 @@
struct scatterlist *src, unsigned int nbytes)
{
const unsigned int bsize = 128 / 8;
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct blkcipher_walk walk;
int err;
@@ -287,13 +287,12 @@
while ((nbytes = walk.nbytes) >= bsize) {
fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
- desc, fpu_enabled, nbytes);
+ desc, false, nbytes);
nbytes = __glue_ctr_crypt_128bit(gctx, desc, &walk);
+ glue_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- glue_fpu_end(fpu_enabled);
-
if (walk.nbytes) {
glue_ctr_crypt_final_128bit(
gctx->funcs[gctx->num_funcs - 1].fn_u.ctr, desc, &walk);
@@ -348,7 +347,7 @@
void *tweak_ctx, void *crypt_ctx)
{
const unsigned int bsize = 128 / 8;
- bool fpu_enabled = false;
+ bool fpu_enabled;
struct blkcipher_walk walk;
int err;
@@ -361,21 +360,21 @@
/* set minimum length to bsize, for tweak_fn */
fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
- desc, fpu_enabled,
+ desc, false,
nbytes < bsize ? bsize : nbytes);
-
/* calculate first value of T */
tweak_fn(tweak_ctx, walk.iv, walk.iv);
+ glue_fpu_end(fpu_enabled);
while (nbytes) {
+ fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
+ desc, false, nbytes);
nbytes = __glue_xts_crypt_128bit(gctx, crypt_ctx, desc, &walk);
+ glue_fpu_end(fpu_enabled);
err = blkcipher_walk_done(desc, &walk, nbytes);
nbytes = walk.nbytes;
}
-
- glue_fpu_end(fpu_enabled);
-
return err;
}
EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit);
diff --git a/arch/x86/include/asm/irq_work.h b/arch/x86/include/asm/irq_work.h
new file mode 100644
index 0000000..78162f8
--- /dev/null
+++ b/arch/x86/include/asm/irq_work.h
@@ -0,0 +1,11 @@
+#ifndef _ASM_IRQ_WORK_H
+#define _ASM_IRQ_WORK_H
+
+#include <asm/processor.h>
+
+static inline bool arch_irq_work_has_interrupt(void)
+{
+ return cpu_has_apic;
+}
+
+#endif /* _ASM_IRQ_WORK_H */
diff --git a/arch/x86/include/asm/signal.h b/arch/x86/include/asm/signal.h
index 35e67a4..6ec0792 100644
--- a/arch/x86/include/asm/signal.h
+++ b/arch/x86/include/asm/signal.h
@@ -23,6 +23,19 @@
unsigned long sig[_NSIG_WORDS];
} sigset_t;
+/*
+ * Because some traps use the IST stack, we must keep preemption
+ * disabled while calling do_trap(), but do_trap() may call
+ * force_sig_info() which will grab the signal spin_locks for the
+ * task, which in PREEMPT_RT_FULL are mutexes. By defining
+ * ARCH_RT_DELAYS_SIGNAL_SEND the force_sig_info() will set
+ * TIF_NOTIFY_RESUME and set up the signal to be sent on exit of the
+ * trap.
+ */
+#if defined(CONFIG_PREEMPT_RT_FULL) && defined(CONFIG_X86_64)
+#define ARCH_RT_DELAYS_SIGNAL_SEND
+#endif
+
#ifndef CONFIG_COMPAT
typedef sigset_t compat_sigset_t;
#endif
diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h
index 6a99859..64fb5cb 100644
--- a/arch/x86/include/asm/stackprotector.h
+++ b/arch/x86/include/asm/stackprotector.h
@@ -57,7 +57,7 @@
*/
static __always_inline void boot_init_stack_canary(void)
{
- u64 canary;
+ u64 uninitialized_var(canary);
u64 tsc;
#ifdef CONFIG_X86_64
@@ -68,8 +68,16 @@
* of randomness. The TSC only matters for very early init,
* there it already has some randomness on most systems. Later
* on during the bootup the random pool has true entropy too.
+ *
+ * For preempt-rt we need to weaken the randomness a bit, as
+ * we can't call into the random generator from atomic context
+ * due to locking constraints. We just leave canary
+ * uninitialized and use the TSC based randomness on top of
+ * it.
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
get_random_bytes(&canary, sizeof(canary));
+#endif
tsc = __native_read_tsc();
canary += tsc + (tsc << 32UL);
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index bbbac92..b188292 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -30,6 +30,8 @@
__u32 cpu; /* current CPU */
int preempt_count; /* 0 => preemptable,
<0 => BUG */
+ int preempt_lazy_count; /* 0 => lazy preemptable,
+ <0 => BUG */
mm_segment_t addr_limit;
struct restart_block restart_block;
void __user *sysenter_return;
@@ -81,6 +83,7 @@
#define TIF_SYSCALL_EMU 6 /* syscall emulation active */
#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
#define TIF_SECCOMP 8 /* secure computing */
+#define TIF_NEED_RESCHED_LAZY 9 /* lazy rescheduling necessary */
#define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
#define TIF_UPROBE 12 /* breakpointed or singlestepping */
@@ -105,6 +108,7 @@
#define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
+#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY)
#define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY)
#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
#define _TIF_UPROBE (1 << TIF_UPROBE)
@@ -154,6 +158,8 @@
#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
+#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
+
#define PREEMPT_ACTIVE 0x10000000
#ifdef CONFIG_X86_32
diff --git a/arch/x86/include/asm/uv/uv_bau.h b/arch/x86/include/asm/uv/uv_bau.h
index 0b46ef2..c2c8a78 100644
--- a/arch/x86/include/asm/uv/uv_bau.h
+++ b/arch/x86/include/asm/uv/uv_bau.h
@@ -611,9 +611,9 @@
cycles_t send_message;
cycles_t period_end;
cycles_t period_time;
- spinlock_t uvhub_lock;
- spinlock_t queue_lock;
- spinlock_t disable_lock;
+ raw_spinlock_t uvhub_lock;
+ raw_spinlock_t queue_lock;
+ raw_spinlock_t disable_lock;
/* tunables */
int max_concurr;
int max_concurr_const;
@@ -773,15 +773,15 @@
* to be lowered below the current 'v'. atomic_add_unless can only stop
* on equal.
*/
-static inline int atomic_inc_unless_ge(spinlock_t *lock, atomic_t *v, int u)
+static inline int atomic_inc_unless_ge(raw_spinlock_t *lock, atomic_t *v, int u)
{
- spin_lock(lock);
+ raw_spin_lock(lock);
if (atomic_read(v) >= u) {
- spin_unlock(lock);
+ raw_spin_unlock(lock);
return 0;
}
atomic_inc(v);
- spin_unlock(lock);
+ raw_spin_unlock(lock);
return 1;
}
diff --git a/arch/x86/include/asm/uv/uv_hub.h b/arch/x86/include/asm/uv/uv_hub.h
index 2c32df9..2c676e8 100644
--- a/arch/x86/include/asm/uv/uv_hub.h
+++ b/arch/x86/include/asm/uv/uv_hub.h
@@ -502,7 +502,7 @@
unsigned short nr_online_cpus;
unsigned short pnode;
short memory_nid;
- spinlock_t nmi_lock;
+ raw_spinlock_t nmi_lock;
unsigned long nmi_count;
};
extern struct uv_blade_info *uv_blade_info;
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index e63a5bd..5816e6a 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2396,7 +2396,8 @@
static inline bool ioapic_irqd_mask(struct irq_data *data, struct irq_cfg *cfg)
{
/* If we are moving the irq we need to mask it */
- if (unlikely(irqd_is_setaffinity_pending(data))) {
+ if (unlikely(irqd_is_setaffinity_pending(data) &&
+ !irqd_irq_inprogress(data))) {
mask_ioapic(cfg);
return true;
}
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index a419814..1d5859e 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -980,7 +980,7 @@
uv_blade_info[blade].pnode = pnode;
uv_blade_info[blade].nr_possible_cpus = 0;
uv_blade_info[blade].nr_online_cpus = 0;
- spin_lock_init(&uv_blade_info[blade].nmi_lock);
+ raw_spin_lock_init(&uv_blade_info[blade].nmi_lock);
min_pnode = min(pnode, min_pnode);
max_pnode = max(pnode, max_pnode);
blade++;
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 2861082..a36d9cf 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -33,6 +33,7 @@
OFFSET(TI_status, thread_info, status);
OFFSET(TI_addr_limit, thread_info, addr_limit);
OFFSET(TI_preempt_count, thread_info, preempt_count);
+ OFFSET(TI_preempt_lazy_count, thread_info, preempt_lazy_count);
BLANK();
OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx);
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index b3218cd..9901b77 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -18,6 +18,7 @@
#include <linux/rcupdate.h>
#include <linux/kobject.h>
#include <linux/uaccess.h>
+#include <linux/kthread.h>
#include <linux/kdebug.h>
#include <linux/kernel.h>
#include <linux/percpu.h>
@@ -41,6 +42,7 @@
#include <linux/debugfs.h>
#include <linux/irq_work.h>
#include <linux/export.h>
+#include <linux/jiffies.h>
#include <asm/processor.h>
#include <asm/mce.h>
@@ -1268,7 +1270,7 @@
static unsigned long check_interval = 5 * 60; /* 5 minutes */
static DEFINE_PER_CPU(unsigned long, mce_next_interval); /* in jiffies */
-static DEFINE_PER_CPU(struct timer_list, mce_timer);
+static DEFINE_PER_CPU(struct hrtimer, mce_timer);
static unsigned long mce_adjust_timer_default(unsigned long interval)
{
@@ -1278,13 +1280,10 @@
static unsigned long (*mce_adjust_timer)(unsigned long interval) =
mce_adjust_timer_default;
-static void mce_timer_fn(unsigned long data)
+static enum hrtimer_restart mce_timer_fn(struct hrtimer *timer)
{
- struct timer_list *t = &__get_cpu_var(mce_timer);
unsigned long iv;
- WARN_ON(smp_processor_id() != data);
-
if (mce_available(__this_cpu_ptr(&cpu_info))) {
machine_check_poll(MCP_TIMESTAMP,
&__get_cpu_var(mce_poll_banks));
@@ -1305,9 +1304,11 @@
__this_cpu_write(mce_next_interval, iv);
/* Might have become 0 after CMCI storm subsided */
if (iv) {
- t->expires = jiffies + iv;
- add_timer_on(t, smp_processor_id());
+ hrtimer_forward_now(timer, ns_to_ktime(
+ jiffies_to_usecs(iv) * 1000ULL));
+ return HRTIMER_RESTART;
}
+ return HRTIMER_NORESTART;
}
/*
@@ -1315,28 +1316,37 @@
*/
void mce_timer_kick(unsigned long interval)
{
- struct timer_list *t = &__get_cpu_var(mce_timer);
- unsigned long when = jiffies + interval;
+ struct hrtimer *t = &__get_cpu_var(mce_timer);
unsigned long iv = __this_cpu_read(mce_next_interval);
- if (timer_pending(t)) {
- if (time_before(when, t->expires))
- mod_timer_pinned(t, when);
+ if (hrtimer_active(t)) {
+ s64 exp;
+ s64 intv_us;
+
+ intv_us = jiffies_to_usecs(interval);
+ exp = ktime_to_us(hrtimer_expires_remaining(t));
+ if (intv_us < exp) {
+ hrtimer_cancel(t);
+ hrtimer_start_range_ns(t,
+ ns_to_ktime(intv_us * 1000),
+ 0, HRTIMER_MODE_REL_PINNED);
+ }
} else {
- t->expires = round_jiffies(when);
- add_timer_on(t, smp_processor_id());
+ hrtimer_start_range_ns(t,
+ ns_to_ktime(jiffies_to_usecs(interval) * 1000ULL),
+ 0, HRTIMER_MODE_REL_PINNED);
}
if (interval < iv)
__this_cpu_write(mce_next_interval, interval);
}
-/* Must not be called in IRQ context where del_timer_sync() can deadlock */
+/* Must not be called in IRQ context where hrtimer_cancel() can deadlock */
static void mce_timer_delete_all(void)
{
int cpu;
for_each_online_cpu(cpu)
- del_timer_sync(&per_cpu(mce_timer, cpu));
+ hrtimer_cancel(&per_cpu(mce_timer, cpu));
}
static void mce_do_trigger(struct work_struct *work)
@@ -1346,6 +1356,64 @@
static DECLARE_WORK(mce_trigger_work, mce_do_trigger);
+static void __mce_notify_work(void)
+{
+ /* Not more than two messages every minute */
+ static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);
+
+ /* wake processes polling /dev/mcelog */
+ wake_up_interruptible(&mce_chrdev_wait);
+
+ /*
+ * There is no risk of missing notifications because
+ * work_pending is always cleared before the function is
+ * executed.
+ */
+ if (mce_helper[0] && !work_pending(&mce_trigger_work))
+ schedule_work(&mce_trigger_work);
+
+ if (__ratelimit(&ratelimit))
+ pr_info(HW_ERR "Machine check events logged\n");
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+struct task_struct *mce_notify_helper;
+
+static int mce_notify_helper_thread(void *unused)
+{
+ while (1) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ if (kthread_should_stop())
+ break;
+ __mce_notify_work();
+ }
+ return 0;
+}
+
+static int mce_notify_work_init(void)
+{
+ mce_notify_helper = kthread_run(mce_notify_helper_thread, NULL,
+ "mce-notify");
+ if (!mce_notify_helper)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void mce_notify_work(void)
+{
+ if (mce_notify_helper)
+ wake_up_process(mce_notify_helper);
+}
+#else
+static void mce_notify_work(void)
+{
+ __mce_notify_work();
+}
+static inline int mce_notify_work_init(void) { return 0; }
+#endif
+
/*
* Notify the user(s) about new machine check events.
* Can be called from interrupt context, but not from machine check/NMI
@@ -1353,19 +1421,8 @@
*/
int mce_notify_irq(void)
{
- /* Not more than two messages every minute */
- static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);
-
if (test_and_clear_bit(0, &mce_need_notify)) {
- /* wake processes polling /dev/mcelog */
- wake_up_interruptible(&mce_chrdev_wait);
-
- if (mce_helper[0])
- schedule_work(&mce_trigger_work);
-
- if (__ratelimit(&ratelimit))
- pr_info(HW_ERR "Machine check events logged\n");
-
+ mce_notify_work();
return 1;
}
return 0;
@@ -1636,7 +1693,7 @@
}
}
-static void mce_start_timer(unsigned int cpu, struct timer_list *t)
+static void mce_start_timer(unsigned int cpu, struct hrtimer *t)
{
unsigned long iv = mce_adjust_timer(check_interval * HZ);
@@ -1645,16 +1702,17 @@
if (mca_cfg.ignore_ce || !iv)
return;
- t->expires = round_jiffies(jiffies + iv);
- add_timer_on(t, smp_processor_id());
+ hrtimer_start_range_ns(t, ns_to_ktime(jiffies_to_usecs(iv) * 1000ULL),
+ 0, HRTIMER_MODE_REL_PINNED);
}
static void __mcheck_cpu_init_timer(void)
{
- struct timer_list *t = &__get_cpu_var(mce_timer);
+ struct hrtimer *t = &__get_cpu_var(mce_timer);
unsigned int cpu = smp_processor_id();
- setup_timer(t, mce_timer_fn, cpu);
+ hrtimer_init(t, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ t->function = mce_timer_fn;
mce_start_timer(cpu, t);
}
@@ -2329,6 +2387,8 @@
if (!mce_available(__this_cpu_ptr(&cpu_info)))
return;
+ hrtimer_cancel(&__get_cpu_var(mce_timer));
+
if (!(action & CPU_TASKS_FROZEN))
cmci_clear();
for (i = 0; i < mca_cfg.banks; i++) {
@@ -2355,6 +2415,7 @@
if (b->init)
wrmsrl(MSR_IA32_MCx_CTL(i), b->ctl);
}
+ __mcheck_cpu_init_timer();
}
/* Get notified when a cpu comes on/off. Be hotplug friendly. */
@@ -2362,7 +2423,6 @@
mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
- struct timer_list *t = &per_cpu(mce_timer, cpu);
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
@@ -2378,11 +2438,9 @@
break;
case CPU_DOWN_PREPARE:
smp_call_function_single(cpu, mce_disable_cpu, &action, 1);
- del_timer_sync(t);
break;
case CPU_DOWN_FAILED:
smp_call_function_single(cpu, mce_reenable_cpu, &action, 1);
- mce_start_timer(cpu, t);
break;
}
@@ -2444,6 +2502,8 @@
/* register character device /dev/mcelog */
misc_register(&mce_chrdev_device);
+ err = mce_notify_work_init();
+
return err;
}
device_initcall_sync(mcheck_init_device);
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 66e274a..37aee50 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -114,7 +114,7 @@
unsigned long *stack, unsigned long bp,
const struct stacktrace_ops *ops, void *data)
{
- const unsigned cpu = get_cpu();
+ const unsigned cpu = get_cpu_light();
unsigned long *irq_stack_end =
(unsigned long *)per_cpu(irq_stack_ptr, cpu);
unsigned used = 0;
@@ -191,7 +191,7 @@
* This handles the process stack:
*/
bp = ops->walk_stack(tinfo, stack, bp, ops, data, NULL, &graph);
- put_cpu();
+ put_cpu_light();
}
EXPORT_SYMBOL(dump_trace);
@@ -205,7 +205,7 @@
int cpu;
int i;
- preempt_disable();
+ migrate_disable();
cpu = smp_processor_id();
irq_stack_end = (unsigned long *)(per_cpu(irq_stack_ptr, cpu));
@@ -238,7 +238,7 @@
pr_cont(" %016lx", *stack++);
touch_nmi_watchdog();
}
- preempt_enable();
+ migrate_enable();
pr_cont("\n");
show_trace_log_lvl(task, regs, sp, bp, log_lvl);
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index a78db5e..5891d57 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -364,14 +364,22 @@
DISABLE_INTERRUPTS(CLBR_ANY)
cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
jnz restore_all
-need_resched:
movl TI_flags(%ebp), %ecx # need_resched set ?
testb $_TIF_NEED_RESCHED, %cl
+ jnz 1f
+
+ cmpl $0,TI_preempt_lazy_count(%ebp) # non-zero preempt_lazy_count ?
+ jnz restore_all
+ testl $_TIF_NEED_RESCHED_LAZY, %ecx
jz restore_all
- testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off (exception path) ?
+
+1: testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off (exception path) ?
jz restore_all
call preempt_schedule_irq
- jmp need_resched
+ movl TI_flags(%ebp), %ecx # need_resched set ?
+ testl $_TIF_NEED_RESCHED_MASK, %ecx
+ jnz 1b
+ jmp restore_all
END(resume_kernel)
#endif
CFI_ENDPROC
@@ -608,7 +616,7 @@
ALIGN
RING0_PTREGS_FRAME # can't unwind into user space anyway
work_pending:
- testb $_TIF_NEED_RESCHED, %cl
+ testl $_TIF_NEED_RESCHED_MASK, %ecx
jz work_notifysig
work_resched:
call schedule
@@ -621,7 +629,7 @@
andl $_TIF_WORK_MASK, %ecx # is there any work to be done other
# than syscall tracing?
jz restore_all
- testb $_TIF_NEED_RESCHED, %cl
+ testl $_TIF_NEED_RESCHED_MASK, %ecx
jnz work_resched
work_notifysig: # deal with pending signals and
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index ceb8d11..e352dc5 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -663,8 +663,8 @@
/* Handle reschedules */
/* edx: work, edi: workmask */
sysret_careful:
- bt $TIF_NEED_RESCHED,%edx
- jnc sysret_signal
+ testl $_TIF_NEED_RESCHED_MASK,%edx
+ jz sysret_signal
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
pushq_cfi %rdi
@@ -776,8 +776,8 @@
/* First do a reschedule test. */
/* edx: work, edi: workmask */
int_careful:
- bt $TIF_NEED_RESCHED,%edx
- jnc int_very_careful
+ testl $_TIF_NEED_RESCHED_MASK,%edx
+ jz int_very_careful
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
pushq_cfi %rdi
@@ -1096,8 +1096,8 @@
/* edi: workmask, edx: work */
retint_careful:
CFI_RESTORE_STATE
- bt $TIF_NEED_RESCHED,%edx
- jnc retint_signal
+ testl $_TIF_NEED_RESCHED_MASK,%edx
+ jz retint_signal
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
pushq_cfi %rdi
@@ -1130,9 +1130,15 @@
ENTRY(retint_kernel)
cmpl $0,TI_preempt_count(%rcx)
jnz retint_restore_args
- bt $TIF_NEED_RESCHED,TI_flags(%rcx)
+ bt $TIF_NEED_RESCHED,TI_flags(%rcx)
+ jc 1f
+
+ cmpl $0,TI_preempt_lazy_count(%rcx)
+ jnz retint_restore_args
+ bt $TIF_NEED_RESCHED_LAZY,TI_flags(%rcx)
jnc retint_restore_args
- bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */
+
+1: bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */
jnc retint_restore_args
call preempt_schedule_irq
jmp exit_intr
@@ -1366,6 +1372,7 @@
jmp 2b
.previous
+#ifndef CONFIG_PREEMPT_RT_FULL
/* Call softirq on interrupt stack. Interrupts are off. */
ENTRY(call_softirq)
CFI_STARTPROC
@@ -1385,6 +1392,7 @@
ret
CFI_ENDPROC
END(call_softirq)
+#endif
#ifdef CONFIG_XEN
zeroentry xen_hypervisor_callback xen_do_hypervisor_callback
@@ -1554,7 +1562,7 @@
movq %rsp,%rdi /* &pt_regs */
call sync_regs
movq %rax,%rsp /* switch stack for scheduling */
- testl $_TIF_NEED_RESCHED,%ebx
+ testl $_TIF_NEED_RESCHED_MASK,%ebx
jnz paranoid_schedule
movl %ebx,%edx /* arg3: thread flags */
TRACE_IRQS_ON
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index 4186755..9da1bc7 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -149,6 +149,7 @@
cpu, per_cpu(hardirq_ctx, cpu), per_cpu(softirq_ctx, cpu));
}
+#ifndef CONFIG_PREEMPT_RT_FULL
asmlinkage void do_softirq(void)
{
unsigned long flags;
@@ -179,6 +180,7 @@
local_irq_restore(flags);
}
+#endif
bool handle_irq(unsigned irq, struct pt_regs *regs)
{
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index d04d3ecd..831f247 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -88,7 +88,7 @@
return true;
}
-
+#ifndef CONFIG_PREEMPT_RT_FULL
extern void call_softirq(void);
asmlinkage void do_softirq(void)
@@ -108,3 +108,4 @@
}
local_irq_restore(flags);
}
+#endif
diff --git a/arch/x86/kernel/irq_work.c b/arch/x86/kernel/irq_work.c
index 1de84e3..15d741d 100644
--- a/arch/x86/kernel/irq_work.c
+++ b/arch/x86/kernel/irq_work.c
@@ -41,7 +41,7 @@
void arch_irq_work_raise(void)
{
#ifdef CONFIG_X86_LOCAL_APIC
- if (!cpu_has_apic)
+ if (!arch_irq_work_has_interrupt())
return;
apic->send_IPI_self(IRQ_WORK_VECTOR);
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index e725933..7e64068 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -35,6 +35,7 @@
#include <linux/slab.h>
#include <linux/kprobes.h>
#include <linux/debugfs.h>
+#include <linux/wait-simple.h>
#include <asm/timer.h>
#include <asm/cpu.h>
#include <asm/traps.h>
@@ -90,14 +91,14 @@
struct kvm_task_sleep_node {
struct hlist_node link;
- wait_queue_head_t wq;
+ struct swait_head wq;
u32 token;
int cpu;
bool halted;
};
static struct kvm_task_sleep_head {
- spinlock_t lock;
+ raw_spinlock_t lock;
struct hlist_head list;
} async_pf_sleepers[KVM_TASK_SLEEP_HASHSIZE];
@@ -121,17 +122,17 @@
u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
struct kvm_task_sleep_node n, *e;
- DEFINE_WAIT(wait);
+ DEFINE_SWAITER(wait);
rcu_irq_enter();
- spin_lock(&b->lock);
+ raw_spin_lock(&b->lock);
e = _find_apf_task(b, token);
if (e) {
/* dummy entry exist -> wake up was delivered ahead of PF */
hlist_del(&e->link);
kfree(e);
- spin_unlock(&b->lock);
+ raw_spin_unlock(&b->lock);
rcu_irq_exit();
return;
@@ -140,13 +141,13 @@
n.token = token;
n.cpu = smp_processor_id();
n.halted = is_idle_task(current) || preempt_count() > 1;
- init_waitqueue_head(&n.wq);
+ init_swait_head(&n.wq);
hlist_add_head(&n.link, &b->list);
- spin_unlock(&b->lock);
+ raw_spin_unlock(&b->lock);
for (;;) {
if (!n.halted)
- prepare_to_wait(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
+ swait_prepare(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
if (hlist_unhashed(&n.link))
break;
@@ -165,7 +166,7 @@
}
}
if (!n.halted)
- finish_wait(&n.wq, &wait);
+ swait_finish(&n.wq, &wait);
rcu_irq_exit();
return;
@@ -177,8 +178,8 @@
hlist_del_init(&n->link);
if (n->halted)
smp_send_reschedule(n->cpu);
- else if (waitqueue_active(&n->wq))
- wake_up(&n->wq);
+ else if (swaitqueue_active(&n->wq))
+ swait_wake(&n->wq);
}
static void apf_task_wake_all(void)
@@ -188,14 +189,14 @@
for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++) {
struct hlist_node *p, *next;
struct kvm_task_sleep_head *b = &async_pf_sleepers[i];
- spin_lock(&b->lock);
+ raw_spin_lock(&b->lock);
hlist_for_each_safe(p, next, &b->list) {
struct kvm_task_sleep_node *n =
hlist_entry(p, typeof(*n), link);
if (n->cpu == smp_processor_id())
apf_task_wake_one(n);
}
- spin_unlock(&b->lock);
+ raw_spin_unlock(&b->lock);
}
}
@@ -211,7 +212,7 @@
}
again:
- spin_lock(&b->lock);
+ raw_spin_lock(&b->lock);
n = _find_apf_task(b, token);
if (!n) {
/*
@@ -224,17 +225,17 @@
* Allocation failed! Busy wait while other cpu
* handles async PF.
*/
- spin_unlock(&b->lock);
+ raw_spin_unlock(&b->lock);
cpu_relax();
goto again;
}
n->token = token;
n->cpu = smp_processor_id();
- init_waitqueue_head(&n->wq);
+ init_swait_head(&n->wq);
hlist_add_head(&n->link, &b->list);
} else
apf_task_wake_one(n);
- spin_unlock(&b->lock);
+ raw_spin_unlock(&b->lock);
return;
}
EXPORT_SYMBOL_GPL(kvm_async_pf_task_wake);
@@ -484,7 +485,7 @@
paravirt_ops_setup();
register_reboot_notifier(&kvm_pv_reboot_nb);
for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++)
- spin_lock_init(&async_pf_sleepers[i].lock);
+ raw_spin_lock_init(&async_pf_sleepers[i].lock);
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF))
x86_init.irqs.trap_init = kvm_apf_trap_init;
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 884f98f..6ce0537 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -36,6 +36,7 @@
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/kdebug.h>
+#include <linux/highmem.h>
#include <asm/pgtable.h>
#include <asm/ldt.h>
@@ -219,6 +220,35 @@
}
EXPORT_SYMBOL_GPL(start_thread);
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p)
+{
+ int i;
+
+ /*
+ * Clear @prev's kmap_atomic mappings
+ */
+ for (i = 0; i < prev_p->kmap_idx; i++) {
+ int idx = i + KM_TYPE_NR * smp_processor_id();
+ pte_t *ptep = kmap_pte - idx;
+
+ kpte_clear_flush(ptep, __fix_to_virt(FIX_KMAP_BEGIN + idx));
+ }
+ /*
+ * Restore @next_p's kmap_atomic mappings
+ */
+ for (i = 0; i < next_p->kmap_idx; i++) {
+ int idx = i + KM_TYPE_NR * smp_processor_id();
+
+ if (!pte_none(next_p->kmap_pte[i]))
+ set_pte(kmap_pte - idx, next_p->kmap_pte[i]);
+ }
+}
+#else
+static inline void
+switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { }
+#endif
+
/*
* switch_to(x,y) should switch tasks from x to y.
@@ -298,6 +328,8 @@
task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT))
__switch_to_xtra(prev_p, next_p, tss);
+ switch_kmaps(prev_p, next_p);
+
/*
* Leave lazy mode, flushing any hypercalls made here.
* This must be done before restoring TLS segments so
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 5d3e601..56d6113 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -747,6 +747,14 @@
mce_notify_process();
#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+ if (unlikely(current->forced_info.si_signo)) {
+ struct task_struct *t = current;
+ force_sig_info(t->forced_info.si_signo, &t->forced_info, t);
+ t->forced_info.si_signo = 0;
+ }
+#endif
+
if (thread_info_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 88f3d3b..d249814 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -86,9 +86,21 @@
local_irq_enable();
}
-static inline void preempt_conditional_sti(struct pt_regs *regs)
+static inline void conditional_sti_ist(struct pt_regs *regs)
{
+#ifdef CONFIG_X86_64
+ /*
+ * X86_64 uses a per CPU stack on the IST for certain traps
+ * like int3. The task can not be preempted when using one
+ * of these stacks, thus preemption must be disabled, otherwise
+ * the stack can be corrupted if the task is scheduled out,
+ * and another task comes in and uses this stack.
+ *
+ * On x86_32 the task keeps its own stack and it is OK if the
+ * task schedules out.
+ */
inc_preempt_count();
+#endif
if (regs->flags & X86_EFLAGS_IF)
local_irq_enable();
}
@@ -99,11 +111,13 @@
local_irq_disable();
}
-static inline void preempt_conditional_cli(struct pt_regs *regs)
+static inline void conditional_cli_ist(struct pt_regs *regs)
{
if (regs->flags & X86_EFLAGS_IF)
local_irq_disable();
+#ifdef CONFIG_X86_64
dec_preempt_count();
+#endif
}
static int __kprobes
@@ -355,9 +369,9 @@
* as we may switch to the interrupt stack.
*/
debug_stack_usage_inc();
- preempt_conditional_sti(regs);
+ conditional_sti_ist(regs);
do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);
- preempt_conditional_cli(regs);
+ conditional_cli_ist(regs);
debug_stack_usage_dec();
exit:
exception_exit(prev_state);
@@ -492,12 +506,12 @@
debug_stack_usage_inc();
/* It's safe to allow irq's after DR6 has been saved */
- preempt_conditional_sti(regs);
+ conditional_sti_ist(regs);
if (regs->flags & X86_VM_MASK) {
handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code,
X86_TRAP_DB);
- preempt_conditional_cli(regs);
+ conditional_cli_ist(regs);
debug_stack_usage_dec();
goto exit;
}
@@ -517,7 +531,7 @@
si_code = get_si_code(tsk->thread.debugreg6);
if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
send_sigtrap(tsk, regs, error_code, si_code);
- preempt_conditional_cli(regs);
+ conditional_cli_ist(regs);
debug_stack_usage_dec();
exit:
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 33d4795..bd01fe7 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1010,8 +1010,38 @@
apic->divide_count);
}
+
+static enum hrtimer_restart apic_timer_fn(struct hrtimer *data);
+
+static void apic_timer_expired(struct hrtimer *data)
+{
+ int ret, i = 0;
+ enum hrtimer_restart r;
+ struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
+
+ r = apic_timer_fn(data);
+
+ if (r == HRTIMER_RESTART) {
+ do {
+ ret = hrtimer_start_expires(data, HRTIMER_MODE_ABS);
+ if (ret == -ETIME)
+ hrtimer_add_expires_ns(&ktimer->timer,
+ ktimer->period);
+ i++;
+ } while (ret == -ETIME && i < 10);
+
+ if (ret == -ETIME) {
+ printk_once(KERN_ERR "%s: failed to reprogram timer\n",
+ __func__);
+ WARN_ON_ONCE(1);
+ }
+ }
+}
+
+
static void start_apic_timer(struct kvm_lapic *apic)
{
+ int ret;
ktime_t now;
atomic_set(&apic->lapic_timer.pending, 0);
@@ -1041,9 +1071,11 @@
}
}
- hrtimer_start(&apic->lapic_timer.timer,
+ ret = hrtimer_start(&apic->lapic_timer.timer,
ktime_add_ns(now, apic->lapic_timer.period),
HRTIMER_MODE_ABS);
+ if (ret == -ETIME)
+ apic_timer_expired(&apic->lapic_timer.timer);
apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016"
PRIx64 ", "
@@ -1073,8 +1105,10 @@
ns = (tscdeadline - guest_tsc) * 1000000ULL;
do_div(ns, this_tsc_khz);
}
- hrtimer_start(&apic->lapic_timer.timer,
+ ret = hrtimer_start(&apic->lapic_timer.timer,
ktime_add_ns(now, ns), HRTIMER_MODE_ABS);
+ if (ret == -ETIME)
+ apic_timer_expired(&apic->lapic_timer.timer);
local_irq_restore(flags);
}
@@ -1512,7 +1546,7 @@
struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
struct kvm_lapic *apic = container_of(ktimer, struct kvm_lapic, lapic_timer);
struct kvm_vcpu *vcpu = apic->vcpu;
- wait_queue_head_t *q = &vcpu->wq;
+ struct swait_head *q = &vcpu->wq;
/*
* There is a race window between reading and incrementing, but we do
@@ -1526,8 +1560,8 @@
kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
}
- if (waitqueue_active(q))
- wake_up_interruptible(q);
+ if (swaitqueue_active(q))
+ swait_wake_interruptible(q);
if (lapic_is_periodic(apic)) {
hrtimer_add_expires_ns(&ktimer->timer, ktimer->period);
@@ -1560,6 +1594,7 @@
hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
HRTIMER_MODE_ABS);
apic->lapic_timer.timer.function = apic_timer_fn;
+ apic->lapic_timer.timer.irqsafe = 1;
/*
* APIC is created enabled. This will prevent kvm_lapic_set_base from
@@ -1673,7 +1708,8 @@
timer = &vcpu->arch.apic->lapic_timer.timer;
if (hrtimer_cancel(timer))
- hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
+ if (hrtimer_start_expires(timer, HRTIMER_MODE_ABS) == -ETIME)
+ apic_timer_expired(timer);
}
/*
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 69e7b0b..0fe2c26 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5540,6 +5540,13 @@
goto out;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
+ printk(KERN_ERR "RT requires X86_FEATURE_CONSTANT_TSC\n");
+ return -EOPNOTSUPP;
+ }
+#endif
+
r = kvm_mmu_module_init();
if (r)
goto out_free_percpu;
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 43df028..3049fb9 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1093,7 +1093,7 @@
* If we're in an interrupt, have no user context or are running
* in an atomic region then we must not take the fault:
*/
- if (unlikely(in_atomic() || !mm)) {
+ if (unlikely(!mm || pagefault_disabled())) {
bad_area_nosemaphore(regs, error_code, address);
return;
}
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 4500142..7f96844 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -32,6 +32,7 @@
*/
void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
+ pte_t pte = mk_pte(page, prot);
unsigned long vaddr;
int idx, type;
@@ -45,7 +46,10 @@
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
BUG_ON(!pte_none(*(kmap_pte-idx)));
- set_pte(kmap_pte-idx, mk_pte(page, prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = pte;
+#endif
+ set_pte(kmap_pte-idx, pte);
arch_flush_lazy_mmu_mode();
return (void *)vaddr;
@@ -88,6 +92,9 @@
* is a bad idea also, in case the page changes cacheability
* attributes or becomes a protected page in a hypervisor.
*/
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = __pte(0);
+#endif
kpte_clear_flush(kmap_pte-idx, vaddr);
kmap_atomic_idx_pop();
arch_flush_lazy_mmu_mode();
diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c
index 7b179b49..62377d6 100644
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -56,6 +56,7 @@
void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
{
+ pte_t pte = pfn_pte(pfn, prot);
unsigned long vaddr;
int idx, type;
@@ -64,7 +65,12 @@
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
+ WARN_ON(!pte_none(*(kmap_pte - idx)));
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = pte;
+#endif
+ set_pte(kmap_pte - idx, pte);
arch_flush_lazy_mmu_mode();
return (void *)vaddr;
@@ -110,6 +116,9 @@
* is a bad idea also, in case the page changes cacheability
* attributes or becomes a protected page in a hypervisor.
*/
+#ifdef CONFIG_PREEMPT_RT_FULL
+ current->kmap_pte[type] = __pte(0);
+#endif
kpte_clear_flush(kmap_pte-idx, vaddr);
kmap_atomic_idx_pop();
}
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 0fcd960..0fd8d4e 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -210,7 +210,15 @@
int in_flags, struct page **pages)
{
unsigned int i, level;
+#ifdef CONFIG_PREEMPT
+ /*
+ * Avoid wbinvd() because it causes latencies on all CPUs,
+ * regardless of any CPU isolation that may be in effect.
+ */
+ unsigned long do_wbinvd = 0;
+#else
unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */
+#endif
BUG_ON(irqs_disabled());
diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
index a6b5aff..e9e67512 100644
--- a/arch/x86/platform/uv/tlb_uv.c
+++ b/arch/x86/platform/uv/tlb_uv.c
@@ -695,9 +695,9 @@
quiesce_local_uvhub(hmaster);
- spin_lock(&hmaster->queue_lock);
+ raw_spin_lock(&hmaster->queue_lock);
reset_with_ipi(&bau_desc->distribution, bcp);
- spin_unlock(&hmaster->queue_lock);
+ raw_spin_unlock(&hmaster->queue_lock);
end_uvhub_quiesce(hmaster);
@@ -717,9 +717,9 @@
quiesce_local_uvhub(hmaster);
- spin_lock(&hmaster->queue_lock);
+ raw_spin_lock(&hmaster->queue_lock);
reset_with_ipi(&bau_desc->distribution, bcp);
- spin_unlock(&hmaster->queue_lock);
+ raw_spin_unlock(&hmaster->queue_lock);
end_uvhub_quiesce(hmaster);
@@ -740,7 +740,7 @@
cycles_t tm1;
hmaster = bcp->uvhub_master;
- spin_lock(&hmaster->disable_lock);
+ raw_spin_lock(&hmaster->disable_lock);
if (!bcp->baudisabled) {
stat->s_bau_disabled++;
tm1 = get_cycles();
@@ -753,7 +753,7 @@
}
}
}
- spin_unlock(&hmaster->disable_lock);
+ raw_spin_unlock(&hmaster->disable_lock);
}
static void count_max_concurr(int stat, struct bau_control *bcp,
@@ -816,7 +816,7 @@
*/
static void uv1_throttle(struct bau_control *hmaster, struct ptc_stats *stat)
{
- spinlock_t *lock = &hmaster->uvhub_lock;
+ raw_spinlock_t *lock = &hmaster->uvhub_lock;
atomic_t *v;
v = &hmaster->active_descriptor_count;
@@ -948,7 +948,7 @@
struct bau_control *hmaster;
hmaster = bcp->uvhub_master;
- spin_lock(&hmaster->disable_lock);
+ raw_spin_lock(&hmaster->disable_lock);
if (bcp->baudisabled && (get_cycles() >= bcp->set_bau_on_time)) {
stat->s_bau_reenabled++;
for_each_present_cpu(tcpu) {
@@ -960,10 +960,10 @@
tbcp->period_giveups = 0;
}
}
- spin_unlock(&hmaster->disable_lock);
+ raw_spin_unlock(&hmaster->disable_lock);
return 0;
}
- spin_unlock(&hmaster->disable_lock);
+ raw_spin_unlock(&hmaster->disable_lock);
return -1;
}
@@ -1885,9 +1885,9 @@
bcp->cong_reps = congested_reps;
bcp->disabled_period = sec_2_cycles(disabled_period);
bcp->giveup_limit = giveup_limit;
- spin_lock_init(&bcp->queue_lock);
- spin_lock_init(&bcp->uvhub_lock);
- spin_lock_init(&bcp->disable_lock);
+ raw_spin_lock_init(&bcp->queue_lock);
+ raw_spin_lock_init(&bcp->uvhub_lock);
+ raw_spin_lock_init(&bcp->disable_lock);
}
}
diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
index 5c86786..c039afa 100644
--- a/arch/x86/platform/uv/uv_time.c
+++ b/arch/x86/platform/uv/uv_time.c
@@ -58,7 +58,7 @@
/* There is one of these allocated per node */
struct uv_rtc_timer_head {
- spinlock_t lock;
+ raw_spinlock_t lock;
/* next cpu waiting for timer, local node relative: */
int next_cpu;
/* number of cpus on this node: */
@@ -178,7 +178,7 @@
uv_rtc_deallocate_timers();
return -ENOMEM;
}
- spin_lock_init(&head->lock);
+ raw_spin_lock_init(&head->lock);
head->ncpus = uv_blade_nr_possible_cpus(bid);
head->next_cpu = -1;
blade_info[bid] = head;
@@ -232,7 +232,7 @@
unsigned long flags;
int next_cpu;
- spin_lock_irqsave(&head->lock, flags);
+ raw_spin_lock_irqsave(&head->lock, flags);
next_cpu = head->next_cpu;
*t = expires;
@@ -244,12 +244,12 @@
if (uv_setup_intr(cpu, expires)) {
*t = ULLONG_MAX;
uv_rtc_find_next_timer(head, pnode);
- spin_unlock_irqrestore(&head->lock, flags);
+ raw_spin_unlock_irqrestore(&head->lock, flags);
return -ETIME;
}
}
- spin_unlock_irqrestore(&head->lock, flags);
+ raw_spin_unlock_irqrestore(&head->lock, flags);
return 0;
}
@@ -268,7 +268,7 @@
unsigned long flags;
int rc = 0;
- spin_lock_irqsave(&head->lock, flags);
+ raw_spin_lock_irqsave(&head->lock, flags);
if ((head->next_cpu == bcpu && uv_read_rtc(NULL) >= *t) || force)
rc = 1;
@@ -280,7 +280,7 @@
uv_rtc_find_next_timer(head, pnode);
}
- spin_unlock_irqrestore(&head->lock, flags);
+ raw_spin_unlock_irqrestore(&head->lock, flags);
return rc;
}
@@ -300,13 +300,18 @@
static cycle_t uv_read_rtc(struct clocksource *cs)
{
unsigned long offset;
+ cycle_t cycles;
+ preempt_disable();
if (uv_get_min_hub_revision_id() == 1)
offset = 0;
else
offset = (uv_blade_processor_id() * L1_CACHE_BYTES) % PAGE_SIZE;
- return (cycle_t)uv_read_local_mmr(UVH_RTC | offset);
+ cycles = (cycle_t)uv_read_local_mmr(UVH_RTC | offset);
+ preempt_enable();
+
+ return cycles;
}
/*
diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild
index 1b98264..981ae14 100644
--- a/arch/xtensa/include/asm/Kbuild
+++ b/arch/xtensa/include/asm/Kbuild
@@ -12,6 +12,7 @@
generic-y += hardirq.h
generic-y += ioctl.h
generic-y += irq_regs.h
+generic-y += irq_work.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += kvm_para.h
diff --git a/arch/xtensa/mm/fault.c b/arch/xtensa/mm/fault.c
index 3827833..20d6ff6 100644
--- a/arch/xtensa/mm/fault.c
+++ b/arch/xtensa/mm/fault.c
@@ -57,7 +57,7 @@
/* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm) {
+ if (!mm || pagefault_disabled()) {
bad_page_fault(regs, address, SIGSEGV);
return;
}
diff --git a/block/blk-core.c b/block/blk-core.c
index 876c2ba..21a127c 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -232,7 +232,7 @@
**/
void blk_start_queue(struct request_queue *q)
{
- WARN_ON(!irqs_disabled());
+ WARN_ON_NONRT(!irqs_disabled());
queue_flag_clear(QUEUE_FLAG_STOPPED, q);
__blk_run_queue(q);
@@ -2918,7 +2918,7 @@
blk_run_queue_async(q);
else
__blk_run_queue(q);
- spin_unlock(q->queue_lock);
+ spin_unlock_irq(q->queue_lock);
}
static void flush_plug_callbacks(struct blk_plug *plug, bool from_schedule)
@@ -2966,7 +2966,6 @@
void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
{
struct request_queue *q;
- unsigned long flags;
struct request *rq;
LIST_HEAD(list);
unsigned int depth;
@@ -2984,11 +2983,6 @@
q = NULL;
depth = 0;
- /*
- * Save and disable interrupts here, to avoid doing it for every
- * queue lock we have to take.
- */
- local_irq_save(flags);
while (!list_empty(&list)) {
rq = list_entry_rq(list.next);
list_del_init(&rq->queuelist);
@@ -3001,7 +2995,7 @@
queue_unplugged(q, depth, from_schedule);
q = rq->q;
depth = 0;
- spin_lock(q->queue_lock);
+ spin_lock_irq(q->queue_lock);
}
/*
@@ -3028,8 +3022,6 @@
*/
if (q)
queue_unplugged(q, depth, from_schedule);
-
- local_irq_restore(flags);
}
void blk_finish_plug(struct blk_plug *plug)
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 46cd7bd..899d3e4 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -8,6 +8,7 @@
#include <linux/blkdev.h>
#include <linux/bootmem.h> /* for max_pfn/max_low_pfn */
#include <linux/slab.h>
+#include <linux/delay.h>
#include "blk.h"
@@ -110,7 +111,7 @@
spin_unlock(q->queue_lock);
} else {
spin_unlock_irqrestore(&ioc->lock, flags);
- cpu_relax();
+ cpu_chill();
spin_lock_irqsave_nested(&ioc->lock, flags, 1);
}
}
@@ -188,7 +189,7 @@
spin_unlock(icq->q->queue_lock);
} else {
spin_unlock_irqrestore(&ioc->lock, flags);
- cpu_relax();
+ cpu_chill();
goto retry;
}
}
diff --git a/block/blk-iopoll.c b/block/blk-iopoll.c
index 4b8d9b54..15b4f08 100644
--- a/block/blk-iopoll.c
+++ b/block/blk-iopoll.c
@@ -38,6 +38,7 @@
list_add_tail(&iop->list, &__get_cpu_var(blk_cpu_iopoll));
__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
EXPORT_SYMBOL(blk_iopoll_sched);
@@ -135,6 +136,7 @@
__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
}
/**
@@ -204,6 +206,7 @@
&__get_cpu_var(blk_cpu_iopoll));
__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
}
return NOTIFY_OK;
diff --git a/block/blk-softirq.c b/block/blk-softirq.c
index ec9e606..814b3db 100644
--- a/block/blk-softirq.c
+++ b/block/blk-softirq.c
@@ -51,6 +51,7 @@
raise_softirq_irqoff(BLOCK_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
/*
@@ -93,6 +94,7 @@
&__get_cpu_var(blk_cpu_done));
raise_softirq_irqoff(BLOCK_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
}
return NOTIFY_OK;
@@ -150,6 +152,7 @@
goto do_local;
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
/**
diff --git a/crypto/algapi.c b/crypto/algapi.c
index 8ea7a5d..d98a5f0 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -685,13 +685,13 @@
int crypto_register_notifier(struct notifier_block *nb)
{
- return blocking_notifier_chain_register(&crypto_chain, nb);
+ return srcu_notifier_chain_register(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_register_notifier);
int crypto_unregister_notifier(struct notifier_block *nb)
{
- return blocking_notifier_chain_unregister(&crypto_chain, nb);
+ return srcu_notifier_chain_unregister(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
diff --git a/crypto/api.c b/crypto/api.c
index 7db2e89..25a77b2 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -31,7 +31,7 @@
DECLARE_RWSEM(crypto_alg_sem);
EXPORT_SYMBOL_GPL(crypto_alg_sem);
-BLOCKING_NOTIFIER_HEAD(crypto_chain);
+SRCU_NOTIFIER_HEAD(crypto_chain);
EXPORT_SYMBOL_GPL(crypto_chain);
static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
@@ -236,10 +236,10 @@
{
int ok;
- ok = blocking_notifier_call_chain(&crypto_chain, val, v);
+ ok = srcu_notifier_call_chain(&crypto_chain, val, v);
if (ok == NOTIFY_DONE) {
request_module("cryptomgr");
- ok = blocking_notifier_call_chain(&crypto_chain, val, v);
+ ok = srcu_notifier_call_chain(&crypto_chain, val, v);
}
return ok;
diff --git a/crypto/internal.h b/crypto/internal.h
index bd39bfc..a5db167 100644
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -48,7 +48,7 @@
extern struct list_head crypto_alg_list;
extern struct rw_semaphore crypto_alg_sem;
-extern struct blocking_notifier_head crypto_chain;
+extern struct srcu_notifier_head crypto_chain;
#ifdef CONFIG_PROC_FS
void __init crypto_init_proc(void);
@@ -142,7 +142,7 @@
static inline void crypto_notify(unsigned long val, void *v)
{
- blocking_notifier_call_chain(&crypto_chain, val, v);
+ srcu_notifier_call_chain(&crypto_chain, val, v);
}
#endif /* _CRYPTO_INTERNAL_H */
diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index 90e846f..411f68d 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -235,7 +235,7 @@
* interrupt level
*/
ACPI_EXTERN acpi_spinlock acpi_gbl_gpe_lock; /* For GPE data structs and registers */
-ACPI_EXTERN acpi_spinlock acpi_gbl_hardware_lock; /* For ACPI H/W except GPE registers */
+ACPI_EXTERN acpi_raw_spinlock acpi_gbl_hardware_lock; /* For ACPI H/W except GPE registers */
ACPI_EXTERN acpi_spinlock acpi_gbl_reference_count_lock;
/* Mutex for _OSI support */
diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c
index 8d2e866..221c567 100644
--- a/drivers/acpi/acpica/hwregs.c
+++ b/drivers/acpi/acpica/hwregs.c
@@ -269,14 +269,14 @@
ACPI_BITMASK_ALL_FIXED_STATUS,
ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address)));
- lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
+ raw_spin_lock_irqsave(acpi_gbl_hardware_lock, lock_flags);
/* Clear the fixed events in PM1 A/B */
status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
ACPI_BITMASK_ALL_FIXED_STATUS);
- acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
+ raw_spin_unlock_irqrestore(acpi_gbl_hardware_lock, lock_flags);
if (ACPI_FAILURE(status))
goto exit;
diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c
index 3f78811..d111ee1 100644
--- a/drivers/acpi/acpica/hwxface.c
+++ b/drivers/acpi/acpica/hwxface.c
@@ -365,7 +365,7 @@
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
- lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
+ raw_spin_lock_irqsave(acpi_gbl_hardware_lock, lock_flags);
/*
* At this point, we know that the parent register is one of the
@@ -426,7 +426,7 @@
unlock_and_exit:
- acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
+ raw_spin_unlock_irqrestore(acpi_gbl_hardware_lock, lock_flags);
return_ACPI_STATUS(status);
}
diff --git a/drivers/acpi/acpica/utmutex.c b/drivers/acpi/acpica/utmutex.c
index 08c3232..2f4ed8b 100644
--- a/drivers/acpi/acpica/utmutex.c
+++ b/drivers/acpi/acpica/utmutex.c
@@ -88,7 +88,7 @@
return_ACPI_STATUS (status);
}
- status = acpi_os_create_lock (&acpi_gbl_hardware_lock);
+ status = acpi_os_create_raw_lock (&acpi_gbl_hardware_lock);
if (ACPI_FAILURE (status)) {
return_ACPI_STATUS (status);
}
@@ -141,7 +141,7 @@
/* Delete the spinlocks */
acpi_os_delete_lock(acpi_gbl_gpe_lock);
- acpi_os_delete_lock(acpi_gbl_hardware_lock);
+ acpi_os_delete_raw_lock(acpi_gbl_hardware_lock);
acpi_os_delete_lock(acpi_gbl_reference_count_lock);
/* Delete the reader/writer lock */
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 96e5ed1..872a056 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -678,9 +678,9 @@
unsigned long flags;
unsigned int consumed;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
consumed = ata_sff_data_xfer32(dev, buf, buflen, rw);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return consumed;
}
@@ -719,7 +719,7 @@
unsigned long flags;
/* FIXME: use a bounce buffer */
- local_irq_save(flags);
+ local_irq_save_nort(flags);
buf = kmap_atomic(page);
/* do the actual data transfer */
@@ -727,7 +727,7 @@
do_write);
kunmap_atomic(buf);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
} else {
buf = page_address(page);
ap->ops->sff_data_xfer(qc->dev, buf + offset, qc->sect_size,
@@ -864,7 +864,7 @@
unsigned long flags;
/* FIXME: use bounce buffer */
- local_irq_save(flags);
+ local_irq_save_nort(flags);
buf = kmap_atomic(page);
/* do the actual data transfer */
@@ -872,7 +872,7 @@
count, rw);
kunmap_atomic(buf);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
} else {
buf = page_address(page);
consumed = ap->ops->sff_data_xfer(dev, buf + offset,
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 85e771c..184ef8a 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -673,9 +673,12 @@
preempt_disable();
/* if over the trickle threshold, use only 1 in 4096 samples */
if (input_pool.entropy_count > trickle_thresh &&
- ((__this_cpu_inc_return(trickle_count) - 1) & 0xfff))
- goto out;
+ ((__this_cpu_inc_return(trickle_count) - 1) & 0xfff)) {
+ preempt_enable();
+ return;
+ }
+ preempt_enable();
sample.jiffies = jiffies;
sample.cycles = random_get_entropy();
sample.num = num;
@@ -716,8 +719,6 @@
credit_entropy_bits(&input_pool,
min_t(int, fls(delta>>1), 11));
}
-out:
- preempt_enable();
}
void add_input_randomness(unsigned int type, unsigned int code,
@@ -738,18 +739,16 @@
static DEFINE_PER_CPU(struct fast_pool, irq_randomness);
-void add_interrupt_randomness(int irq, int irq_flags)
+void add_interrupt_randomness(int irq, int irq_flags, __u64 ip)
{
struct entropy_store *r;
struct fast_pool *fast_pool = &__get_cpu_var(irq_randomness);
- struct pt_regs *regs = get_irq_regs();
unsigned long now = jiffies;
__u32 input[4], cycles = random_get_entropy();
input[0] = cycles ^ jiffies;
input[1] = irq;
- if (regs) {
- __u64 ip = instruction_pointer(regs);
+ if (ip) {
input[2] = ip;
input[3] = ip >> 32;
}
@@ -763,7 +762,11 @@
fast_pool->last = now;
r = nonblocking_pool.initialized ? &input_pool : &nonblocking_pool;
+#ifndef CONFIG_PREEMPT_RT_FULL
__mix_pool_bytes(r, &fast_pool->pool, sizeof(fast_pool->pool), NULL);
+#else
+ mix_pool_bytes(r, &fast_pool->pool, sizeof(fast_pool->pool), NULL);
+#endif
/*
* If we don't have a valid cycle counter, and we see
* back-to-back timer interrupts, then skip giving credit for
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 8a61872..a00dfaf 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -23,8 +23,7 @@
* this 32 bit free-running counter. the second channel is not used.
*
* - The third channel may be used to provide a 16-bit clockevent
- * source, used in either periodic or oneshot mode. This runs
- * at 32 KiHZ, and can handle delays of up to two seconds.
+ * source, used in either periodic or oneshot mode.
*
* A boot clocksource and clockevent source are also currently needed,
* unless the relevant platforms (ARM/AT91, AVR32/AT32) are changed so
@@ -74,6 +73,7 @@
struct tc_clkevt_device {
struct clock_event_device clkevt;
struct clk *clk;
+ u32 freq;
void __iomem *regs;
};
@@ -82,13 +82,6 @@
return container_of(clkevt, struct tc_clkevt_device, clkevt);
}
-/* For now, we always use the 32K clock ... this optimizes for NO_HZ,
- * because using one of the divided clocks would usually mean the
- * tick rate can never be less than several dozen Hz (vs 0.5 Hz).
- *
- * A divided clock could be good for high resolution timers, since
- * 30.5 usec resolution can seem "low".
- */
static u32 timer_clock;
static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
@@ -111,11 +104,12 @@
case CLOCK_EVT_MODE_PERIODIC:
clk_enable(tcd->clk);
- /* slow clock, count up to RC, then irq and restart */
+ /* count up to RC, then irq and restart */
__raw_writel(timer_clock
| ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
regs + ATMEL_TC_REG(2, CMR));
- __raw_writel((32768 + HZ/2) / HZ, tcaddr + ATMEL_TC_REG(2, RC));
+ __raw_writel((tcd->freq + HZ/2)/HZ,
+ tcaddr + ATMEL_TC_REG(2, RC));
/* Enable clock and interrupts on RC compare */
__raw_writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER));
@@ -128,7 +122,7 @@
case CLOCK_EVT_MODE_ONESHOT:
clk_enable(tcd->clk);
- /* slow clock, count up to RC, then irq and stop */
+ /* count up to RC, then irq and stop */
__raw_writel(timer_clock | ATMEL_TC_CPCSTOP
| ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
regs + ATMEL_TC_REG(2, CMR));
@@ -157,8 +151,12 @@
.name = "tc_clkevt",
.features = CLOCK_EVT_FEAT_PERIODIC
| CLOCK_EVT_FEAT_ONESHOT,
+#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
/* Should be lower than at91rm9200's system timer */
.rating = 125,
+#else
+ .rating = 200,
+#endif
.set_next_event = tc_next_event,
.set_mode = tc_mode,
},
@@ -184,8 +182,9 @@
.handler = ch2_irq,
};
-static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static void __init setup_clkevents(struct atmel_tc *tc, int divisor_idx)
{
+ unsigned divisor = atmel_tc_divisors[divisor_idx];
struct clk *t2_clk = tc->clk[2];
int irq = tc->irq[2];
@@ -193,11 +192,15 @@
clkevt.clk = t2_clk;
tc_irqaction.dev_id = &clkevt;
- timer_clock = clk32k_divisor_idx;
+ timer_clock = divisor_idx;
+ if (!divisor)
+ clkevt.freq = 32768;
+ else
+ clkevt.freq = clk_get_rate(t2_clk) / divisor;
clkevt.clkevt.cpumask = cpumask_of(0);
- clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
+ clockevents_config_and_register(&clkevt.clkevt, clkevt.freq, 1, 0xffff);
setup_irq(irq, &tc_irqaction);
}
@@ -322,8 +325,11 @@
clocksource_register_hz(&clksrc, divided_rate);
/* channel 2: periodic and oneshot timer support */
+#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
setup_clkevents(tc, clk32k_divisor_idx);
-
+#else
+ setup_clkevents(tc, best_divisor_idx);
+#endif
return 0;
}
arch_initcall(tcb_clksrc_init);
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 6237f68..a1442a0 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -90,12 +90,6 @@
unlock_policy_rwsem(read, cpu);
unlock_policy_rwsem(write, cpu);
-/*
- * rwsem to guarantee that cpufreq driver module doesn't unload during critical
- * sections
- */
-static DECLARE_RWSEM(cpufreq_rwsem);
-
/* internal prototypes */
static int __cpufreq_governor(struct cpufreq_policy *policy,
unsigned int event);
@@ -191,9 +185,6 @@
if (cpufreq_disabled() || (cpu >= nr_cpu_ids))
return NULL;
- if (!down_read_trylock(&cpufreq_rwsem))
- return NULL;
-
/* get the cpufreq driver */
read_lock_irqsave(&cpufreq_driver_lock, flags);
@@ -206,9 +197,6 @@
read_unlock_irqrestore(&cpufreq_driver_lock, flags);
- if (!policy)
- up_read(&cpufreq_rwsem);
-
return policy;
}
EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
@@ -219,7 +207,6 @@
return;
kobject_put(&policy->kobj);
- up_read(&cpufreq_rwsem);
}
EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
@@ -666,13 +653,10 @@
{
struct cpufreq_policy *policy = to_policy(kobj);
struct freq_attr *fattr = to_attr(attr);
- ssize_t ret = -EINVAL;
-
- if (!down_read_trylock(&cpufreq_rwsem))
- goto exit;
+ ssize_t ret;
if (lock_policy_rwsem_read(policy->cpu) < 0)
- goto up_read;
+ return -EINVAL;
if (fattr->show)
ret = fattr->show(policy, buf);
@@ -681,9 +665,6 @@
unlock_policy_rwsem_read(policy->cpu);
-up_read:
- up_read(&cpufreq_rwsem);
-exit:
return ret;
}
@@ -699,11 +680,8 @@
if (!cpu_online(policy->cpu))
goto unlock;
- if (!down_read_trylock(&cpufreq_rwsem))
- goto unlock;
-
if (lock_policy_rwsem_write(policy->cpu) < 0)
- goto up_read;
+ goto unlock;
if (fattr->store)
ret = fattr->store(policy, buf, count);
@@ -712,8 +690,6 @@
unlock_policy_rwsem_write(policy->cpu);
-up_read:
- up_read(&cpufreq_rwsem);
unlock:
put_online_cpus();
@@ -1026,9 +1002,6 @@
}
#endif
- if (!down_read_trylock(&cpufreq_rwsem))
- return 0;
-
#ifdef CONFIG_HOTPLUG_CPU
/* Check if this cpu was hot-unplugged earlier and has siblings */
read_lock_irqsave(&cpufreq_driver_lock, flags);
@@ -1036,7 +1009,6 @@
if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) {
read_unlock_irqrestore(&cpufreq_driver_lock, flags);
ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev);
- up_read(&cpufreq_rwsem);
return ret;
}
}
@@ -1051,8 +1023,9 @@
if (!policy) {
frozen = false;
policy = cpufreq_policy_alloc();
+
if (!policy)
- goto nomem_out;
+ return ret;
}
/*
@@ -1132,7 +1105,6 @@
}
kobject_uevent(&policy->kobj, KOBJ_ADD);
- up_read(&cpufreq_rwsem);
pr_debug("initialization complete\n");
@@ -1152,9 +1124,6 @@
}
cpufreq_policy_free(policy);
-nomem_out:
- up_read(&cpufreq_rwsem);
-
return ret;
}
@@ -1486,9 +1455,6 @@
if (cpufreq_disabled() || !cpufreq_driver)
return -ENOENT;
- if (!down_read_trylock(&cpufreq_rwsem))
- return 0;
-
if (unlikely(lock_policy_rwsem_read(cpu)))
goto out_policy;
@@ -1497,8 +1463,6 @@
unlock_policy_rwsem_read(cpu);
out_policy:
- up_read(&cpufreq_rwsem);
-
return ret_freq;
}
EXPORT_SYMBOL(cpufreq_get);
@@ -2196,16 +2160,17 @@
pr_debug("unregistering driver %s\n", driver->name);
+ /* Protect against concurrent cpu hotplug */
+ get_online_cpus();
subsys_interface_unregister(&cpufreq_interface);
unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
- down_write(&cpufreq_rwsem);
write_lock_irqsave(&cpufreq_driver_lock, flags);
cpufreq_driver = NULL;
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
- up_write(&cpufreq_rwsem);
+ put_online_cpus();
return 0;
}
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 8f4ad0f..9b60daf 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -59,7 +59,7 @@
u32 saved_datain;
u32 level_mask;
u32 toggle_mask;
- spinlock_t lock;
+ raw_spinlock_t lock;
struct gpio_chip chip;
struct clk *dbck;
u32 mod_usage;
@@ -503,19 +503,19 @@
(type & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH)))
return -EINVAL;
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
offset = GPIO_INDEX(bank, gpio);
retval = _set_gpio_triggering(bank, offset, type);
if (!LINE_USED(bank->mod_usage, offset)) {
_enable_gpio_module(bank, offset);
_set_gpio_direction(bank, offset, 1);
} else if (!gpio_is_input(bank, 1 << offset)) {
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return -EINVAL;
}
bank->irq_usage |= 1 << GPIO_INDEX(bank, gpio);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
__irq_set_handler_locked(d->irq, handle_level_irq);
@@ -632,14 +632,14 @@
return -EINVAL;
}
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
if (enable)
bank->context.wake_en |= gpio_bit;
else
bank->context.wake_en &= ~gpio_bit;
writel_relaxed(bank->context.wake_en, bank->base + bank->regs->wkup_en);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
@@ -674,7 +674,7 @@
if (!BANK_USED(bank))
pm_runtime_get_sync(bank->dev);
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
/* Set trigger to none. You need to enable the desired trigger with
* request_irq() or set_irq_type(). Only do this if the IRQ line has
* not already been requested.
@@ -684,7 +684,7 @@
_enable_gpio_module(bank, offset);
}
bank->mod_usage |= 1 << offset;
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
@@ -694,11 +694,11 @@
struct gpio_bank *bank = container_of(chip, struct gpio_bank, chip);
unsigned long flags;
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
bank->mod_usage &= ~(1 << offset);
_disable_gpio_module(bank, offset);
_reset_gpio(bank, bank->chip.base + offset);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
/*
* If this is the last gpio to be freed in the bank,
@@ -796,11 +796,11 @@
unsigned long flags;
unsigned offset = GPIO_INDEX(bank, gpio);
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
bank->irq_usage &= ~(1 << offset);
_disable_gpio_module(bank, offset);
_reset_gpio(bank, gpio);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
/*
* If this is the last IRQ to be freed in the bank,
@@ -824,10 +824,10 @@
unsigned int gpio = irq_to_gpio(bank, d->hwirq);
unsigned long flags;
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
_set_gpio_irqenable(bank, gpio, 0);
_set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), IRQ_TYPE_NONE);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
}
static void gpio_unmask_irq(struct irq_data *d)
@@ -838,7 +838,7 @@
u32 trigger = irqd_get_trigger_type(d);
unsigned long flags;
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
if (trigger)
_set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), trigger);
@@ -850,7 +850,7 @@
}
_set_gpio_irqenable(bank, gpio, 1);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
}
static struct irq_chip gpio_irq_chip = {
@@ -873,9 +873,9 @@
OMAP_MPUIO_GPIO_MASKIT / bank->stride;
unsigned long flags;
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
writel_relaxed(0xffff & ~bank->context.wake_en, mask_reg);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
@@ -888,9 +888,9 @@
OMAP_MPUIO_GPIO_MASKIT / bank->stride;
unsigned long flags;
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
writel_relaxed(bank->context.wake_en, mask_reg);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
@@ -933,9 +933,9 @@
unsigned long flags;
bank = container_of(chip, struct gpio_bank, chip);
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
_set_gpio_direction(bank, offset, 1);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
@@ -960,7 +960,7 @@
int retval = 0;
bank = container_of(chip, struct gpio_bank, chip);
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
if (LINE_USED(bank->irq_usage, offset)) {
retval = -EINVAL;
@@ -971,7 +971,7 @@
_set_gpio_direction(bank, offset, 0);
exit:
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return retval;
}
@@ -983,9 +983,9 @@
bank = container_of(chip, struct gpio_bank, chip);
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
_set_gpio_debounce(bank, offset, debounce);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
@@ -996,9 +996,9 @@
unsigned long flags;
bank = container_of(chip, struct gpio_bank, chip);
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
bank->set_dataout(bank, offset, value);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
}
/*---------------------------------------------------------------------*/
@@ -1210,7 +1210,7 @@
else
bank->set_dataout = _set_gpio_dataout_mask;
- spin_lock_init(&bank->lock);
+ raw_spin_lock_init(&bank->lock);
/* Static mapping, never released */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1267,7 +1267,7 @@
unsigned long flags;
u32 wake_low, wake_hi;
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
/*
* Only edges can generate a wakeup event to the PRCM.
@@ -1320,7 +1320,7 @@
bank->get_context_loss_count(bank->dev);
_gpio_dbck_disable(bank);
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
@@ -1335,7 +1335,7 @@
unsigned long flags;
int c;
- spin_lock_irqsave(&bank->lock, flags);
+ raw_spin_lock_irqsave(&bank->lock, flags);
/*
* On the first resume during the probe, the context has not
@@ -1371,14 +1371,14 @@
if (c != bank->context_loss_count) {
omap_gpio_restore_context(bank);
} else {
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
}
}
if (!bank->workaround_enabled) {
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
@@ -1433,7 +1433,7 @@
}
bank->workaround_enabled = false;
- spin_unlock_irqrestore(&bank->lock, flags);
+ raw_spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index f92da0a..434ea84 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -628,11 +628,6 @@
* code gets preempted or delayed for some reason.
*/
for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
- /* Disable preemption to make it very likely to
- * succeed in the first iteration even on PREEMPT_RT kernel.
- */
- preempt_disable();
-
/* Get system timestamp before query. */
stime = ktime_get();
@@ -644,8 +639,6 @@
if (!drm_timestamp_monotonic)
mono_time_offset = ktime_get_monotonic_offset();
- preempt_enable();
-
/* Return as no-op if scanout query unsupported or failed. */
if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f97d221..b1bfed1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4802,7 +4802,7 @@
if (!mutex_is_locked(mutex))
return false;
-#if defined(CONFIG_SMP) && !defined(CONFIG_DEBUG_MUTEXES)
+#if defined(CONFIG_SMP) && !defined(CONFIG_DEBUG_MUTEXES) && !defined(CONFIG_PREEMPT_RT_BASE)
return mutex->owner == task;
#else
/* Since UP may be pre-empted, we cannot assume that we own the lock */
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index c08287f..d5f6bee 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1129,7 +1129,9 @@
goto err;
}
+#ifndef CONFIG_PREEMPT_RT_BASE
trace_i915_gem_ring_dispatch(ring, intel_ring_get_seqno(ring), flags);
+#endif
i915_gem_execbuffer_move_to_active(&eb->objects, vm, ring);
i915_gem_execbuffer_retire_commands(dev, file, ring, batch_obj);
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 8eaaff8..123dc83 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -879,15 +879,12 @@
u16 mask;
u16 stat;
- spin_lock(&dev->lock);
- mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
+ mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
if (stat & mask)
ret = IRQ_WAKE_THREAD;
- spin_unlock(&dev->lock);
-
return ret;
}
diff --git a/drivers/ide/alim15x3.c b/drivers/ide/alim15x3.c
index 36f76e2..394f142f 100644
--- a/drivers/ide/alim15x3.c
+++ b/drivers/ide/alim15x3.c
@@ -234,7 +234,7 @@
isa_dev = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, NULL);
- local_irq_save(flags);
+ local_irq_save_nort(flags);
if (m5229_revision < 0xC2) {
/*
@@ -325,7 +325,7 @@
}
pci_dev_put(north);
pci_dev_put(isa_dev);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return 0;
}
diff --git a/drivers/ide/hpt366.c b/drivers/ide/hpt366.c
index 696b6c1..0d0a966 100644
--- a/drivers/ide/hpt366.c
+++ b/drivers/ide/hpt366.c
@@ -1241,7 +1241,7 @@
dma_old = inb(base + 2);
- local_irq_save(flags);
+ local_irq_save_nort(flags);
dma_new = dma_old;
pci_read_config_byte(dev, hwif->channel ? 0x4b : 0x43, &masterdma);
@@ -1252,7 +1252,7 @@
if (dma_new != dma_old)
outb(dma_new, base + 2);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
printk(KERN_INFO " %s: BM-DMA at 0x%04lx-0x%04lx\n",
hwif->name, base, base + 7);
diff --git a/drivers/ide/ide-io-std.c b/drivers/ide/ide-io-std.c
index 1976397..4169433 100644
--- a/drivers/ide/ide-io-std.c
+++ b/drivers/ide/ide-io-std.c
@@ -175,7 +175,7 @@
unsigned long uninitialized_var(flags);
if ((io_32bit & 2) && !mmio) {
- local_irq_save(flags);
+ local_irq_save_nort(flags);
ata_vlb_sync(io_ports->nsect_addr);
}
@@ -186,7 +186,7 @@
insl(data_addr, buf, words);
if ((io_32bit & 2) && !mmio)
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
if (((len + 1) & 3) < 2)
return;
@@ -219,7 +219,7 @@
unsigned long uninitialized_var(flags);
if ((io_32bit & 2) && !mmio) {
- local_irq_save(flags);
+ local_irq_save_nort(flags);
ata_vlb_sync(io_ports->nsect_addr);
}
@@ -230,7 +230,7 @@
outsl(data_addr, buf, words);
if ((io_32bit & 2) && !mmio)
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
if (((len + 1) & 3) < 2)
return;
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 177db6d..079ae6b 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -659,7 +659,7 @@
/* disable_irq_nosync ?? */
disable_irq(hwif->irq);
/* local CPU only, as if we were handling an interrupt */
- local_irq_disable();
+ local_irq_disable_nort();
if (hwif->polling) {
startstop = handler(drive);
} else if (drive_is_ready(drive)) {
diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index 376f2dc..f014dd1 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -129,12 +129,12 @@
if ((stat & ATA_BUSY) == 0)
break;
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
*rstat = stat;
return -EBUSY;
}
}
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
/*
* Allow status to settle, then read it again.
diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index 2a744a9..0964500 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -196,10 +196,10 @@
int bswap = 1;
/* local CPU only; some systems need this */
- local_irq_save(flags);
+ local_irq_save_nort(flags);
/* read 512 bytes of id info */
hwif->tp_ops->input_data(drive, NULL, id, SECTOR_SIZE);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
drive->dev_flags |= IDE_DFLAG_ID_READ;
#ifdef DEBUG
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index dabb88b..2cecea7 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -250,7 +250,7 @@
page_is_high = PageHighMem(page);
if (page_is_high)
- local_irq_save(flags);
+ local_irq_save_nort(flags);
buf = kmap_atomic(page) + offset;
@@ -271,7 +271,7 @@
kunmap_atomic(buf);
if (page_is_high)
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
len -= nr_bytes;
}
@@ -414,7 +414,7 @@
}
if ((drive->dev_flags & IDE_DFLAG_UNMASK) == 0)
- local_irq_disable();
+ local_irq_disable_nort();
ide_set_handler(drive, &task_pio_intr, WAIT_WORSTCASE);
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index cecb98a..3800ef5 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -783,7 +783,7 @@
ipoib_mcast_stop_thread(dev, 0);
- local_irq_save(flags);
+ local_irq_save_nort(flags);
netif_addr_lock(dev);
spin_lock(&priv->lock);
@@ -865,7 +865,7 @@
spin_unlock(&priv->lock);
netif_addr_unlock(dev);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
/* We have to cancel outside of the spinlock */
list_for_each_entry_safe(mcast, tmcast, &remove_list, list) {
diff --git a/drivers/input/gameport/gameport.c b/drivers/input/gameport/gameport.c
index 922a7fe..b4fe94b 100644
--- a/drivers/input/gameport/gameport.c
+++ b/drivers/input/gameport/gameport.c
@@ -87,12 +87,12 @@
tx = 1 << 30;
for(i = 0; i < 50; i++) {
- local_irq_save(flags);
+ local_irq_save_nort(flags);
GET_TIME(t1);
for (t = 0; t < 50; t++) gameport_read(gameport);
GET_TIME(t2);
GET_TIME(t3);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
udelay(i * 10);
if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
}
@@ -111,11 +111,11 @@
tx = 1 << 30;
for(i = 0; i < 50; i++) {
- local_irq_save(flags);
+ local_irq_save_nort(flags);
rdtscl(t1);
for (t = 0; t < 50; t++) gameport_read(gameport);
rdtscl(t2);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
udelay(i * 10);
if (t2 - t1 < tx) tx = t2 - t1;
}
diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
index 49794b4..3d7245d 100644
--- a/drivers/leds/trigger/Kconfig
+++ b/drivers/leds/trigger/Kconfig
@@ -61,7 +61,7 @@
config LEDS_TRIGGER_CPU
bool "LED CPU Trigger"
- depends on LEDS_TRIGGERS
+ depends on LEDS_TRIGGERS && !PREEMPT_RT_BASE
help
This allows LEDs to be controlled by active CPUs. This shows
the active CPUs across an array of LEDs so you can see which
diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig
index f950c9d..5eb76dd 100644
--- a/drivers/md/bcache/Kconfig
+++ b/drivers/md/bcache/Kconfig
@@ -1,6 +1,7 @@
config BCACHE
tristate "Block device as cache"
+ depends on !PREEMPT_RT_FULL
---help---
Allows a block device to be used as cache for other devices; uses
a btree for indexing and the layout is optimized for SSDs.
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index fafb82f..525e1a5 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1868,14 +1868,14 @@
if (map_request(ti, clone, md))
goto requeued;
- BUG_ON(!irqs_disabled());
+ BUG_ON_NONRT(!irqs_disabled());
spin_lock(q->queue_lock);
}
goto out;
requeued:
- BUG_ON(!irqs_disabled());
+ BUG_ON_NONRT(!irqs_disabled());
spin_lock(q->queue_lock);
delay_and_out:
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 01757b2..167c4af 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1545,8 +1545,9 @@
struct raid5_percpu *percpu;
unsigned long cpu;
- cpu = get_cpu();
+ cpu = get_cpu_light();
percpu = per_cpu_ptr(conf->percpu, cpu);
+ spin_lock(&percpu->lock);
if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
ops_run_biofill(sh);
overlap_clear++;
@@ -1598,7 +1599,8 @@
if (test_and_clear_bit(R5_Overlap, &dev->flags))
wake_up(&sh->raid_conf->wait_for_overlap);
}
- put_cpu();
+ spin_unlock(&percpu->lock);
+ put_cpu_light();
}
static int grow_one_stripe(struct r5conf *conf)
@@ -5465,6 +5467,7 @@
__func__, cpu);
break;
}
+ spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock);
}
put_online_cpus();
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 2113ffa..0a5e1e1 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -444,6 +444,7 @@
int recovery_disabled;
/* per cpu variables */
struct raid5_percpu {
+ spinlock_t lock; /* Protection for -RT */
struct page *spare_page; /* Used when checking P/Q in raid6 */
void *scribble; /* space for constructing buffer
* lists and performing address
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 3eaafbc..3664c8f 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -63,6 +63,7 @@
config ATMEL_TCLIB
bool "Atmel AT32/AT91 Timer/Counter Library"
depends on (AVR32 || ARCH_AT91)
+ default y if PREEMPT_RT_FULL
help
Select this if you want a library to allocate the Timer/Counter
blocks found on many Atmel processors. This facilitates using
@@ -78,8 +79,7 @@
are combined to make a single 32-bit timer.
When GENERIC_CLOCKEVENTS is defined, the third timer channel
- may be used as a clock event device supporting oneshot mode
- (delays of up to two seconds) based on the 32 KiHz clock.
+ may be used as a clock event device supporting oneshot mode.
config ATMEL_TCB_CLKSRC_BLOCK
int
@@ -93,6 +93,15 @@
TC can be used for other purposes, such as PWM generation and
interval timing.
+config ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
+ bool "TC Block use 32 KiHz clock"
+ depends on ATMEL_TCB_CLKSRC
+ default y if !PREEMPT_RT_FULL
+ help
+ Select this to use 32 KiHz base clock rate as TC block clock
+ source for clock events.
+
+
config DUMMY_IRQ
tristate "Dummy IRQ handler"
default n
@@ -122,6 +131,35 @@
for information on the specific driver level and support statement
for your IBM server.
+config HWLAT_DETECTOR
+ tristate "Testing module to detect hardware-induced latencies"
+ depends on DEBUG_FS
+ depends on RING_BUFFER
+ default m
+ ---help---
+ A simple hardware latency detector. Use this module to detect
+ large latencies introduced by the behavior of the underlying
+ system firmware external to Linux. We do this using periodic
+ use of stop_machine to grab all available CPUs and measure
+ for unexplainable gaps in the CPU timestamp counter(s). By
+ default, the module is not enabled until the "enable" file
+ within the "hwlat_detector" debugfs directory is toggled.
+
+ This module is often used to detect SMI (System Management
+ Interrupts) on x86 systems, though is not x86 specific. To
+ this end, we default to using a sample window of 1 second,
+ during which we will sample for 0.5 seconds. If an SMI or
+ similar event occurs during that time, it is recorded
+ into an 8K samples global ring buffer until retreived.
+
+ WARNING: This software should never be enabled (it can be built
+ but should not be turned on after it is loaded) in a production
+ environment where high latencies are a concern since the
+ sampling mechanism actually introduces latencies for
+ regular tasks while the CPU(s) are being held.
+
+ If unsure, say N
+
config PHANTOM
tristate "Sensable PHANToM (PCI)"
depends on PCI
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index c235d5b..6bb08da40 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -53,3 +53,4 @@
obj-$(CONFIG_VMWARE_VMCI) += vmw_vmci/
obj-$(CONFIG_LATTICE_ECP3_CONFIG) += lattice-ecp3-config.o
obj-$(CONFIG_SRAM) += sram.o
+obj-$(CONFIG_HWLAT_DETECTOR) += hwlat_detector.o
diff --git a/drivers/misc/hwlat_detector.c b/drivers/misc/hwlat_detector.c
new file mode 100644
index 0000000..2429c43
--- /dev/null
+++ b/drivers/misc/hwlat_detector.c
@@ -0,0 +1,1240 @@
+/*
+ * hwlat_detector.c - A simple Hardware Latency detector.
+ *
+ * Use this module to detect large system latencies induced by the behavior of
+ * certain underlying system hardware or firmware, independent of Linux itself.
+ * The code was developed originally to detect the presence of SMIs on Intel
+ * and AMD systems, although there is no dependency upon x86 herein.
+ *
+ * The classical example usage of this module is in detecting the presence of
+ * SMIs or System Management Interrupts on Intel and AMD systems. An SMI is a
+ * somewhat special form of hardware interrupt spawned from earlier CPU debug
+ * modes in which the (BIOS/EFI/etc.) firmware arranges for the South Bridge
+ * LPC (or other device) to generate a special interrupt under certain
+ * circumstances, for example, upon expiration of a special SMI timer device,
+ * due to certain external thermal readings, on certain I/O address accesses,
+ * and other situations. An SMI hits a special CPU pin, triggers a special
+ * SMI mode (complete with special memory map), and the OS is unaware.
+ *
+ * Although certain hardware-inducing latencies are necessary (for example,
+ * a modern system often requires an SMI handler for correct thermal control
+ * and remote management) they can wreak havoc upon any OS-level performance
+ * guarantees toward low-latency, especially when the OS is not even made
+ * aware of the presence of these interrupts. For this reason, we need a
+ * somewhat brute force mechanism to detect these interrupts. In this case,
+ * we do it by hogging all of the CPU(s) for configurable timer intervals,
+ * sampling the built-in CPU timer, looking for discontiguous readings.
+ *
+ * WARNING: This implementation necessarily introduces latencies. Therefore,
+ * you should NEVER use this module in a production environment
+ * requiring any kind of low-latency performance guarantee(s).
+ *
+ * Copyright (C) 2008-2009 Jon Masters, Red Hat, Inc. <jcm@redhat.com>
+ *
+ * Includes useful feedback from Clark Williams <clark@redhat.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/ring_buffer.h>
+#include <linux/time.h>
+#include <linux/hrtimer.h>
+#include <linux/kthread.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include <linux/version.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/trace_clock.h>
+
+#define BUF_SIZE_DEFAULT 262144UL /* 8K*(sizeof(entry)) */
+#define BUF_FLAGS (RB_FL_OVERWRITE) /* no block on full */
+#define U64STR_SIZE 22 /* 20 digits max */
+
+#define VERSION "1.0.0"
+#define BANNER "hwlat_detector: "
+#define DRVNAME "hwlat_detector"
+#define DEFAULT_SAMPLE_WINDOW 1000000 /* 1s */
+#define DEFAULT_SAMPLE_WIDTH 500000 /* 0.5s */
+#define DEFAULT_LAT_THRESHOLD 10 /* 10us */
+
+/* Module metadata */
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jon Masters <jcm@redhat.com>");
+MODULE_DESCRIPTION("A simple hardware latency detector");
+MODULE_VERSION(VERSION);
+
+/* Module parameters */
+
+static int debug;
+static int enabled;
+static int threshold;
+
+module_param(debug, int, 0); /* enable debug */
+module_param(enabled, int, 0); /* enable detector */
+module_param(threshold, int, 0); /* latency threshold */
+
+/* Buffering and sampling */
+
+static struct ring_buffer *ring_buffer; /* sample buffer */
+static DEFINE_MUTEX(ring_buffer_mutex); /* lock changes */
+static unsigned long buf_size = BUF_SIZE_DEFAULT;
+static struct task_struct *kthread; /* sampling thread */
+
+/* DebugFS filesystem entries */
+
+static struct dentry *debug_dir; /* debugfs directory */
+static struct dentry *debug_max; /* maximum TSC delta */
+static struct dentry *debug_count; /* total detect count */
+static struct dentry *debug_sample_width; /* sample width us */
+static struct dentry *debug_sample_window; /* sample window us */
+static struct dentry *debug_sample; /* raw samples us */
+static struct dentry *debug_threshold; /* threshold us */
+static struct dentry *debug_enable; /* enable/disable */
+
+/* Individual samples and global state */
+
+struct sample; /* latency sample */
+struct data; /* Global state */
+
+/* Sampling functions */
+static int __buffer_add_sample(struct sample *sample);
+static struct sample *buffer_get_sample(struct sample *sample);
+
+/* Threading and state */
+static int kthread_fn(void *unused);
+static int start_kthread(void);
+static int stop_kthread(void);
+static void __reset_stats(void);
+static int init_stats(void);
+
+/* Debugfs interface */
+static ssize_t simple_data_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos, const u64 *entry);
+static ssize_t simple_data_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos, u64 *entry);
+static int debug_sample_fopen(struct inode *inode, struct file *filp);
+static ssize_t debug_sample_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos);
+static int debug_sample_release(struct inode *inode, struct file *filp);
+static int debug_enable_fopen(struct inode *inode, struct file *filp);
+static ssize_t debug_enable_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos);
+static ssize_t debug_enable_fwrite(struct file *file,
+ const char __user *user_buffer,
+ size_t user_size, loff_t *offset);
+
+/* Initialization functions */
+static int init_debugfs(void);
+static void free_debugfs(void);
+static int detector_init(void);
+static void detector_exit(void);
+
+/* Individual latency samples are stored here when detected and packed into
+ * the ring_buffer circular buffer, where they are overwritten when
+ * more than buf_size/sizeof(sample) samples are received. */
+struct sample {
+ u64 seqnum; /* unique sequence */
+ u64 duration; /* ktime delta */
+ u64 outer_duration; /* ktime delta (outer loop) */
+ struct timespec timestamp; /* wall time */
+ unsigned long lost;
+};
+
+/* keep the global state somewhere. */
+static struct data {
+
+ struct mutex lock; /* protect changes */
+
+ u64 count; /* total since reset */
+ u64 max_sample; /* max hardware latency */
+ u64 threshold; /* sample threshold level */
+
+ u64 sample_window; /* total sampling window (on+off) */
+ u64 sample_width; /* active sampling portion of window */
+
+ atomic_t sample_open; /* whether the sample file is open */
+
+ wait_queue_head_t wq; /* waitqeue for new sample values */
+
+} data;
+
+/**
+ * __buffer_add_sample - add a new latency sample recording to the ring buffer
+ * @sample: The new latency sample value
+ *
+ * This receives a new latency sample and records it in a global ring buffer.
+ * No additional locking is used in this case.
+ */
+static int __buffer_add_sample(struct sample *sample)
+{
+ return ring_buffer_write(ring_buffer,
+ sizeof(struct sample), sample);
+}
+
+/**
+ * buffer_get_sample - remove a hardware latency sample from the ring buffer
+ * @sample: Pre-allocated storage for the sample
+ *
+ * This retrieves a hardware latency sample from the global circular buffer
+ */
+static struct sample *buffer_get_sample(struct sample *sample)
+{
+ struct ring_buffer_event *e = NULL;
+ struct sample *s = NULL;
+ unsigned int cpu = 0;
+
+ if (!sample)
+ return NULL;
+
+ mutex_lock(&ring_buffer_mutex);
+ for_each_online_cpu(cpu) {
+ e = ring_buffer_consume(ring_buffer, cpu, NULL, &sample->lost);
+ if (e)
+ break;
+ }
+
+ if (e) {
+ s = ring_buffer_event_data(e);
+ memcpy(sample, s, sizeof(struct sample));
+ } else
+ sample = NULL;
+ mutex_unlock(&ring_buffer_mutex);
+
+ return sample;
+}
+
+#ifndef CONFIG_TRACING
+#define time_type ktime_t
+#define time_get() ktime_get()
+#define time_to_us(x) ktime_to_us(x)
+#define time_sub(a, b) ktime_sub(a, b)
+#define init_time(a, b) (a).tv64 = b
+#define time_u64(a) ((a).tv64)
+#else
+#define time_type u64
+#define time_get() trace_clock_local()
+#define time_to_us(x) div_u64(x, 1000)
+#define time_sub(a, b) ((a) - (b))
+#define init_time(a, b) (a = b)
+#define time_u64(a) a
+#endif
+/**
+ * get_sample - sample the CPU TSC and look for likely hardware latencies
+ *
+ * Used to repeatedly capture the CPU TSC (or similar), looking for potential
+ * hardware-induced latency. Called with interrupts disabled and with
+ * data.lock held.
+ */
+static int get_sample(void)
+{
+ time_type start, t1, t2, last_t2;
+ s64 diff, total = 0;
+ u64 sample = 0;
+ u64 outer_sample = 0;
+ int ret = -1;
+
+ init_time(last_t2, 0);
+ start = time_get(); /* start timestamp */
+
+ do {
+
+ t1 = time_get(); /* we'll look for a discontinuity */
+ t2 = time_get();
+
+ if (time_u64(last_t2)) {
+ /* Check the delta from outer loop (t2 to next t1) */
+ diff = time_to_us(time_sub(t1, last_t2));
+ /* This shouldn't happen */
+ if (diff < 0) {
+ pr_err(BANNER "time running backwards\n");
+ goto out;
+ }
+ if (diff > outer_sample)
+ outer_sample = diff;
+ }
+ last_t2 = t2;
+
+ total = time_to_us(time_sub(t2, start)); /* sample width */
+
+ /* This checks the inner loop (t1 to t2) */
+ diff = time_to_us(time_sub(t2, t1)); /* current diff */
+
+ /* This shouldn't happen */
+ if (diff < 0) {
+ pr_err(BANNER "time running backwards\n");
+ goto out;
+ }
+
+ if (diff > sample)
+ sample = diff; /* only want highest value */
+
+ } while (total <= data.sample_width);
+
+ ret = 0;
+
+ /* If we exceed the threshold value, we have found a hardware latency */
+ if (sample > data.threshold || outer_sample > data.threshold) {
+ struct sample s;
+
+ ret = 1;
+
+ data.count++;
+ s.seqnum = data.count;
+ s.duration = sample;
+ s.outer_duration = outer_sample;
+ s.timestamp = CURRENT_TIME;
+ __buffer_add_sample(&s);
+
+ /* Keep a running maximum ever recorded hardware latency */
+ if (sample > data.max_sample)
+ data.max_sample = sample;
+ }
+
+out:
+ return ret;
+}
+
+/*
+ * kthread_fn - The CPU time sampling/hardware latency detection kernel thread
+ * @unused: A required part of the kthread API.
+ *
+ * Used to periodically sample the CPU TSC via a call to get_sample. We
+ * disable interrupts, which does (intentionally) introduce latency since we
+ * need to ensure nothing else might be running (and thus pre-empting).
+ * Obviously this should never be used in production environments.
+ *
+ * Currently this runs on which ever CPU it was scheduled on, but most
+ * real-worald hardware latency situations occur across several CPUs,
+ * but we might later generalize this if we find there are any actualy
+ * systems with alternate SMI delivery or other hardware latencies.
+ */
+static int kthread_fn(void *unused)
+{
+ int ret;
+ u64 interval;
+
+ while (!kthread_should_stop()) {
+
+ mutex_lock(&data.lock);
+
+ local_irq_disable();
+ ret = get_sample();
+ local_irq_enable();
+
+ if (ret > 0)
+ wake_up(&data.wq); /* wake up reader(s) */
+
+ interval = data.sample_window - data.sample_width;
+ do_div(interval, USEC_PER_MSEC); /* modifies interval value */
+
+ mutex_unlock(&data.lock);
+
+ if (msleep_interruptible(interval))
+ break;
+ }
+
+ return 0;
+}
+
+/**
+ * start_kthread - Kick off the hardware latency sampling/detector kthread
+ *
+ * This starts a kernel thread that will sit and sample the CPU timestamp
+ * counter (TSC or similar) and look for potential hardware latencies.
+ */
+static int start_kthread(void)
+{
+ kthread = kthread_run(kthread_fn, NULL,
+ DRVNAME);
+ if (IS_ERR(kthread)) {
+ pr_err(BANNER "could not start sampling thread\n");
+ enabled = 0;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+/**
+ * stop_kthread - Inform the hardware latency samping/detector kthread to stop
+ *
+ * This kicks the running hardware latency sampling/detector kernel thread and
+ * tells it to stop sampling now. Use this on unload and at system shutdown.
+ */
+static int stop_kthread(void)
+{
+ int ret;
+
+ ret = kthread_stop(kthread);
+
+ return ret;
+}
+
+/**
+ * __reset_stats - Reset statistics for the hardware latency detector
+ *
+ * We use data to store various statistics and global state. We call this
+ * function in order to reset those when "enable" is toggled on or off, and
+ * also at initialization. Should be called with data.lock held.
+ */
+static void __reset_stats(void)
+{
+ data.count = 0;
+ data.max_sample = 0;
+ ring_buffer_reset(ring_buffer); /* flush out old sample entries */
+}
+
+/**
+ * init_stats - Setup global state statistics for the hardware latency detector
+ *
+ * We use data to store various statistics and global state. We also use
+ * a global ring buffer (ring_buffer) to keep raw samples of detected hardware
+ * induced system latencies. This function initializes these structures and
+ * allocates the global ring buffer also.
+ */
+static int init_stats(void)
+{
+ int ret = -ENOMEM;
+
+ mutex_init(&data.lock);
+ init_waitqueue_head(&data.wq);
+ atomic_set(&data.sample_open, 0);
+
+ ring_buffer = ring_buffer_alloc(buf_size, BUF_FLAGS);
+
+ if (WARN(!ring_buffer, KERN_ERR BANNER
+ "failed to allocate ring buffer!\n"))
+ goto out;
+
+ __reset_stats();
+ data.threshold = threshold ?: DEFAULT_LAT_THRESHOLD; /* threshold us */
+ data.sample_window = DEFAULT_SAMPLE_WINDOW; /* window us */
+ data.sample_width = DEFAULT_SAMPLE_WIDTH; /* width us */
+
+ ret = 0;
+
+out:
+ return ret;
+
+}
+
+/*
+ * simple_data_read - Wrapper read function for global state debugfs entries
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ * @entry: The entry to read from
+ *
+ * This function provides a generic read implementation for the global state
+ * "data" structure debugfs filesystem entries. It would be nice to use
+ * simple_attr_read directly, but we need to make sure that the data.lock
+ * is held during the actual read.
+ */
+static ssize_t simple_data_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos, const u64 *entry)
+{
+ char buf[U64STR_SIZE];
+ u64 val = 0;
+ int len = 0;
+
+ memset(buf, 0, sizeof(buf));
+
+ if (!entry)
+ return -EFAULT;
+
+ mutex_lock(&data.lock);
+ val = *entry;
+ mutex_unlock(&data.lock);
+
+ len = snprintf(buf, sizeof(buf), "%llu\n", (unsigned long long)val);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
+
+}
+
+/*
+ * simple_data_write - Wrapper write function for global state debugfs entries
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to write value from
+ * @cnt: The maximum number of bytes to write
+ * @ppos: The current "file" position
+ * @entry: The entry to write to
+ *
+ * This function provides a generic write implementation for the global state
+ * "data" structure debugfs filesystem entries. It would be nice to use
+ * simple_attr_write directly, but we need to make sure that the data.lock
+ * is held during the actual write.
+ */
+static ssize_t simple_data_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos, u64 *entry)
+{
+ char buf[U64STR_SIZE];
+ int csize = min(cnt, sizeof(buf));
+ u64 val = 0;
+ int err = 0;
+
+ memset(buf, '\0', sizeof(buf));
+ if (copy_from_user(buf, ubuf, csize))
+ return -EFAULT;
+
+ buf[U64STR_SIZE-1] = '\0'; /* just in case */
+ err = kstrtoull(buf, 10, &val);
+ if (err)
+ return -EINVAL;
+
+ mutex_lock(&data.lock);
+ *entry = val;
+ mutex_unlock(&data.lock);
+
+ return csize;
+}
+
+/**
+ * debug_count_fopen - Open function for "count" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "count" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_count_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_count_fread - Read function for "count" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "count" debugfs
+ * interface to the hardware latency detector. Can be used to read the
+ * number of latency readings exceeding the configured threshold since
+ * the detector was last reset (e.g. by writing a zero into "count").
+ */
+static ssize_t debug_count_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_data_read(filp, ubuf, cnt, ppos, &data.count);
+}
+
+/**
+ * debug_count_fwrite - Write function for "count" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "count" debugfs
+ * interface to the hardware latency detector. Can be used to write a
+ * desired value, especially to zero the total count.
+ */
+static ssize_t debug_count_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ return simple_data_write(filp, ubuf, cnt, ppos, &data.count);
+}
+
+/**
+ * debug_enable_fopen - Dummy open function for "enable" debugfs interface
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "enable" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_enable_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_enable_fread - Read function for "enable" debugfs interface
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "enable" debugfs
+ * interface to the hardware latency detector. Can be used to determine
+ * whether the detector is currently enabled ("0\n" or "1\n" returned).
+ */
+static ssize_t debug_enable_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[4];
+
+ if ((cnt < sizeof(buf)) || (*ppos))
+ return 0;
+
+ buf[0] = enabled ? '1' : '0';
+ buf[1] = '\n';
+ buf[2] = '\0';
+ if (copy_to_user(ubuf, buf, strlen(buf)))
+ return -EFAULT;
+ return *ppos = strlen(buf);
+}
+
+/**
+ * debug_enable_fwrite - Write function for "enable" debugfs interface
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "enable" debugfs
+ * interface to the hardware latency detector. Can be used to enable or
+ * disable the detector, which will have the side-effect of possibly
+ * also resetting the global stats and kicking off the measuring
+ * kthread (on an enable) or the converse (upon a disable).
+ */
+static ssize_t debug_enable_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ char buf[4];
+ int csize = min(cnt, sizeof(buf));
+ long val = 0;
+ int err = 0;
+
+ memset(buf, '\0', sizeof(buf));
+ if (copy_from_user(buf, ubuf, csize))
+ return -EFAULT;
+
+ buf[sizeof(buf)-1] = '\0'; /* just in case */
+ err = kstrtoul(buf, 10, &val);
+ if (0 != err)
+ return -EINVAL;
+
+ if (val) {
+ if (enabled)
+ goto unlock;
+ enabled = 1;
+ __reset_stats();
+ if (start_kthread())
+ return -EFAULT;
+ } else {
+ if (!enabled)
+ goto unlock;
+ enabled = 0;
+ err = stop_kthread();
+ if (err) {
+ pr_err(BANNER "cannot stop kthread\n");
+ return -EFAULT;
+ }
+ wake_up(&data.wq); /* reader(s) should return */
+ }
+unlock:
+ return csize;
+}
+
+/**
+ * debug_max_fopen - Open function for "max" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "max" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_max_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_max_fread - Read function for "max" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "max" debugfs
+ * interface to the hardware latency detector. Can be used to determine
+ * the maximum latency value observed since it was last reset.
+ */
+static ssize_t debug_max_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_data_read(filp, ubuf, cnt, ppos, &data.max_sample);
+}
+
+/**
+ * debug_max_fwrite - Write function for "max" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "max" debugfs
+ * interface to the hardware latency detector. Can be used to reset the
+ * maximum or set it to some other desired value - if, then, subsequent
+ * measurements exceed this value, the maximum will be updated.
+ */
+static ssize_t debug_max_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ return simple_data_write(filp, ubuf, cnt, ppos, &data.max_sample);
+}
+
+
+/**
+ * debug_sample_fopen - An open function for "sample" debugfs interface
+ * @inode: The in-kernel inode representation of this debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function handles opening the "sample" file within the hardware
+ * latency detector debugfs directory interface. This file is used to read
+ * raw samples from the global ring_buffer and allows the user to see a
+ * running latency history. Can be opened blocking or non-blocking,
+ * affecting whether it behaves as a buffer read pipe, or does not.
+ * Implements simple locking to prevent multiple simultaneous use.
+ */
+static int debug_sample_fopen(struct inode *inode, struct file *filp)
+{
+ if (!atomic_add_unless(&data.sample_open, 1, 1))
+ return -EBUSY;
+ else
+ return 0;
+}
+
+/**
+ * debug_sample_fread - A read function for "sample" debugfs interface
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that will contain the samples read
+ * @cnt: The maximum bytes to read from the debugfs "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function handles reading from the "sample" file within the hardware
+ * latency detector debugfs directory interface. This file is used to read
+ * raw samples from the global ring_buffer and allows the user to see a
+ * running latency history. By default this will block pending a new
+ * value written into the sample buffer, unless there are already a
+ * number of value(s) waiting in the buffer, or the sample file was
+ * previously opened in a non-blocking mode of operation.
+ */
+static ssize_t debug_sample_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ int len = 0;
+ char buf[64];
+ struct sample *sample = NULL;
+
+ if (!enabled)
+ return 0;
+
+ sample = kzalloc(sizeof(struct sample), GFP_KERNEL);
+ if (!sample)
+ return -ENOMEM;
+
+ while (!buffer_get_sample(sample)) {
+
+ DEFINE_WAIT(wait);
+
+ if (filp->f_flags & O_NONBLOCK) {
+ len = -EAGAIN;
+ goto out;
+ }
+
+ prepare_to_wait(&data.wq, &wait, TASK_INTERRUPTIBLE);
+ schedule();
+ finish_wait(&data.wq, &wait);
+
+ if (signal_pending(current)) {
+ len = -EINTR;
+ goto out;
+ }
+
+ if (!enabled) { /* enable was toggled */
+ len = 0;
+ goto out;
+ }
+ }
+
+ len = snprintf(buf, sizeof(buf), "%010lu.%010lu\t%llu\t%llu\n",
+ sample->timestamp.tv_sec,
+ sample->timestamp.tv_nsec,
+ sample->duration,
+ sample->outer_duration);
+
+
+ /* handling partial reads is more trouble than it's worth */
+ if (len > cnt)
+ goto out;
+
+ if (copy_to_user(ubuf, buf, len))
+ len = -EFAULT;
+
+out:
+ kfree(sample);
+ return len;
+}
+
+/**
+ * debug_sample_release - Release function for "sample" debugfs interface
+ * @inode: The in-kernel inode represenation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function completes the close of the debugfs interface "sample" file.
+ * Frees the sample_open "lock" so that other users may open the interface.
+ */
+static int debug_sample_release(struct inode *inode, struct file *filp)
+{
+ atomic_dec(&data.sample_open);
+
+ return 0;
+}
+
+/**
+ * debug_threshold_fopen - Open function for "threshold" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "threshold" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_threshold_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_threshold_fread - Read function for "threshold" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "threshold" debugfs
+ * interface to the hardware latency detector. It can be used to determine
+ * the current threshold level at which a latency will be recorded in the
+ * global ring buffer, typically on the order of 10us.
+ */
+static ssize_t debug_threshold_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_data_read(filp, ubuf, cnt, ppos, &data.threshold);
+}
+
+/**
+ * debug_threshold_fwrite - Write function for "threshold" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "threshold" debugfs
+ * interface to the hardware latency detector. It can be used to configure
+ * the threshold level at which any subsequently detected latencies will
+ * be recorded into the global ring buffer.
+ */
+static ssize_t debug_threshold_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ int ret;
+
+ ret = simple_data_write(filp, ubuf, cnt, ppos, &data.threshold);
+
+ if (enabled)
+ wake_up_process(kthread);
+
+ return ret;
+}
+
+/**
+ * debug_width_fopen - Open function for "width" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "width" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_width_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_width_fread - Read function for "width" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "width" debugfs
+ * interface to the hardware latency detector. It can be used to determine
+ * for how many us of the total window us we will actively sample for any
+ * hardware-induced latecy periods. Obviously, it is not possible to
+ * sample constantly and have the system respond to a sample reader, or,
+ * worse, without having the system appear to have gone out to lunch.
+ */
+static ssize_t debug_width_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_data_read(filp, ubuf, cnt, ppos, &data.sample_width);
+}
+
+/**
+ * debug_width_fwrite - Write function for "width" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "width" debugfs
+ * interface to the hardware latency detector. It can be used to configure
+ * for how many us of the total window us we will actively sample for any
+ * hardware-induced latency periods. Obviously, it is not possible to
+ * sample constantly and have the system respond to a sample reader, or,
+ * worse, without having the system appear to have gone out to lunch. It
+ * is enforced that width is less that the total window size.
+ */
+static ssize_t debug_width_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ char buf[U64STR_SIZE];
+ int csize = min(cnt, sizeof(buf));
+ u64 val = 0;
+ int err = 0;
+
+ memset(buf, '\0', sizeof(buf));
+ if (copy_from_user(buf, ubuf, csize))
+ return -EFAULT;
+
+ buf[U64STR_SIZE-1] = '\0'; /* just in case */
+ err = kstrtoull(buf, 10, &val);
+ if (0 != err)
+ return -EINVAL;
+
+ mutex_lock(&data.lock);
+ if (val < data.sample_window)
+ data.sample_width = val;
+ else {
+ mutex_unlock(&data.lock);
+ return -EINVAL;
+ }
+ mutex_unlock(&data.lock);
+
+ if (enabled)
+ wake_up_process(kthread);
+
+ return csize;
+}
+
+/**
+ * debug_window_fopen - Open function for "window" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "window" debugfs
+ * interface to the hardware latency detector. The window is the total time
+ * in us that will be considered one sample period. Conceptually, windows
+ * occur back-to-back and contain a sample width period during which
+ * actual sampling occurs.
+ */
+static int debug_window_fopen(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+/**
+ * debug_window_fread - Read function for "window" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "window" debugfs
+ * interface to the hardware latency detector. The window is the total time
+ * in us that will be considered one sample period. Conceptually, windows
+ * occur back-to-back and contain a sample width period during which
+ * actual sampling occurs. Can be used to read the total window size.
+ */
+static ssize_t debug_window_fread(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_data_read(filp, ubuf, cnt, ppos, &data.sample_window);
+}
+
+/**
+ * debug_window_fwrite - Write function for "window" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "window" debufds
+ * interface to the hardware latency detetector. The window is the total time
+ * in us that will be considered one sample period. Conceptually, windows
+ * occur back-to-back and contain a sample width period during which
+ * actual sampling occurs. Can be used to write a new total window size. It
+ * is enfoced that any value written must be greater than the sample width
+ * size, or an error results.
+ */
+static ssize_t debug_window_fwrite(struct file *filp,
+ const char __user *ubuf,
+ size_t cnt,
+ loff_t *ppos)
+{
+ char buf[U64STR_SIZE];
+ int csize = min(cnt, sizeof(buf));
+ u64 val = 0;
+ int err = 0;
+
+ memset(buf, '\0', sizeof(buf));
+ if (copy_from_user(buf, ubuf, csize))
+ return -EFAULT;
+
+ buf[U64STR_SIZE-1] = '\0'; /* just in case */
+ err = kstrtoull(buf, 10, &val);
+ if (0 != err)
+ return -EINVAL;
+
+ mutex_lock(&data.lock);
+ if (data.sample_width < val)
+ data.sample_window = val;
+ else {
+ mutex_unlock(&data.lock);
+ return -EINVAL;
+ }
+ mutex_unlock(&data.lock);
+
+ return csize;
+}
+
+/*
+ * Function pointers for the "count" debugfs file operations
+ */
+static const struct file_operations count_fops = {
+ .open = debug_count_fopen,
+ .read = debug_count_fread,
+ .write = debug_count_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "enable" debugfs file operations
+ */
+static const struct file_operations enable_fops = {
+ .open = debug_enable_fopen,
+ .read = debug_enable_fread,
+ .write = debug_enable_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "max" debugfs file operations
+ */
+static const struct file_operations max_fops = {
+ .open = debug_max_fopen,
+ .read = debug_max_fread,
+ .write = debug_max_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "sample" debugfs file operations
+ */
+static const struct file_operations sample_fops = {
+ .open = debug_sample_fopen,
+ .read = debug_sample_fread,
+ .release = debug_sample_release,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "threshold" debugfs file operations
+ */
+static const struct file_operations threshold_fops = {
+ .open = debug_threshold_fopen,
+ .read = debug_threshold_fread,
+ .write = debug_threshold_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "width" debugfs file operations
+ */
+static const struct file_operations width_fops = {
+ .open = debug_width_fopen,
+ .read = debug_width_fread,
+ .write = debug_width_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "window" debugfs file operations
+ */
+static const struct file_operations window_fops = {
+ .open = debug_window_fopen,
+ .read = debug_window_fread,
+ .write = debug_window_fwrite,
+ .owner = THIS_MODULE,
+};
+
+/**
+ * init_debugfs - A function to initialize the debugfs interface files
+ *
+ * This function creates entries in debugfs for "hwlat_detector", including
+ * files to read values from the detector, current samples, and the
+ * maximum sample that has been captured since the hardware latency
+ * dectector was started.
+ */
+static int init_debugfs(void)
+{
+ int ret = -ENOMEM;
+
+ debug_dir = debugfs_create_dir(DRVNAME, NULL);
+ if (!debug_dir)
+ goto err_debug_dir;
+
+ debug_sample = debugfs_create_file("sample", 0444,
+ debug_dir, NULL,
+ &sample_fops);
+ if (!debug_sample)
+ goto err_sample;
+
+ debug_count = debugfs_create_file("count", 0444,
+ debug_dir, NULL,
+ &count_fops);
+ if (!debug_count)
+ goto err_count;
+
+ debug_max = debugfs_create_file("max", 0444,
+ debug_dir, NULL,
+ &max_fops);
+ if (!debug_max)
+ goto err_max;
+
+ debug_sample_window = debugfs_create_file("window", 0644,
+ debug_dir, NULL,
+ &window_fops);
+ if (!debug_sample_window)
+ goto err_window;
+
+ debug_sample_width = debugfs_create_file("width", 0644,
+ debug_dir, NULL,
+ &width_fops);
+ if (!debug_sample_width)
+ goto err_width;
+
+ debug_threshold = debugfs_create_file("threshold", 0644,
+ debug_dir, NULL,
+ &threshold_fops);
+ if (!debug_threshold)
+ goto err_threshold;
+
+ debug_enable = debugfs_create_file("enable", 0644,
+ debug_dir, &enabled,
+ &enable_fops);
+ if (!debug_enable)
+ goto err_enable;
+
+ else {
+ ret = 0;
+ goto out;
+ }
+
+err_enable:
+ debugfs_remove(debug_threshold);
+err_threshold:
+ debugfs_remove(debug_sample_width);
+err_width:
+ debugfs_remove(debug_sample_window);
+err_window:
+ debugfs_remove(debug_max);
+err_max:
+ debugfs_remove(debug_count);
+err_count:
+ debugfs_remove(debug_sample);
+err_sample:
+ debugfs_remove(debug_dir);
+err_debug_dir:
+out:
+ return ret;
+}
+
+/**
+ * free_debugfs - A function to cleanup the debugfs file interface
+ */
+static void free_debugfs(void)
+{
+ /* could also use a debugfs_remove_recursive */
+ debugfs_remove(debug_enable);
+ debugfs_remove(debug_threshold);
+ debugfs_remove(debug_sample_width);
+ debugfs_remove(debug_sample_window);
+ debugfs_remove(debug_max);
+ debugfs_remove(debug_count);
+ debugfs_remove(debug_sample);
+ debugfs_remove(debug_dir);
+}
+
+/**
+ * detector_init - Standard module initialization code
+ */
+static int detector_init(void)
+{
+ int ret = -ENOMEM;
+
+ pr_info(BANNER "version %s\n", VERSION);
+
+ ret = init_stats();
+ if (0 != ret)
+ goto out;
+
+ ret = init_debugfs();
+ if (0 != ret)
+ goto err_stats;
+
+ if (enabled)
+ ret = start_kthread();
+
+ goto out;
+
+err_stats:
+ ring_buffer_free(ring_buffer);
+out:
+ return ret;
+
+}
+
+/**
+ * detector_exit - Standard module cleanup code
+ */
+static void detector_exit(void)
+{
+ int err;
+
+ if (enabled) {
+ enabled = 0;
+ err = stop_kthread();
+ if (err)
+ pr_err(BANNER "cannot stop kthread\n");
+ }
+
+ free_debugfs();
+ ring_buffer_free(ring_buffer); /* free up the ring buffer */
+
+}
+
+module_init(detector_init);
+module_exit(detector_exit);
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 3755f4a..383b559 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1023,15 +1023,12 @@
struct sg_mapping_iter *sg_miter = &host->sg_miter;
struct variant_data *variant = host->variant;
void __iomem *base = host->base;
- unsigned long flags;
u32 status;
status = readl(base + MMCISTATUS);
dev_dbg(mmc_dev(host->mmc), "irq1 (pio) %08x\n", status);
- local_irq_save(flags);
-
do {
unsigned int remain, len;
char *buffer;
@@ -1071,8 +1068,6 @@
sg_miter_stop(sg_miter);
- local_irq_restore(flags);
-
/*
* If we have less than the fifo 'half-full' threshold to transfer,
* trigger a PIO interrupt as soon as any data is available.
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 367aabc..0d6e036 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -161,6 +161,7 @@
config NETCONSOLE
tristate "Network console logging support"
+ depends on !PREEMPT_RT_FULL
---help---
If you want to log kernel messages over the network, enable this.
See <file:Documentation/networking/netconsole.txt> for details.
diff --git a/drivers/net/ethernet/3com/3c59x.c b/drivers/net/ethernet/3com/3c59x.c
index ad5272b..55dd320 100644
--- a/drivers/net/ethernet/3com/3c59x.c
+++ b/drivers/net/ethernet/3com/3c59x.c
@@ -842,9 +842,9 @@
{
struct vortex_private *vp = netdev_priv(dev);
unsigned long flags;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
(vp->full_bus_master_rx ? boomerang_interrupt:vortex_interrupt)(dev->irq,dev);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
#endif
@@ -1917,12 +1917,12 @@
* Block interrupts because vortex_interrupt does a bare spin_lock()
*/
unsigned long flags;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
if (vp->full_bus_master_tx)
boomerang_interrupt(dev->irq, dev);
else
vortex_interrupt(dev->irq, dev);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
}
diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
index fd1b001..ddae8c8 100644
--- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
+++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
@@ -2205,11 +2205,7 @@
}
tpd_req = atl1c_cal_tpd_req(skb);
- if (!spin_trylock_irqsave(&adapter->tx_lock, flags)) {
- if (netif_msg_pktdata(adapter))
- dev_info(&adapter->pdev->dev, "tx locked\n");
- return NETDEV_TX_LOCKED;
- }
+ spin_lock_irqsave(&adapter->tx_lock, flags);
if (atl1c_tpd_avail(adapter, type) < tpd_req) {
/* no enough descriptor, just stop queue */
diff --git a/drivers/net/ethernet/atheros/atl1e/atl1e_main.c b/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
index 1966444..d398960 100644
--- a/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
+++ b/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
@@ -1838,8 +1838,7 @@
return NETDEV_TX_OK;
}
tpd_req = atl1e_cal_tdp_req(skb);
- if (!spin_trylock_irqsave(&adapter->tx_lock, flags))
- return NETDEV_TX_LOCKED;
+ spin_lock_irqsave(&adapter->tx_lock, flags);
if (atl1e_tpd_avail(adapter) < tpd_req) {
/* no enough descriptor, just stop queue */
diff --git a/drivers/net/ethernet/chelsio/cxgb/sge.c b/drivers/net/ethernet/chelsio/cxgb/sge.c
index 8061fb0..bfe5c72 100644
--- a/drivers/net/ethernet/chelsio/cxgb/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb/sge.c
@@ -1665,8 +1665,7 @@
struct cmdQ *q = &sge->cmdQ[qid];
unsigned int credits, pidx, genbit, count, use_sched_skb = 0;
- if (!spin_trylock(&q->lock))
- return NETDEV_TX_LOCKED;
+ spin_lock(&q->lock);
reclaim_completed_tx(sge, q);
diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 9fbe4dd..df27493 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -134,7 +134,6 @@
static void gfar_netpoll(struct net_device *dev);
#endif
int gfar_clean_rx_ring(struct gfar_priv_rx_q *rx_queue, int rx_work_limit);
-static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue);
static void gfar_process_frame(struct net_device *dev, struct sk_buff *skb,
int amount_pull, struct napi_struct *napi);
void gfar_halt(struct net_device *dev);
@@ -1301,7 +1300,7 @@
if (netif_running(ndev)) {
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
lock_rx_qs(priv);
@@ -1319,7 +1318,7 @@
unlock_rx_qs(priv);
unlock_tx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
disable_napi(priv);
@@ -1361,7 +1360,7 @@
/* Disable Magic Packet mode, in case something
* else woke us up.
*/
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
lock_rx_qs(priv);
@@ -1373,7 +1372,7 @@
unlock_rx_qs(priv);
unlock_tx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
netif_device_attach(ndev);
@@ -1701,7 +1700,7 @@
/* Lock it down */
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
lock_rx_qs(priv);
@@ -1709,7 +1708,7 @@
unlock_rx_qs(priv);
unlock_tx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
/* Free the IRQs */
if (priv->device_flags & FSL_GIANFAR_DEV_HAS_MULTI_INTR) {
@@ -2387,7 +2386,7 @@
u32 tempval;
regs = priv->gfargrp[0].regs;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_rx_qs(priv);
if (features & NETIF_F_HW_VLAN_CTAG_TX) {
@@ -2420,7 +2419,7 @@
gfar_change_mtu(dev, dev->mtu);
unlock_rx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
static int gfar_change_mtu(struct net_device *dev, int new_mtu)
@@ -2516,7 +2515,7 @@
}
/* Interrupt Handler for Transmit complete */
-static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue)
+static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue)
{
struct net_device *dev = tx_queue->dev;
struct netdev_queue *txq;
@@ -2616,6 +2615,7 @@
tx_queue->dirty_tx = bdp;
netdev_tx_completed_queue(txq, howmany, bytes_sent);
+ return howmany;
}
static void gfar_schedule_cleanup(struct gfar_priv_grp *gfargrp)
@@ -2939,10 +2939,14 @@
tx_queue = priv->tx_queue[i];
/* run Tx cleanup to completion */
if (tx_queue->tx_skbuff[tx_queue->skb_dirtytx]) {
- gfar_clean_tx_ring(tx_queue);
- has_tx_work = 1;
+ int ret;
+
+ ret = gfar_clean_tx_ring(tx_queue);
+ if (ret)
+ has_tx_work++;
}
}
+ work_done += has_tx_work;
for_each_set_bit(i, &gfargrp->rx_bit_map, priv->num_rx_queues) {
/* skip queue if not active */
@@ -3101,7 +3105,7 @@
struct phy_device *phydev = priv->phydev;
int new_state = 0;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
if (phydev->link) {
@@ -3175,7 +3179,7 @@
if (new_state && netif_msg_link(priv))
phy_print_status(phydev);
unlock_tx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
/* Update the hash table based on the current list of multicast
@@ -3381,14 +3385,14 @@
dev->stats.tx_dropped++;
atomic64_inc(&priv->extra_stats.tx_underrun);
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
/* Reactivate the Tx Queues */
gfar_write(®s->tstat, gfargrp->tstat);
unlock_tx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
netif_dbg(priv, tx_err, dev, "Transmit Error\n");
}
diff --git a/drivers/net/ethernet/freescale/gianfar_ethtool.c b/drivers/net/ethernet/freescale/gianfar_ethtool.c
index c0f7328..7f953ea 100644
--- a/drivers/net/ethernet/freescale/gianfar_ethtool.c
+++ b/drivers/net/ethernet/freescale/gianfar_ethtool.c
@@ -501,7 +501,7 @@
/* Halt TX and RX, and process the frames which
* have already been received
*/
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
lock_rx_qs(priv);
@@ -509,7 +509,7 @@
unlock_rx_qs(priv);
unlock_tx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
for (i = 0; i < priv->num_rx_queues; i++)
gfar_clean_rx_ring(priv->rx_queue[i],
@@ -627,7 +627,7 @@
/* Halt TX and RX, and process the frames which
* have already been received
*/
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
lock_rx_qs(priv);
@@ -635,7 +635,7 @@
unlock_tx_qs(priv);
unlock_rx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
for (i = 0; i < priv->num_rx_queues; i++)
gfar_clean_rx_ring(priv->rx_queue[i],
diff --git a/drivers/net/ethernet/freescale/gianfar_sysfs.c b/drivers/net/ethernet/freescale/gianfar_sysfs.c
index acb55af..f0160e67 100644
--- a/drivers/net/ethernet/freescale/gianfar_sysfs.c
+++ b/drivers/net/ethernet/freescale/gianfar_sysfs.c
@@ -68,7 +68,7 @@
return count;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_rx_qs(priv);
/* Set the new stashing value */
@@ -84,7 +84,7 @@
gfar_write(®s->attr, temp);
unlock_rx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return count;
}
@@ -112,7 +112,7 @@
if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_BUF_STASHING))
return count;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_rx_qs(priv);
if (length > priv->rx_buffer_size)
@@ -140,7 +140,7 @@
out:
unlock_rx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return count;
}
@@ -171,7 +171,7 @@
if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_BUF_STASHING))
return count;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_rx_qs(priv);
if (index > priv->rx_stash_size)
@@ -189,7 +189,7 @@
out:
unlock_rx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return count;
}
@@ -219,7 +219,7 @@
if (length > GFAR_MAX_FIFO_THRESHOLD)
return count;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
priv->fifo_threshold = length;
@@ -230,7 +230,7 @@
gfar_write(®s->fifo_tx_thr, temp);
unlock_tx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return count;
}
@@ -259,7 +259,7 @@
if (num > GFAR_MAX_FIFO_STARVE)
return count;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
priv->fifo_starve = num;
@@ -270,7 +270,7 @@
gfar_write(®s->fifo_tx_starve, temp);
unlock_tx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return count;
}
@@ -300,7 +300,7 @@
if (num > GFAR_MAX_FIFO_STARVE_OFF)
return count;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
lock_tx_qs(priv);
priv->fifo_starve_off = num;
@@ -311,7 +311,7 @@
gfar_write(®s->fifo_tx_starve_shutoff, temp);
unlock_tx_qs(priv);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return count;
}
diff --git a/drivers/net/ethernet/neterion/s2io.c b/drivers/net/ethernet/neterion/s2io.c
index 51b0094..809d92c 100644
--- a/drivers/net/ethernet/neterion/s2io.c
+++ b/drivers/net/ethernet/neterion/s2io.c
@@ -4089,12 +4089,7 @@
[skb->priority & (MAX_TX_FIFOS - 1)];
fifo = &mac_control->fifos[queue];
- if (do_spin_lock)
- spin_lock_irqsave(&fifo->tx_lock, flags);
- else {
- if (unlikely(!spin_trylock_irqsave(&fifo->tx_lock, flags)))
- return NETDEV_TX_LOCKED;
- }
+ spin_lock_irqsave(&fifo->tx_lock, flags);
if (sp->config.multiq) {
if (__netif_subqueue_stopped(dev, fifo->fifo_no)) {
diff --git a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
index 5a0f04c..e732812 100644
--- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
+++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
@@ -2148,10 +2148,8 @@
struct pch_gbe_tx_ring *tx_ring = adapter->tx_ring;
unsigned long flags;
- if (!spin_trylock_irqsave(&tx_ring->tx_lock, flags)) {
- /* Collision - tell upper layer to requeue */
- return NETDEV_TX_LOCKED;
- }
+ spin_lock_irqsave(&tx_ring->tx_lock, flags);
+
if (unlikely(!PCH_GBE_DESC_UNUSED(tx_ring))) {
netif_stop_queue(netdev);
spin_unlock_irqrestore(&tx_ring->tx_lock, flags);
diff --git a/drivers/net/ethernet/realtek/8139too.c b/drivers/net/ethernet/realtek/8139too.c
index 942673f..916049e 100644
--- a/drivers/net/ethernet/realtek/8139too.c
+++ b/drivers/net/ethernet/realtek/8139too.c
@@ -2213,7 +2213,7 @@
struct rtl8139_private *tp = netdev_priv(dev);
const int irq = tp->pci_dev->irq;
- disable_irq(irq);
+ disable_irq_nosync(irq);
rtl8139_interrupt(irq, dev);
enable_irq(irq);
}
diff --git a/drivers/net/ethernet/tehuti/tehuti.c b/drivers/net/ethernet/tehuti/tehuti.c
index 61a1540..7edf580 100644
--- a/drivers/net/ethernet/tehuti/tehuti.c
+++ b/drivers/net/ethernet/tehuti/tehuti.c
@@ -1629,13 +1629,8 @@
unsigned long flags;
ENTER;
- local_irq_save(flags);
- if (!spin_trylock(&priv->tx_lock)) {
- local_irq_restore(flags);
- DBG("%s[%s]: TX locked, returning NETDEV_TX_LOCKED\n",
- BDX_DRV_NAME, ndev->name);
- return NETDEV_TX_LOCKED;
- }
+
+ spin_lock_irqsave(&priv->tx_lock, flags);
/* build tx descriptor */
BDX_ASSERT(f->m.wptr >= f->m.memsz); /* started with valid wptr */
diff --git a/drivers/net/rionet.c b/drivers/net/rionet.c
index d93bac1..48be12a 100644
--- a/drivers/net/rionet.c
+++ b/drivers/net/rionet.c
@@ -174,11 +174,7 @@
unsigned long flags;
int add_num = 1;
- local_irq_save(flags);
- if (!spin_trylock(&rnet->tx_lock)) {
- local_irq_restore(flags);
- return NETDEV_TX_LOCKED;
- }
+ spin_lock_irqsave(&rnet->tx_lock, flags);
if (is_multicast_ether_addr(eth->h_dest))
add_num = nets[rnet->mport->id].nact;
diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 67536a2..e10646b 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -1402,6 +1402,20 @@
.set_bits_mask = iwl_trans_pcie_set_bits_mask,
};
+#ifdef CONFIG_PREEMPT_RT_BASE
+static irqreturn_t iwl_rt_irq_handler(int irq, void *dev_id)
+{
+ irqreturn_t ret;
+
+ local_bh_disable();
+ ret = iwl_pcie_isr_ict(irq, dev_id);
+ local_bh_enable();
+ if (ret == IRQ_WAKE_THREAD)
+ ret = iwl_pcie_irq_handler(irq, dev_id);
+ return ret;
+}
+#endif
+
struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
const struct pci_device_id *ent,
const struct iwl_cfg *cfg)
@@ -1520,9 +1534,14 @@
if (iwl_pcie_alloc_ict(trans))
goto out_free_cmd_pool;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ err = request_threaded_irq(pdev->irq, NULL, iwl_rt_irq_handler,
+ IRQF_SHARED | IRQF_ONESHOT, DRV_NAME, trans);
+#else
err = request_threaded_irq(pdev->irq, iwl_pcie_isr_ict,
iwl_pcie_irq_handler,
IRQF_SHARED, DRV_NAME, trans);
+#endif
if (err) {
IWL_ERR(trans, "Error allocating IRQ %d\n", pdev->irq);
goto out_free_ict;
diff --git a/drivers/net/wireless/orinoco/orinoco_usb.c b/drivers/net/wireless/orinoco/orinoco_usb.c
index bdfe637..0fbb1ce 100644
--- a/drivers/net/wireless/orinoco/orinoco_usb.c
+++ b/drivers/net/wireless/orinoco/orinoco_usb.c
@@ -714,7 +714,7 @@
while (!ctx->done.done && msecs--)
udelay(1000);
} else {
- wait_event_interruptible(ctx->done.wait,
+ swait_event_interruptible(ctx->done.wait,
ctx->done.done);
}
break;
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index da26bc8..e12dbf7 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -505,7 +505,7 @@
WARN_ON(!dev->block_cfg_access);
dev->block_cfg_access = 0;
- wake_up_all(&pci_cfg_wait);
+ wake_up_all_locked(&pci_cfg_wait);
raw_spin_unlock_irqrestore(&pci_lock, flags);
}
EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);
diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 07453bb..bd02c14 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -1285,7 +1285,7 @@
struct sk_buff *skb;
#ifdef CONFIG_SMP
struct fcoe_percpu_s *p0;
- unsigned targ_cpu = get_cpu();
+ unsigned targ_cpu = get_cpu_light();
#endif /* CONFIG_SMP */
FCOE_DBG("Destroying receive thread for CPU %d\n", cpu);
@@ -1341,7 +1341,7 @@
kfree_skb(skb);
spin_unlock_bh(&p->fcoe_rx_list.lock);
}
- put_cpu();
+ put_cpu_light();
#else
/*
* This a non-SMP scenario where the singular Rx thread is
@@ -1559,11 +1559,11 @@
static int fcoe_alloc_paged_crc_eof(struct sk_buff *skb, int tlen)
{
struct fcoe_percpu_s *fps;
- int rc;
+ int rc, cpu = get_cpu_light();
- fps = &get_cpu_var(fcoe_percpu);
+ fps = &per_cpu(fcoe_percpu, cpu);
rc = fcoe_get_paged_crc_eof(skb, tlen, fps);
- put_cpu_var(fcoe_percpu);
+ put_cpu_light();
return rc;
}
@@ -1761,11 +1761,11 @@
return 0;
}
- stats = per_cpu_ptr(lport->stats, get_cpu());
+ stats = per_cpu_ptr(lport->stats, get_cpu_light());
stats->InvalidCRCCount++;
if (stats->InvalidCRCCount < 5)
printk(KERN_WARNING "fcoe: dropping frame with CRC error\n");
- put_cpu();
+ put_cpu_light();
return -EINVAL;
}
@@ -1809,7 +1809,7 @@
*/
hp = (struct fcoe_hdr *) skb_network_header(skb);
- stats = per_cpu_ptr(lport->stats, get_cpu());
+ stats = per_cpu_ptr(lport->stats, get_cpu_light());
if (unlikely(FC_FCOE_DECAPS_VER(hp) != FC_FCOE_VER)) {
if (stats->ErrorFrames < 5)
printk(KERN_WARNING "fcoe: FCoE version "
@@ -1841,13 +1841,13 @@
goto drop;
if (!fcoe_filter_frames(lport, fp)) {
- put_cpu();
+ put_cpu_light();
fc_exch_recv(lport, fp);
return;
}
drop:
stats->ErrorFrames++;
- put_cpu();
+ put_cpu_light();
kfree_skb(skb);
}
diff --git a/drivers/scsi/fcoe/fcoe_ctlr.c b/drivers/scsi/fcoe/fcoe_ctlr.c
index 203415e..48769c3 100644
--- a/drivers/scsi/fcoe/fcoe_ctlr.c
+++ b/drivers/scsi/fcoe/fcoe_ctlr.c
@@ -792,7 +792,7 @@
INIT_LIST_HEAD(&del_list);
- stats = per_cpu_ptr(fip->lp->stats, get_cpu());
+ stats = per_cpu_ptr(fip->lp->stats, get_cpu_light());
list_for_each_entry_safe(fcf, next, &fip->fcfs, list) {
deadline = fcf->time + fcf->fka_period + fcf->fka_period / 2;
@@ -828,7 +828,7 @@
sel_time = fcf->time;
}
}
- put_cpu();
+ put_cpu_light();
list_for_each_entry_safe(fcf, next, &del_list, list) {
/* Removes fcf from current list */
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index 5879929..74c7eb0 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -741,10 +741,10 @@
}
memset(ep, 0, sizeof(*ep));
- cpu = get_cpu();
+ cpu = get_cpu_light();
pool = per_cpu_ptr(mp->pool, cpu);
spin_lock_bh(&pool->lock);
- put_cpu();
+ put_cpu_light();
/* peek cache of free slot */
if (pool->left != FC_XID_UNKNOWN) {
diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 83e3ca7..45d449d 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -191,7 +191,7 @@
/* TODO: audit callers to ensure they are ready for qc_issue to
* unconditionally re-enable interrupts
*/
- local_irq_save(flags);
+ local_irq_save_nort(flags);
spin_unlock(ap->lock);
/* If the device fell off, no sense in issuing commands */
@@ -261,7 +261,7 @@
out:
spin_lock(ap->lock);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return ret;
}
diff --git a/drivers/scsi/qla2xxx/qla_inline.h b/drivers/scsi/qla2xxx/qla_inline.h
index 957088b..f8213e1 100644
--- a/drivers/scsi/qla2xxx/qla_inline.h
+++ b/drivers/scsi/qla2xxx/qla_inline.h
@@ -58,12 +58,12 @@
{
unsigned long flags;
struct qla_hw_data *ha = rsp->hw;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
if (IS_P3P_TYPE(ha))
qla82xx_poll(0, rsp);
else
ha->isp_ops->intr_handler(0, rsp);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
static inline uint8_t *
diff --git a/drivers/thermal/x86_pkg_temp_thermal.c b/drivers/thermal/x86_pkg_temp_thermal.c
index 7257366..a1c2318 100644
--- a/drivers/thermal/x86_pkg_temp_thermal.c
+++ b/drivers/thermal/x86_pkg_temp_thermal.c
@@ -29,6 +29,7 @@
#include <linux/pm.h>
#include <linux/thermal.h>
#include <linux/debugfs.h>
+#include <linux/work-simple.h>
#include <asm/cpu_device_id.h>
#include <asm/mce.h>
@@ -352,7 +353,7 @@
}
}
-static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
+static void platform_thermal_notify_work(struct swork_event *event)
{
unsigned long flags;
int cpu = smp_processor_id();
@@ -369,7 +370,7 @@
pkg_work_scheduled[phy_id]) {
disable_pkg_thres_interrupt();
spin_unlock_irqrestore(&pkg_work_lock, flags);
- return -EINVAL;
+ return;
}
pkg_work_scheduled[phy_id] = 1;
spin_unlock_irqrestore(&pkg_work_lock, flags);
@@ -378,9 +379,48 @@
schedule_delayed_work_on(cpu,
&per_cpu(pkg_temp_thermal_threshold_work, cpu),
msecs_to_jiffies(notify_delay_ms));
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static struct swork_event notify_work;
+
+static int thermal_notify_work_init(void)
+{
+ int err;
+
+ err = swork_get();
+ if (err)
+ return err;
+
+ INIT_SWORK(¬ify_work, platform_thermal_notify_work);
return 0;
}
+static void thermal_notify_work_cleanup(void)
+{
+ swork_put();
+}
+
+static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
+{
+ swork_queue(¬ify_work);
+ return 0;
+}
+
+#else /* !CONFIG_PREEMPT_RT_FULL */
+
+static int thermal_notify_work_init(void) { return 0; }
+
+static int thermal_notify_work_cleanup(void) { }
+
+static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
+{
+ platform_thermal_notify_work(NULL);
+
+ return 0;
+}
+#endif /* CONFIG_PREEMPT_RT_FULL */
+
static int find_siblings_cpu(int cpu)
{
int i;
@@ -587,6 +627,9 @@
if (!x86_match_cpu(pkg_temp_thermal_ids))
return -ENODEV;
+ if (!thermal_notify_work_init())
+ return -ENODEV;
+
spin_lock_init(&pkg_work_lock);
platform_thermal_package_notify =
pkg_temp_thermal_platform_thermal_notify;
@@ -611,7 +654,7 @@
kfree(pkg_work_scheduled);
platform_thermal_package_notify = NULL;
platform_thermal_package_rate_control = NULL;
-
+ thermal_notify_work_cleanup();
return -ENODEV;
}
@@ -636,6 +679,7 @@
mutex_unlock(&phy_dev_list_mutex);
platform_thermal_package_notify = NULL;
platform_thermal_package_rate_control = NULL;
+ thermal_notify_work_cleanup();
for_each_online_cpu(i)
cancel_delayed_work_sync(
&per_cpu(pkg_temp_thermal_threshold_work, i));
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index a9eb91c..62fe18e 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -38,6 +38,7 @@
#include <linux/nmi.h>
#include <linux/mutex.h>
#include <linux/slab.h>
+#include <linux/kdb.h>
#ifdef CONFIG_SPARC
#include <linux/sunserialcore.h>
#endif
@@ -80,7 +81,16 @@
#define DEBUG_INTR(fmt...) do { } while (0)
#endif
-#define PASS_LIMIT 512
+/*
+ * On -rt we can have a more delays, and legitimately
+ * so - so don't drop work spuriously and spam the
+ * syslog:
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define PASS_LIMIT 1000000
+#else
+# define PASS_LIMIT 512
+#endif
#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
@@ -2858,14 +2868,10 @@
touch_nmi_watchdog();
- local_irq_save(flags);
- if (port->sysrq) {
- /* serial8250_handle_irq() already took the lock */
- locked = 0;
- } else if (oops_in_progress) {
- locked = spin_trylock(&port->lock);
- } else
- spin_lock(&port->lock);
+ if (port->sysrq || oops_in_progress || in_kdb_printk())
+ locked = spin_trylock_irqsave(&port->lock, flags);
+ else
+ spin_lock_irqsave(&port->lock, flags);
/*
* First save the IER then disable the interrupts
@@ -2897,8 +2903,7 @@
serial8250_modem_status(up);
if (locked)
- spin_unlock(&port->lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&port->lock, flags);
}
static int __init serial8250_console_setup(struct console *co, char *options)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index a976ba9..0cc0f6f 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1916,13 +1916,19 @@
clk_enable(uap->clk);
- local_irq_save(flags);
+ /*
+ * local_irq_save(flags);
+ *
+ * This local_irq_save() is nonsense. If we come in via sysrq
+ * handling then interrupts are already disabled. Aside of
+ * that the port.sysrq check is racy on SMP regardless.
+ */
if (uap->port.sysrq)
locked = 0;
else if (oops_in_progress)
- locked = spin_trylock(&uap->port.lock);
+ locked = spin_trylock_irqsave(&uap->port.lock, flags);
else
- spin_lock(&uap->port.lock);
+ spin_lock_irqsave(&uap->port.lock, flags);
/*
* First save the CR then disable the interrupts
@@ -1944,8 +1950,7 @@
writew(old_cr, uap->port.membase + UART011_CR);
if (locked)
- spin_unlock(&uap->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&uap->port.lock, flags);
clk_disable(uap->clk);
}
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index e2b09fd..59117ea 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1240,13 +1240,10 @@
pm_runtime_get_sync(up->dev);
- local_irq_save(flags);
- if (up->port.sysrq)
- locked = 0;
- else if (oops_in_progress)
- locked = spin_trylock(&up->port.lock);
+ if (up->port.sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&up->port.lock, flags);
else
- spin_lock(&up->port.lock);
+ spin_lock_irqsave(&up->port.lock, flags);
/*
* First save the IER then disable the interrupts
@@ -1275,8 +1272,7 @@
pm_runtime_mark_last_busy(up->dev);
pm_runtime_put_autosuspend(up->dev);
if (locked)
- spin_unlock(&up->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&up->port.lock, flags);
}
static int __init
diff --git a/drivers/tty/serial/sunhv.c b/drivers/tty/serial/sunhv.c
index cf86e72..dc697ce 100644
--- a/drivers/tty/serial/sunhv.c
+++ b/drivers/tty/serial/sunhv.c
@@ -433,13 +433,10 @@
unsigned long flags;
int locked = 1;
- local_irq_save(flags);
- if (port->sysrq) {
- locked = 0;
- } else if (oops_in_progress) {
- locked = spin_trylock(&port->lock);
- } else
- spin_lock(&port->lock);
+ if (port->sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&port->lock, flags);
+ else
+ spin_lock_irqsave(&port->lock, flags);
while (n > 0) {
unsigned long ra = __pa(con_write_page);
@@ -470,8 +467,7 @@
}
if (locked)
- spin_unlock(&port->lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&port->lock, flags);
}
static inline void sunhv_console_putchar(struct uart_port *port, char c)
@@ -492,7 +488,10 @@
unsigned long flags;
int i, locked = 1;
- local_irq_save(flags);
+ if (port->sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&port->lock, flags);
+ else
+ spin_lock_irqsave(&port->lock, flags);
if (port->sysrq) {
locked = 0;
} else if (oops_in_progress) {
@@ -507,8 +506,7 @@
}
if (locked)
- spin_unlock(&port->lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&port->lock, flags);
}
static struct console sunhv_console = {
diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c
index 09c8672..d1773b0 100644
--- a/drivers/tty/serial/sunsab.c
+++ b/drivers/tty/serial/sunsab.c
@@ -853,20 +853,16 @@
unsigned long flags;
int locked = 1;
- local_irq_save(flags);
- if (up->port.sysrq) {
- locked = 0;
- } else if (oops_in_progress) {
- locked = spin_trylock(&up->port.lock);
- } else
- spin_lock(&up->port.lock);
+ if (up->port.sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&up->port.lock, flags);
+ else
+ spin_lock_irqsave(&up->port.lock, flags);
uart_console_write(&up->port, s, n, sunsab_console_putchar);
sunsab_tec_wait(up);
if (locked)
- spin_unlock(&up->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&up->port.lock, flags);
}
static int sunsab_console_setup(struct console *con, char *options)
diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
index c41a5b8..3079c75 100644
--- a/drivers/tty/serial/sunsu.c
+++ b/drivers/tty/serial/sunsu.c
@@ -1295,13 +1295,10 @@
unsigned int ier;
int locked = 1;
- local_irq_save(flags);
- if (up->port.sysrq) {
- locked = 0;
- } else if (oops_in_progress) {
- locked = spin_trylock(&up->port.lock);
- } else
- spin_lock(&up->port.lock);
+ if (up->port.sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&up->port.lock, flags);
+ else
+ spin_lock_irqsave(&up->port.lock, flags);
/*
* First save the UER then disable the interrupts
@@ -1319,8 +1316,7 @@
serial_out(up, UART_IER, ier);
if (locked)
- spin_unlock(&up->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&up->port.lock, flags);
}
/*
diff --git a/drivers/tty/serial/sunzilog.c b/drivers/tty/serial/sunzilog.c
index ed92578..e7e0aad 100644
--- a/drivers/tty/serial/sunzilog.c
+++ b/drivers/tty/serial/sunzilog.c
@@ -1195,20 +1195,16 @@
unsigned long flags;
int locked = 1;
- local_irq_save(flags);
- if (up->port.sysrq) {
- locked = 0;
- } else if (oops_in_progress) {
- locked = spin_trylock(&up->port.lock);
- } else
- spin_lock(&up->port.lock);
+ if (up->port.sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&up->port.lock, flags);
+ else
+ spin_lock_irqsave(&up->port.lock, flags);
uart_console_write(&up->port, s, count, sunzilog_putchar);
udelay(2);
if (locked)
- spin_unlock(&up->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&up->port.lock, flags);
}
static int __init sunzilog_console_setup(struct console *con, char *options)
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 9925e4b..ca8e167 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1680,9 +1680,9 @@
* and no one may trigger the above deadlock situation when
* running complete() in tasklet.
*/
- local_irq_save(flags);
+ local_irq_save_nort(flags);
urb->complete(urb);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
atomic_dec(&urb->use_count);
if (unlikely(atomic_read(&urb->reject)))
@@ -2336,7 +2336,7 @@
* when the first handler doesn't use it. So let's just
* assume it's never used.
*/
- local_irq_save(flags);
+ local_irq_save_nort(flags);
if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
rc = IRQ_NONE;
@@ -2345,7 +2345,7 @@
else
rc = IRQ_HANDLED;
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return rc;
}
EXPORT_SYMBOL_GPL(usb_hcd_irq);
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index c3067f4..32d9183 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -1282,7 +1282,7 @@
pr_info("%s(): freeing\n", __func__);
ffs_data_clear(ffs);
BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
- waitqueue_active(&ffs->ep0req_completion.wait));
+ swaitqueue_active(&ffs->ep0req_completion.wait));
kfree(ffs->dev_name);
kfree(ffs);
}
diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index 8fa7ba0..c6ef916 100644
--- a/drivers/usb/gadget/inode.c
+++ b/drivers/usb/gadget/inode.c
@@ -340,7 +340,7 @@
spin_unlock_irq (&epdata->dev->lock);
if (likely (value == 0)) {
- value = wait_event_interruptible (done.wait, done.done);
+ value = swait_event_interruptible (done.wait, done.done);
if (value != 0) {
spin_lock_irq (&epdata->dev->lock);
if (likely (epdata->ep != NULL)) {
@@ -349,7 +349,7 @@
usb_ep_dequeue (epdata->ep, epdata->req);
spin_unlock_irq (&epdata->dev->lock);
- wait_event (done.wait, done.done);
+ swait_event (done.wait, done.done);
if (epdata->status == -ECONNRESET)
epdata->status = -EINTR;
} else {
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 3770fcb..61acf4c 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -874,9 +874,13 @@
}
if (ints & OHCI_INTR_WDH) {
- spin_lock (&ohci->lock);
- dl_done_list (ohci);
- spin_unlock (&ohci->lock);
+ if (ohci->hcca->done_head == 0) {
+ ints &= ~OHCI_INTR_WDH;
+ } else {
+ spin_lock (&ohci->lock);
+ dl_done_list (ohci);
+ spin_unlock (&ohci->lock);
+ }
}
if (quirk_zfmicro(ohci) && (ints & OHCI_INTR_SF)) {
diff --git a/fs/aio.c b/fs/aio.c
index b37e86c..b9f7f27 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -40,6 +40,7 @@
#include <linux/ramfs.h>
#include <linux/percpu-refcount.h>
#include <linux/mount.h>
+#include <linux/work-simple.h>
#include <asm/kmap_types.h>
#include <asm/uaccess.h>
@@ -115,7 +116,7 @@
struct page **ring_pages;
long nr_pages;
- struct work_struct free_work;
+ struct swork_event free_work;
/*
* signals when all in-flight requests are done
@@ -232,6 +233,7 @@
.mount = aio_mount,
.kill_sb = kill_anon_super,
};
+ BUG_ON(swork_get());
aio_mnt = kern_mount(&aio_fs);
if (IS_ERR(aio_mnt))
panic("Failed to create aio fs mount.");
@@ -511,9 +513,9 @@
return cancel(kiocb);
}
-static void free_ioctx(struct work_struct *work)
+static void free_ioctx(struct swork_event *sev)
{
- struct kioctx *ctx = container_of(work, struct kioctx, free_work);
+ struct kioctx *ctx = container_of(sev, struct kioctx, free_work);
pr_debug("freeing %p\n", ctx);
@@ -530,8 +532,8 @@
if (ctx->rq_wait && atomic_dec_and_test(&ctx->rq_wait->count))
complete(&ctx->rq_wait->comp);
- INIT_WORK(&ctx->free_work, free_ioctx);
- schedule_work(&ctx->free_work);
+ INIT_SWORK(&ctx->free_work, free_ioctx);
+ swork_queue(&ctx->free_work);
}
/*
@@ -539,9 +541,9 @@
* and ctx->users has dropped to 0, so we know no more kiocbs can be submitted -
* now it's safe to cancel any that need to be.
*/
-static void free_ioctx_users(struct percpu_ref *ref)
+static void free_ioctx_users_work(struct swork_event *sev)
{
- struct kioctx *ctx = container_of(ref, struct kioctx, users);
+ struct kioctx *ctx = container_of(sev, struct kioctx, free_work);
struct kiocb *req;
spin_lock_irq(&ctx->ctx_lock);
@@ -560,6 +562,14 @@
percpu_ref_put(&ctx->reqs);
}
+static void free_ioctx_users(struct percpu_ref *ref)
+{
+ struct kioctx *ctx = container_of(ref, struct kioctx, users);
+
+ INIT_SWORK(&ctx->free_work, free_ioctx_users_work);
+ swork_queue(&ctx->free_work);
+}
+
static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
{
unsigned i, new_nr;
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index 3f1128b..c2ed9c4 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -34,6 +34,7 @@
#include <linux/sched.h>
#include <linux/mount.h>
#include <linux/namei.h>
+#include <linux/delay.h>
#include <asm/current.h>
#include <asm/uaccess.h>
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index d096316..b6c6a11 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -157,7 +157,7 @@
parent = p->d_parent;
if (!spin_trylock(&parent->d_lock)) {
spin_unlock(&p->d_lock);
- cpu_relax();
+ cpu_chill();
goto relock;
}
spin_unlock(&p->d_lock);
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 56dea84..e913cb9 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -81,7 +81,7 @@
{
int i;
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
+#if (defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_PREEMPT_RT_BASE))
/* lockdep really cares that we take all of these spinlocks
* in the right order. If any of the locks in the path are not
* currently blocking, it is going to complain. So, make really
@@ -108,7 +108,7 @@
}
}
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
+#if (defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_PREEMPT_RT_BASE))
if (held)
btrfs_clear_lock_blocking_rw(held, held_rw);
#endif
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b3afdde..9ad9c9f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -6899,14 +6899,6 @@
goto again;
}
- if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
- static DEFINE_RATELIMIT_STATE(_rs,
- DEFAULT_RATELIMIT_INTERVAL * 10,
- /*DEFAULT_RATELIMIT_BURST*/ 1);
- if (__ratelimit(&_rs))
- WARN(1, KERN_DEBUG
- "btrfs: block rsv returned %d\n", ret);
- }
try_reserve:
ret = reserve_metadata_bytes(root, block_rsv, blocksize,
BTRFS_RESERVE_NO_FLUSH);
diff --git a/fs/buffer.c b/fs/buffer.c
index 333adbc..fe82b9d 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -322,8 +322,7 @@
* decide that the page is now completely done.
*/
first = page_buffers(page);
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+ flags = bh_uptodate_lock_irqsave(first);
clear_buffer_async_read(bh);
unlock_buffer(bh);
tmp = bh;
@@ -336,8 +335,7 @@
}
tmp = tmp->b_this_page;
} while (tmp != bh);
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
+ bh_uptodate_unlock_irqrestore(first, flags);
/*
* If none of the buffers had errors and they are all
@@ -349,9 +347,7 @@
return;
still_busy:
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
- return;
+ bh_uptodate_unlock_irqrestore(first, flags);
}
/*
@@ -385,8 +381,7 @@
}
first = page_buffers(page);
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+ flags = bh_uptodate_lock_irqsave(first);
clear_buffer_async_write(bh);
unlock_buffer(bh);
@@ -398,15 +393,12 @@
}
tmp = tmp->b_this_page;
}
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
+ bh_uptodate_unlock_irqrestore(first, flags);
end_page_writeback(page);
return;
still_busy:
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
- return;
+ bh_uptodate_unlock_irqrestore(first, flags);
}
EXPORT_SYMBOL(end_buffer_async_write);
@@ -3358,6 +3350,7 @@
struct buffer_head *ret = kmem_cache_zalloc(bh_cachep, gfp_flags);
if (ret) {
INIT_LIST_HEAD(&ret->b_assoc_buffers);
+ buffer_head_init_locks(ret);
preempt_disable();
__this_cpu_inc(bh_accounting.nr);
recalc_bh_state();
diff --git a/fs/dcache.c b/fs/dcache.c
index 9a5e908..96e48d4 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -19,6 +19,7 @@
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/fsnotify.h>
+#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/hash.h>
@@ -470,7 +471,7 @@
static void __dentry_kill(struct dentry *dentry)
{
- struct dentry *parent = NULL;
+struct dentry *parent = NULL;
bool can_free = true;
if (!IS_ROOT(dentry))
parent = dentry->d_parent;
@@ -550,7 +551,7 @@
failed:
spin_unlock(&dentry->d_lock);
- cpu_relax();
+ cpu_chill();
return dentry; /* try again with same dentry */
}
@@ -616,6 +617,8 @@
*/
void dput(struct dentry *dentry)
{
+ struct dentry *parent;
+
if (unlikely(!dentry))
return;
@@ -644,9 +647,20 @@
return;
kill_it:
- dentry = dentry_kill(dentry);
- if (dentry)
+ parent = dentry_kill(dentry);
+ if (parent) {
+ int r;
+
+ if (parent == dentry) {
+ /* the task with the highest priority won't schedule */
+ r = cond_resched();
+ if (!r)
+ cpu_chill();
+ } else {
+ dentry = parent;
+ }
goto repeat;
+ }
}
EXPORT_SYMBOL(dput);
@@ -928,7 +942,7 @@
spin_unlock(&dentry->d_lock);
if (parent)
spin_unlock(&parent->d_lock);
- cpu_relax();
+ cpu_chill();
continue;
}
__dentry_kill(dentry);
@@ -2297,7 +2311,7 @@
if (dentry->d_lockref.count == 1) {
if (!spin_trylock(&inode->i_lock)) {
spin_unlock(&dentry->d_lock);
- cpu_relax();
+ cpu_chill();
goto again;
}
dentry->d_flags &= ~DCACHE_CANT_MOUNT;
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 7585274..5ff7682 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -505,12 +505,12 @@
*/
static void ep_poll_safewake(wait_queue_head_t *wq)
{
- int this_cpu = get_cpu();
+ int this_cpu = get_cpu_light();
ep_call_nested(&poll_safewake_ncalls, EP_MAX_NESTS,
ep_poll_wakeup_proc, NULL, wq, (void *) (long) this_cpu);
- put_cpu();
+ put_cpu_light();
}
static void ep_remove_wait_queue(struct eppoll_entry *pwq)
diff --git a/fs/exec.c b/fs/exec.c
index f33c0ff..00d8ebc 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -841,12 +841,14 @@
}
}
task_lock(tsk);
+ preempt_disable_rt();
active_mm = tsk->active_mm;
tsk->mm = mm;
tsk->active_mm = mm;
activate_mm(active_mm, mm);
tsk->mm->vmacache_seqnum = 0;
vmacache_flush(tsk);
+ preempt_enable_rt();
task_unlock(tsk);
arch_pick_mmap_layout(mm);
if (old_mm) {
diff --git a/fs/jbd/checkpoint.c b/fs/jbd/checkpoint.c
index 08c0304..95debd7 100644
--- a/fs/jbd/checkpoint.c
+++ b/fs/jbd/checkpoint.c
@@ -129,6 +129,8 @@
if (journal->j_flags & JFS_ABORT)
return;
spin_unlock(&journal->j_state_lock);
+ if (current->plug)
+ io_schedule();
mutex_lock(&journal->j_checkpoint_mutex);
/*
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index d4c7e47..f0c3d19 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -125,6 +125,8 @@
if (journal->j_flags & JBD2_ABORT)
return;
write_unlock(&journal->j_state_lock);
+ if (current->plug)
+ io_schedule();
mutex_lock(&journal->j_checkpoint_mutex);
/*
diff --git a/fs/namespace.c b/fs/namespace.c
index f674732..c752a57 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -23,6 +23,7 @@
#include <linux/uaccess.h>
#include <linux/proc_ns.h>
#include <linux/magic.h>
+#include <linux/delay.h>
#include "pnode.h"
#include "internal.h"
@@ -315,8 +316,11 @@
* incremented count after it has set MNT_WRITE_HOLD.
*/
smp_mb();
- while (ACCESS_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD)
- cpu_relax();
+ while (ACCESS_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) {
+ preempt_enable();
+ cpu_chill();
+ preempt_disable();
+ }
/*
* After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will
* be set to match its requirements. So we must not load that until
diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index d267ea6..33f0d86 100644
--- a/fs/ntfs/aops.c
+++ b/fs/ntfs/aops.c
@@ -108,8 +108,7 @@
"0x%llx.", (unsigned long long)bh->b_blocknr);
}
first = page_buffers(page);
- local_irq_save(flags);
- bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+ flags = bh_uptodate_lock_irqsave(first);
clear_buffer_async_read(bh);
unlock_buffer(bh);
tmp = bh;
@@ -124,8 +123,7 @@
}
tmp = tmp->b_this_page;
} while (tmp != bh);
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
+ bh_uptodate_unlock_irqrestore(first, flags);
/*
* If none of the buffers had errors then we can set the page uptodate,
* but we first have to perform the post read mst fixups, if the
@@ -146,13 +144,13 @@
recs = PAGE_CACHE_SIZE / rec_size;
/* Should have been verified before we got here... */
BUG_ON(!recs);
- local_irq_save(flags);
+ local_irq_save_nort(flags);
kaddr = kmap_atomic(page);
for (i = 0; i < recs; i++)
post_read_mst_fixup((NTFS_RECORD*)(kaddr +
i * rec_size), rec_size);
kunmap_atomic(kaddr);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
flush_dcache_page(page);
if (likely(page_uptodate && !PageError(page)))
SetPageUptodate(page);
@@ -160,9 +158,7 @@
unlock_page(page);
return;
still_busy:
- bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
- local_irq_restore(flags);
- return;
+ bh_uptodate_unlock_irqrestore(first, flags);
}
/**
diff --git a/fs/timerfd.c b/fs/timerfd.c
index 9293121..d20e45a 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -380,7 +380,10 @@
break;
}
spin_unlock_irq(&ctx->wqh.lock);
- cpu_relax();
+ if (isalarm(ctx))
+ hrtimer_wait_for_timer(&ctx->t.alarm.timer);
+ else
+ hrtimer_wait_for_timer(&ctx->t.tmr);
}
/*
diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
index f9bb590..8483f8c 100644
--- a/fs/xfs/xfs_linux.h
+++ b/fs/xfs/xfs_linux.h
@@ -131,7 +131,7 @@
/*
* Feature macros (disable/enable)
*/
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) && !defined(CONFIG_PREEMPT_RT_FULL)
#define HAVE_PERCPU_SB /* per cpu superblock counters are a 2.6 feature */
#else
#undef HAVE_PERCPU_SB /* per cpu superblock counters are a 2.6 feature */
diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
index 68534ef..0ef299d 100644
--- a/include/acpi/platform/aclinux.h
+++ b/include/acpi/platform/aclinux.h
@@ -72,6 +72,7 @@
#define acpi_cache_t struct kmem_cache
#define acpi_spinlock spinlock_t *
+#define acpi_raw_spinlock raw_spinlock_t *
#define acpi_cpu_flags unsigned long
#else /* !__KERNEL__ */
@@ -174,6 +175,19 @@
lock ? AE_OK : AE_NO_MEMORY; \
})
+#define acpi_os_create_raw_lock(__handle) \
+({ \
+ raw_spinlock_t *lock = ACPI_ALLOCATE(sizeof(*lock)); \
+ \
+ if (lock) { \
+ *(__handle) = lock; \
+ raw_spin_lock_init(*(__handle)); \
+ } \
+ lock ? AE_OK : AE_NO_MEMORY; \
+})
+
+#define acpi_os_delete_raw_lock(__handle) kfree(__handle)
+
#endif /* __KERNEL__ */
#endif /* __ACLINUX_H__ */
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 7d10f96..aee7fd2 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -202,6 +202,20 @@
# define WARN_ON_SMP(x) ({0;})
#endif
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define BUG_ON_RT(c) BUG_ON(c)
+# define BUG_ON_NONRT(c) do { } while (0)
+# define WARN_ON_RT(condition) WARN_ON(condition)
+# define WARN_ON_NONRT(condition) do { } while (0)
+# define WARN_ON_ONCE_NONRT(condition) do { } while (0)
+#else
+# define BUG_ON_RT(c) do { } while (0)
+# define BUG_ON_NONRT(c) BUG_ON(c)
+# define WARN_ON_RT(condition) do { } while (0)
+# define WARN_ON_NONRT(condition) WARN_ON(condition)
+# define WARN_ON_ONCE_NONRT(condition) WARN_ON_ONCE(condition)
+#endif
+
#endif /* __ASSEMBLY__ */
#endif
diff --git a/include/asm-generic/irq_work.h b/include/asm-generic/irq_work.h
new file mode 100644
index 0000000..a44f452
--- /dev/null
+++ b/include/asm-generic/irq_work.h
@@ -0,0 +1,10 @@
+#ifndef __ASM_IRQ_WORK_H
+#define __ASM_IRQ_WORK_H
+
+static inline bool arch_irq_work_has_interrupt(void)
+{
+ return false;
+}
+
+#endif /* __ASM_IRQ_WORK_H */
+
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index d77797a..cac4973 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -75,8 +75,52 @@
struct address_space *b_assoc_map; /* mapping this buffer is
associated with */
atomic_t b_count; /* users using this buffer_head */
+#ifdef CONFIG_PREEMPT_RT_BASE
+ spinlock_t b_uptodate_lock;
+#if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || \
+ defined(CONFIG_JBD2) || defined(CONFIG_JBD2_MODULE)
+ spinlock_t b_state_lock;
+ spinlock_t b_journal_head_lock;
+#endif
+#endif
};
+static inline unsigned long bh_uptodate_lock_irqsave(struct buffer_head *bh)
+{
+ unsigned long flags;
+
+#ifndef CONFIG_PREEMPT_RT_BASE
+ local_irq_save(flags);
+ bit_spin_lock(BH_Uptodate_Lock, &bh->b_state);
+#else
+ spin_lock_irqsave(&bh->b_uptodate_lock, flags);
+#endif
+ return flags;
+}
+
+static inline void
+bh_uptodate_unlock_irqrestore(struct buffer_head *bh, unsigned long flags)
+{
+#ifndef CONFIG_PREEMPT_RT_BASE
+ bit_spin_unlock(BH_Uptodate_Lock, &bh->b_state);
+ local_irq_restore(flags);
+#else
+ spin_unlock_irqrestore(&bh->b_uptodate_lock, flags);
+#endif
+}
+
+static inline void buffer_head_init_locks(struct buffer_head *bh)
+{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ spin_lock_init(&bh->b_uptodate_lock);
+#if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || \
+ defined(CONFIG_JBD2) || defined(CONFIG_JBD2_MODULE)
+ spin_lock_init(&bh->b_state_lock);
+ spin_lock_init(&bh->b_journal_head_lock);
+#endif
+#endif
+}
+
/*
* macro tricks to expand the set_buffer_foo(), clear_buffer_foo()
* and buffer_foo() functions.
diff --git a/include/linux/completion.h b/include/linux/completion.h
index 3cd574d..eb2d4ac 100644
--- a/include/linux/completion.h
+++ b/include/linux/completion.h
@@ -8,7 +8,7 @@
* See kernel/sched/core.c for details.
*/
-#include <linux/wait.h>
+#include <linux/wait-simple.h>
/*
* struct completion - structure used to maintain state for a "completion"
@@ -24,11 +24,11 @@
*/
struct completion {
unsigned int done;
- wait_queue_head_t wait;
+ struct swait_head wait;
};
#define COMPLETION_INITIALIZER(work) \
- { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
+ { 0, SWAIT_HEAD_INITIALIZER((work).wait) }
#define COMPLETION_INITIALIZER_ONSTACK(work) \
({ init_completion(&work); work; })
@@ -73,7 +73,7 @@
static inline void init_completion(struct completion *x)
{
x->done = 0;
- init_waitqueue_head(&x->wait);
+ init_swait_head(&x->wait);
}
extern void wait_for_completion(struct completion *);
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index d1fcdcb..62bc7b2 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -173,6 +173,8 @@
extern void put_online_cpus(void);
extern void cpu_hotplug_disable(void);
extern void cpu_hotplug_enable(void);
+extern void pin_current_cpu(void);
+extern void unpin_current_cpu(void);
#define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
#define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
@@ -200,6 +202,8 @@
#define put_online_cpus() do { } while (0)
#define cpu_hotplug_disable() do { } while (0)
#define cpu_hotplug_enable() do { } while (0)
+static inline void pin_current_cpu(void) { }
+static inline void unpin_current_cpu(void) { }
#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
/* These aren't inline functions due to a GCC bug. */
#define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
diff --git a/include/linux/delay.h b/include/linux/delay.h
index a6ecb34..37caab3 100644
--- a/include/linux/delay.h
+++ b/include/linux/delay.h
@@ -52,4 +52,10 @@
msleep(seconds * 1000);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+extern void cpu_chill(void);
+#else
+# define cpu_chill() cpu_relax()
+#endif
+
#endif /* defined(_LINUX_DELAY_H) */
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index e68db4d..9b7b934 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -627,6 +627,18 @@
# endif
#endif /* ifndef HAVE_ARCH_CALLER_ADDR */
+static inline unsigned long get_lock_parent_ip(void)
+{
+ unsigned long addr = CALLER_ADDR0;
+
+ if (!in_lock_functions(addr))
+ return addr;
+ addr = CALLER_ADDR1;
+ if (!in_lock_functions(addr))
+ return addr;
+ return CALLER_ADDR2;
+}
+
#ifdef CONFIG_IRQSOFF_TRACER
extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 20aebdb..ab58c33 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -56,6 +56,9 @@
unsigned char flags;
unsigned char preempt_count;
int pid;
+ unsigned short migrate_disable;
+ unsigned short padding;
+ unsigned char preempt_lazy_count;
};
#define FTRACE_MAX_EVENT \
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 7fb31da..821d523 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -7,6 +7,7 @@
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
+#include <linux/sched.h>
#include <asm/cacheflush.h>
@@ -85,32 +86,51 @@
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+#ifndef CONFIG_PREEMPT_RT_FULL
DECLARE_PER_CPU(int, __kmap_atomic_idx);
+#endif
static inline int kmap_atomic_idx_push(void)
{
+#ifndef CONFIG_PREEMPT_RT_FULL
int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
-#ifdef CONFIG_DEBUG_HIGHMEM
+# ifdef CONFIG_DEBUG_HIGHMEM
WARN_ON_ONCE(in_irq() && !irqs_disabled());
BUG_ON(idx > KM_TYPE_NR);
-#endif
+# endif
return idx;
+#else
+ current->kmap_idx++;
+ BUG_ON(current->kmap_idx > KM_TYPE_NR);
+ return current->kmap_idx - 1;
+#endif
}
static inline int kmap_atomic_idx(void)
{
+#ifndef CONFIG_PREEMPT_RT_FULL
return __this_cpu_read(__kmap_atomic_idx) - 1;
+#else
+ return current->kmap_idx - 1;
+#endif
}
static inline void kmap_atomic_idx_pop(void)
{
-#ifdef CONFIG_DEBUG_HIGHMEM
+#ifndef CONFIG_PREEMPT_RT_FULL
+# ifdef CONFIG_DEBUG_HIGHMEM
int idx = __this_cpu_dec_return(__kmap_atomic_idx);
BUG_ON(idx < 0);
-#else
+# else
__this_cpu_dec(__kmap_atomic_idx);
+# endif
+#else
+ current->kmap_idx--;
+# ifdef CONFIG_DEBUG_HIGHMEM
+ BUG_ON(current->kmap_idx < 0);
+# endif
#endif
}
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index d19a5c2..79a7a35 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -111,6 +111,11 @@
enum hrtimer_restart (*function)(struct hrtimer *);
struct hrtimer_clock_base *base;
unsigned long state;
+ struct list_head cb_entry;
+ int irqsafe;
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ ktime_t praecox;
+#endif
#ifdef CONFIG_TIMER_STATS
int start_pid;
void *start_site;
@@ -147,6 +152,7 @@
int index;
clockid_t clockid;
struct timerqueue_head active;
+ struct list_head expired;
ktime_t resolution;
ktime_t (*get_time)(void);
ktime_t softirq_time;
@@ -190,6 +196,9 @@
unsigned long nr_hangs;
ktime_t max_hang_time;
#endif
+#ifdef CONFIG_PREEMPT_RT_BASE
+ wait_queue_head_t wait;
+#endif
struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
};
@@ -385,6 +394,13 @@
return hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
}
+/* Softirq preemption could deadlock timer removal */
+#ifdef CONFIG_PREEMPT_RT_BASE
+ extern void hrtimer_wait_for_timer(const struct hrtimer *timer);
+#else
+# define hrtimer_wait_for_timer(timer) do { cpu_relax(); } while (0)
+#endif
+
/* Query timers: */
extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 871a213..267527b 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -92,10 +92,14 @@
* Each idr_preload() should be matched with an invocation of this
* function. See idr_preload() for details.
*/
+#ifdef CONFIG_PREEMPT_RT_FULL
+void idr_preload_end(void);
+#else
static inline void idr_preload_end(void)
{
preempt_enable();
}
+#endif
/**
* idr_find - return pointer for given id
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 998f4df..a85cceb 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -144,9 +144,16 @@
# define INIT_PERF_EVENTS(tsk)
#endif
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define INIT_TIMER_LIST .posix_timer_list = NULL,
+#else
+# define INIT_TIMER_LIST
+#endif
+
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
# define INIT_VTIME(tsk) \
- .vtime_seqlock = __SEQLOCK_UNLOCKED(tsk.vtime_seqlock), \
+ .vtime_lock = __RAW_SPIN_LOCK_UNLOCKED(tsk.vtime_lock), \
+ .vtime_seq = SEQCNT_ZERO, \
.vtime_snap = 0, \
.vtime_snap_whence = VTIME_SYS,
#else
@@ -208,6 +215,7 @@
.cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \
.pi_lock = __RAW_SPIN_LOCK_UNLOCKED(tsk.pi_lock), \
.timer_slack_ns = 50000, /* 50 usec default slack */ \
+ INIT_TIMER_LIST \
.pids = { \
[PIDTYPE_PID] = INIT_PID_LINK(PIDTYPE_PID), \
[PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID), \
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 623ab2d..5cd89e3 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -58,6 +58,7 @@
* IRQF_NO_THREAD - Interrupt cannot be threaded
* IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
* resume time.
+ * IRQF_NO_SOFTIRQ_CALL - Do not process softirqs in the irq thread context (RT)
*/
#define IRQF_DISABLED 0x00000020
#define IRQF_SHARED 0x00000080
@@ -71,6 +72,7 @@
#define IRQF_FORCE_RESUME 0x00008000
#define IRQF_NO_THREAD 0x00010000
#define IRQF_EARLY_RESUME 0x00020000
+#define IRQF_NO_SOFTIRQ_CALL 0x00040000
#define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
@@ -176,7 +178,7 @@
#ifdef CONFIG_LOCKDEP
# define local_irq_enable_in_hardirq() do { } while (0)
#else
-# define local_irq_enable_in_hardirq() local_irq_enable()
+# define local_irq_enable_in_hardirq() local_irq_enable_nort()
#endif
extern void disable_irq_nosync(unsigned int irq);
@@ -253,6 +255,7 @@
unsigned int irq;
struct kref kref;
struct work_struct work;
+ struct list_head list;
void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
void (*release)(struct kref *ref);
};
@@ -352,9 +355,13 @@
#ifdef CONFIG_IRQ_FORCED_THREADING
+# ifndef CONFIG_PREEMPT_RT_BASE
extern bool force_irqthreads;
+# else
+# define force_irqthreads (true)
+# endif
#else
-#define force_irqthreads (0)
+#define force_irqthreads (false)
#endif
#ifndef __ARCH_SET_SOFTIRQ_PENDING
@@ -410,15 +417,31 @@
void (*action)(struct softirq_action *);
};
+#ifndef CONFIG_PREEMPT_RT_FULL
asmlinkage void do_softirq(void);
asmlinkage void __do_softirq(void);
+static inline void thread_do_softirq(void) { do_softirq(); }
+#else
+extern void thread_do_softirq(void);
+#endif
+
extern void open_softirq(int nr, void (*action)(struct softirq_action *));
extern void softirq_init(void);
extern void __raise_softirq_irqoff(unsigned int nr);
+#ifdef CONFIG_PREEMPT_RT_FULL
+extern void __raise_softirq_irqoff_ksoft(unsigned int nr);
+#else
+static inline void __raise_softirq_irqoff_ksoft(unsigned int nr)
+{
+ __raise_softirq_irqoff(nr);
+}
+#endif
extern void raise_softirq_irqoff(unsigned int nr);
extern void raise_softirq(unsigned int nr);
+extern void softirq_check_pending_idle(void);
+
/* This is the worklist that queues up per-cpu softirq work.
*
* send_remote_sendirq() adds work to these lists, and
@@ -459,8 +482,9 @@
to be executed on some cpu at least once after this.
* If the tasklet is already scheduled, but its execution is still not
started, it will be executed only once.
- * If this tasklet is already running on another CPU (or schedule is called
- from tasklet itself), it is rescheduled for later.
+ * If this tasklet is already running on another CPU, it is rescheduled
+ for later.
+ * Schedule must not be called from the tasklet itself (a lockup occurs)
* Tasklet is strictly serialized wrt itself, but not
wrt another tasklets. If client needs some intertask synchronization,
he makes it with spinlocks.
@@ -485,27 +509,36 @@
enum
{
TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
- TASKLET_STATE_RUN /* Tasklet is running (SMP only) */
+ TASKLET_STATE_RUN, /* Tasklet is running (SMP only) */
+ TASKLET_STATE_PENDING /* Tasklet is pending */
};
-#ifdef CONFIG_SMP
+#define TASKLET_STATEF_SCHED (1 << TASKLET_STATE_SCHED)
+#define TASKLET_STATEF_RUN (1 << TASKLET_STATE_RUN)
+#define TASKLET_STATEF_PENDING (1 << TASKLET_STATE_PENDING)
+
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
static inline int tasklet_trylock(struct tasklet_struct *t)
{
return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
}
+static inline int tasklet_tryunlock(struct tasklet_struct *t)
+{
+ return cmpxchg(&t->state, TASKLET_STATEF_RUN, 0) == TASKLET_STATEF_RUN;
+}
+
static inline void tasklet_unlock(struct tasklet_struct *t)
{
smp_mb__before_clear_bit();
clear_bit(TASKLET_STATE_RUN, &(t)->state);
}
-static inline void tasklet_unlock_wait(struct tasklet_struct *t)
-{
- while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
-}
+extern void tasklet_unlock_wait(struct tasklet_struct *t);
+
#else
#define tasklet_trylock(t) 1
+#define tasklet_tryunlock(t) 1
#define tasklet_unlock_wait(t) do { } while (0)
#define tasklet_unlock(t) do { } while (0)
#endif
@@ -554,17 +587,8 @@
smp_mb();
}
-static inline void tasklet_enable(struct tasklet_struct *t)
-{
- smp_mb__before_atomic_dec();
- atomic_dec(&t->count);
-}
-
-static inline void tasklet_hi_enable(struct tasklet_struct *t)
-{
- smp_mb__before_atomic_dec();
- atomic_dec(&t->count);
-}
+extern void tasklet_enable(struct tasklet_struct *t);
+extern void tasklet_hi_enable(struct tasklet_struct *t);
extern void tasklet_kill(struct tasklet_struct *t);
extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
@@ -596,6 +620,12 @@
tasklet_kill(&ttimer->tasklet);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+extern void softirq_early_init(void);
+#else
+static inline void softirq_early_init(void) { }
+#endif
+
/*
* Autoprobing for irqs:
*
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 896824e..7a08e31 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -70,6 +70,7 @@
* IRQ_MOVE_PCNTXT - Interrupt can be migrated from process context
* IRQ_NESTED_TRHEAD - Interrupt nests into another thread
* IRQ_PER_CPU_DEVID - Dev_id is a per-cpu variable
+ * IRQ_NO_SOFTIRQ_CALL - No softirq processing in the irq thread context (RT)
*/
enum {
IRQ_TYPE_NONE = 0x00000000,
@@ -94,12 +95,14 @@
IRQ_NESTED_THREAD = (1 << 15),
IRQ_NOTHREAD = (1 << 16),
IRQ_PER_CPU_DEVID = (1 << 17),
+ IRQ_NO_SOFTIRQ_CALL = (1 << 18),
};
#define IRQF_MODIFY_MASK \
(IRQ_TYPE_SENSE_MASK | IRQ_NOPROBE | IRQ_NOREQUEST | \
IRQ_NOAUTOEN | IRQ_MOVE_PCNTXT | IRQ_LEVEL | IRQ_NO_BALANCING | \
- IRQ_PER_CPU | IRQ_NESTED_THREAD | IRQ_NOTHREAD | IRQ_PER_CPU_DEVID)
+ IRQ_PER_CPU | IRQ_NESTED_THREAD | IRQ_NOTHREAD | IRQ_PER_CPU_DEVID | \
+ IRQ_NO_SOFTIRQ_CALL)
#define IRQ_NO_BALANCING_MASK (IRQ_PER_CPU | IRQ_NO_BALANCING)
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index 6601702..ccd736e 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -16,6 +16,7 @@
#define IRQ_WORK_BUSY 2UL
#define IRQ_WORK_FLAGS 3UL
#define IRQ_WORK_LAZY 4UL /* Doesn't want IPI, wait for tick */
+#define IRQ_WORK_HARD_IRQ 8UL /* Run hard IRQ context, even on RT */
struct irq_work {
unsigned long flags;
@@ -32,12 +33,21 @@
void irq_work_queue(struct irq_work *work);
void irq_work_run(void);
+void irq_work_tick(void);
void irq_work_sync(struct irq_work *work);
#ifdef CONFIG_IRQ_WORK
+#include <asm/irq_work.h>
+
bool irq_work_needs_cpu(void);
#else
static inline bool irq_work_needs_cpu(void) { return false; }
#endif
+#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
+void irq_work_tick_soft(void);
+#else
+static inline void irq_work_tick_soft(void) { }
+#endif
+
#endif /* _LINUX_IRQ_WORK_H */
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index a7b4b61..6686311 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -56,6 +56,7 @@
unsigned int irqs_unhandled;
atomic_t threads_handled;
int threads_handled_last;
+ u64 random_ip;
raw_spinlock_t lock;
struct cpumask *percpu_enabled;
#ifdef CONFIG_SMP
diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h
index d176d65..0977829 100644
--- a/include/linux/irqflags.h
+++ b/include/linux/irqflags.h
@@ -25,8 +25,6 @@
# define trace_softirqs_enabled(p) ((p)->softirqs_enabled)
# define trace_hardirq_enter() do { current->hardirq_context++; } while (0)
# define trace_hardirq_exit() do { current->hardirq_context--; } while (0)
-# define lockdep_softirq_enter() do { current->softirq_context++; } while (0)
-# define lockdep_softirq_exit() do { current->softirq_context--; } while (0)
# define INIT_TRACE_IRQFLAGS .softirqs_enabled = 1,
#else
# define trace_hardirqs_on() do { } while (0)
@@ -39,9 +37,15 @@
# define trace_softirqs_enabled(p) 0
# define trace_hardirq_enter() do { } while (0)
# define trace_hardirq_exit() do { } while (0)
+# define INIT_TRACE_IRQFLAGS
+#endif
+
+#if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PREEMPT_RT_FULL)
+# define lockdep_softirq_enter() do { current->softirq_context++; } while (0)
+# define lockdep_softirq_exit() do { current->softirq_context--; } while (0)
+#else
# define lockdep_softirq_enter() do { } while (0)
# define lockdep_softirq_exit() do { } while (0)
-# define INIT_TRACE_IRQFLAGS
#endif
#if defined(CONFIG_IRQSOFF_TRACER) || \
@@ -147,4 +151,23 @@
#endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
+/*
+ * local_irq* variants depending on RT/!RT
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define local_irq_disable_nort() do { } while (0)
+# define local_irq_enable_nort() do { } while (0)
+# define local_irq_save_nort(flags) local_save_flags(flags)
+# define local_irq_restore_nort(flags) (void)(flags)
+# define local_irq_disable_rt() local_irq_disable()
+# define local_irq_enable_rt() local_irq_enable()
+#else
+# define local_irq_disable_nort() local_irq_disable()
+# define local_irq_enable_nort() local_irq_enable()
+# define local_irq_save_nort(flags) local_irq_save(flags)
+# define local_irq_restore_nort(flags) local_irq_restore(flags)
+# define local_irq_disable_rt() do { } while (0)
+# define local_irq_enable_rt() do { } while (0)
+#endif
+
#endif
diff --git a/include/linux/jbd_common.h b/include/linux/jbd_common.h
index 3dc5343..a90a6f5 100644
--- a/include/linux/jbd_common.h
+++ b/include/linux/jbd_common.h
@@ -15,32 +15,56 @@
static inline void jbd_lock_bh_state(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_lock(BH_State, &bh->b_state);
+#else
+ spin_lock(&bh->b_state_lock);
+#endif
}
static inline int jbd_trylock_bh_state(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
return bit_spin_trylock(BH_State, &bh->b_state);
+#else
+ return spin_trylock(&bh->b_state_lock);
+#endif
}
static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
return bit_spin_is_locked(BH_State, &bh->b_state);
+#else
+ return spin_is_locked(&bh->b_state_lock);
+#endif
}
static inline void jbd_unlock_bh_state(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_unlock(BH_State, &bh->b_state);
+#else
+ spin_unlock(&bh->b_state_lock);
+#endif
}
static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_lock(BH_JournalHead, &bh->b_state);
+#else
+ spin_lock(&bh->b_journal_head_lock);
+#endif
}
static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_unlock(BH_JournalHead, &bh->b_state);
+#else
+ spin_unlock(&bh->b_journal_head_lock);
+#endif
}
#endif
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index 6fdea81..0320b01 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -49,7 +49,8 @@
#include <linux/types.h>
#include <linux/compiler.h>
-#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
+#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) && \
+ !defined(CONFIG_PREEMPT_BASE)
struct static_key {
atomic_t enabled;
diff --git a/include/linux/kdb.h b/include/linux/kdb.h
index 7f6fe6e..680ad23 100644
--- a/include/linux/kdb.h
+++ b/include/linux/kdb.h
@@ -115,7 +115,7 @@
extern __printf(1, 0) int vkdb_printf(const char *fmt, va_list args);
extern __printf(1, 2) int kdb_printf(const char *, ...);
typedef __printf(1, 2) int (*kdb_printf_t)(const char *, ...);
-
+#define in_kdb_printk() (kdb_trap_printk)
extern void kdb_init(int level);
/* Access to kdb specific polling devices */
@@ -150,6 +150,7 @@
extern int kdb_unregister(char *);
#else /* ! CONFIG_KGDB_KDB */
static inline __printf(1, 2) int kdb_printf(const char *fmt, ...) { return 0; }
+#define in_kdb_printk() (0)
static inline void kdb_init(int level) {}
static inline int kdb_register(char *cmd, kdb_func_t func, char *usage,
char *help, short minlen) { return 0; }
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 11fdfda..30e07e5 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -425,6 +425,7 @@
SYSTEM_HALT,
SYSTEM_POWER_OFF,
SYSTEM_RESTART,
+ SYSTEM_SUSPEND,
} system_state;
#define TAINT_PROPRIETARY_MODULE 0
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 16a92b1..df04aa6 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -234,7 +234,7 @@
int fpu_active;
int guest_fpu_loaded, guest_xcr0_loaded;
- wait_queue_head_t wq;
+ struct swait_head wq;
struct pid *pid;
int sigset_active;
sigset_t sigset;
@@ -669,7 +669,7 @@
}
#endif
-static inline wait_queue_head_t *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu)
+static inline struct swait_head *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu)
{
#ifdef __KVM_HAVE_ARCH_WQP
return vcpu->arch.wqp;
diff --git a/include/linux/lglock.h b/include/linux/lglock.h
index 0d24e93..d2c0d6d 100644
--- a/include/linux/lglock.h
+++ b/include/linux/lglock.h
@@ -42,22 +42,37 @@
#endif
struct lglock {
+#ifndef CONFIG_PREEMPT_RT_FULL
arch_spinlock_t __percpu *lock;
+#else
+ struct rt_mutex __percpu *lock;
+#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lock_class_key lock_key;
struct lockdep_map lock_dep_map;
#endif
};
-#define DEFINE_LGLOCK(name) \
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define DEFINE_LGLOCK(name) \
static DEFINE_PER_CPU(arch_spinlock_t, name ## _lock) \
= __ARCH_SPIN_LOCK_UNLOCKED; \
struct lglock name = { .lock = &name ## _lock }
-#define DEFINE_STATIC_LGLOCK(name) \
+# define DEFINE_STATIC_LGLOCK(name) \
static DEFINE_PER_CPU(arch_spinlock_t, name ## _lock) \
= __ARCH_SPIN_LOCK_UNLOCKED; \
static struct lglock name = { .lock = &name ## _lock }
+#else
+
+# define DEFINE_LGLOCK(name) \
+ static DEFINE_PER_CPU(struct rt_mutex, name ## _lock); \
+ struct lglock name = { .lock = &name ## _lock }
+
+# define DEFINE_STATIC_LGLOCK(name) \
+ static DEFINE_PER_CPU(struct rt_mutex, name ## _lock); \
+ static struct lglock name = { .lock = &name ## _lock }
+#endif
void lg_lock_init(struct lglock *lg, char *name);
void lg_local_lock(struct lglock *lg);
diff --git a/include/linux/list.h b/include/linux/list.h
index 2ece638..2c2cbc1 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -373,6 +373,17 @@
(!list_empty(ptr) ? list_first_entry(ptr, type, member) : NULL)
/**
+ * list_last_entry - get the last element from a list
+ * @ptr: the list head to take the element from.
+ * @type: the type of the struct this is embedded in.
+ * @member: the name of the list_struct within the struct.
+ *
+ * Note, that list is expected to be not empty.
+ */
+#define list_last_entry(ptr, type, member) \
+ list_entry((ptr)->prev, type, member)
+
+/**
* list_next_entry - get the next element in list
* @pos: the type * to cursor
* @member: the name of the list_struct within the struct.
diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
index 2eb8855..017d0f1 100644
--- a/include/linux/list_bl.h
+++ b/include/linux/list_bl.h
@@ -2,6 +2,7 @@
#define _LINUX_LIST_BL_H
#include <linux/list.h>
+#include <linux/spinlock.h>
#include <linux/bit_spinlock.h>
/*
@@ -32,13 +33,24 @@
struct hlist_bl_head {
struct hlist_bl_node *first;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ raw_spinlock_t lock;
+#endif
};
struct hlist_bl_node {
struct hlist_bl_node *next, **pprev;
};
-#define INIT_HLIST_BL_HEAD(ptr) \
- ((ptr)->first = NULL)
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+#define INIT_HLIST_BL_HEAD(h) \
+do { \
+ (h)->first = NULL; \
+ raw_spin_lock_init(&(h)->lock); \
+} while (0)
+#else
+#define INIT_HLIST_BL_HEAD(h) (h)->first = NULL
+#endif
static inline void INIT_HLIST_BL_NODE(struct hlist_bl_node *h)
{
@@ -117,12 +129,26 @@
static inline void hlist_bl_lock(struct hlist_bl_head *b)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_lock(0, (unsigned long *)b);
+#else
+ raw_spin_lock(&b->lock);
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+ __set_bit(0, (unsigned long *)b);
+#endif
+#endif
}
static inline void hlist_bl_unlock(struct hlist_bl_head *b)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
__bit_spin_unlock(0, (unsigned long *)b);
+#else
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+ __clear_bit(0, (unsigned long *)b);
+#endif
+ raw_spin_unlock(&b->lock);
+#endif
}
static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
diff --git a/include/linux/locallock.h b/include/linux/locallock.h
new file mode 100644
index 0000000..015271ff8
--- /dev/null
+++ b/include/linux/locallock.h
@@ -0,0 +1,276 @@
+#ifndef _LINUX_LOCALLOCK_H
+#define _LINUX_LOCALLOCK_H
+
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+# define LL_WARN(cond) WARN_ON(cond)
+#else
+# define LL_WARN(cond) do { } while (0)
+#endif
+
+/*
+ * per cpu lock based substitute for local_irq_*()
+ */
+struct local_irq_lock {
+ spinlock_t lock;
+ struct task_struct *owner;
+ int nestcnt;
+ unsigned long flags;
+};
+
+#define DEFINE_LOCAL_IRQ_LOCK(lvar) \
+ DEFINE_PER_CPU(struct local_irq_lock, lvar) = { \
+ .lock = __SPIN_LOCK_UNLOCKED((lvar).lock) }
+
+#define DECLARE_LOCAL_IRQ_LOCK(lvar) \
+ DECLARE_PER_CPU(struct local_irq_lock, lvar)
+
+#define local_irq_lock_init(lvar) \
+ do { \
+ int __cpu; \
+ for_each_possible_cpu(__cpu) \
+ spin_lock_init(&per_cpu(lvar, __cpu).lock); \
+ } while (0)
+
+/*
+ * spin_lock|trylock|unlock_local flavour that does not migrate disable
+ * used for __local_lock|trylock|unlock where get_local_var/put_local_var
+ * already takes care of the migrate_disable/enable
+ * for CONFIG_PREEMPT_BASE map to the normal spin_* calls.
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define spin_lock_local(lock) rt_spin_lock(lock)
+# define spin_trylock_local(lock) rt_spin_trylock(lock)
+# define spin_unlock_local(lock) rt_spin_unlock(lock)
+#else
+# define spin_lock_local(lock) spin_lock(lock)
+# define spin_trylock_local(lock) spin_trylock(lock)
+# define spin_unlock_local(lock) spin_unlock(lock)
+#endif
+
+static inline void __local_lock(struct local_irq_lock *lv)
+{
+ if (lv->owner != current) {
+ spin_lock_local(&lv->lock);
+ LL_WARN(lv->owner);
+ LL_WARN(lv->nestcnt);
+ lv->owner = current;
+ }
+ lv->nestcnt++;
+}
+
+#define local_lock(lvar) \
+ do { __local_lock(&get_local_var(lvar)); } while (0)
+
+#define local_lock_on(lvar, cpu) \
+ do { __local_lock(&per_cpu(lvar, cpu)); } while (0)
+
+static inline int __local_trylock(struct local_irq_lock *lv)
+{
+ if (lv->owner != current && spin_trylock_local(&lv->lock)) {
+ LL_WARN(lv->owner);
+ LL_WARN(lv->nestcnt);
+ lv->owner = current;
+ lv->nestcnt = 1;
+ return 1;
+ }
+ return 0;
+}
+
+#define local_trylock(lvar) \
+ ({ \
+ int __locked; \
+ __locked = __local_trylock(&get_local_var(lvar)); \
+ if (!__locked) \
+ put_local_var(lvar); \
+ __locked; \
+ })
+
+static inline void __local_unlock(struct local_irq_lock *lv)
+{
+ LL_WARN(lv->nestcnt == 0);
+ LL_WARN(lv->owner != current);
+ if (--lv->nestcnt)
+ return;
+
+ lv->owner = NULL;
+ spin_unlock_local(&lv->lock);
+}
+
+#define local_unlock(lvar) \
+ do { \
+ __local_unlock(&__get_cpu_var(lvar)); \
+ put_local_var(lvar); \
+ } while (0)
+
+#define local_unlock_on(lvar, cpu) \
+ do { __local_unlock(&per_cpu(lvar, cpu)); } while (0)
+
+static inline void __local_lock_irq(struct local_irq_lock *lv)
+{
+ spin_lock_irqsave(&lv->lock, lv->flags);
+ LL_WARN(lv->owner);
+ LL_WARN(lv->nestcnt);
+ lv->owner = current;
+ lv->nestcnt = 1;
+}
+
+#define local_lock_irq(lvar) \
+ do { __local_lock_irq(&get_local_var(lvar)); } while (0)
+
+#define local_lock_irq_on(lvar, cpu) \
+ do { __local_lock_irq(&per_cpu(lvar, cpu)); } while (0)
+
+static inline void __local_unlock_irq(struct local_irq_lock *lv)
+{
+ LL_WARN(!lv->nestcnt);
+ LL_WARN(lv->owner != current);
+ lv->owner = NULL;
+ lv->nestcnt = 0;
+ spin_unlock_irq(&lv->lock);
+}
+
+#define local_unlock_irq(lvar) \
+ do { \
+ __local_unlock_irq(&__get_cpu_var(lvar)); \
+ put_local_var(lvar); \
+ } while (0)
+
+#define local_unlock_irq_on(lvar, cpu) \
+ do { \
+ __local_unlock_irq(&per_cpu(lvar, cpu)); \
+ } while (0)
+
+static inline int __local_lock_irqsave(struct local_irq_lock *lv)
+{
+ if (lv->owner != current) {
+ __local_lock_irq(lv);
+ return 0;
+ } else {
+ lv->nestcnt++;
+ return 1;
+ }
+}
+
+#define local_lock_irqsave(lvar, _flags) \
+ do { \
+ if (__local_lock_irqsave(&get_local_var(lvar))) \
+ put_local_var(lvar); \
+ _flags = __get_cpu_var(lvar).flags; \
+ } while (0)
+
+#define local_lock_irqsave_on(lvar, _flags, cpu) \
+ do { \
+ __local_lock_irqsave(&per_cpu(lvar, cpu)); \
+ _flags = per_cpu(lvar, cpu).flags; \
+ } while (0)
+
+static inline int __local_unlock_irqrestore(struct local_irq_lock *lv,
+ unsigned long flags)
+{
+ LL_WARN(!lv->nestcnt);
+ LL_WARN(lv->owner != current);
+ if (--lv->nestcnt)
+ return 0;
+
+ lv->owner = NULL;
+ spin_unlock_irqrestore(&lv->lock, lv->flags);
+ return 1;
+}
+
+#define local_unlock_irqrestore(lvar, flags) \
+ do { \
+ if (__local_unlock_irqrestore(&__get_cpu_var(lvar), flags)) \
+ put_local_var(lvar); \
+ } while (0)
+
+#define local_unlock_irqrestore_on(lvar, flags, cpu) \
+ do { \
+ __local_unlock_irqrestore(&per_cpu(lvar, cpu), flags); \
+ } while (0)
+
+#define local_spin_trylock_irq(lvar, lock) \
+ ({ \
+ int __locked; \
+ local_lock_irq(lvar); \
+ __locked = spin_trylock(lock); \
+ if (!__locked) \
+ local_unlock_irq(lvar); \
+ __locked; \
+ })
+
+#define local_spin_lock_irq(lvar, lock) \
+ do { \
+ local_lock_irq(lvar); \
+ spin_lock(lock); \
+ } while (0)
+
+#define local_spin_unlock_irq(lvar, lock) \
+ do { \
+ spin_unlock(lock); \
+ local_unlock_irq(lvar); \
+ } while (0)
+
+#define local_spin_lock_irqsave(lvar, lock, flags) \
+ do { \
+ local_lock_irqsave(lvar, flags); \
+ spin_lock(lock); \
+ } while (0)
+
+#define local_spin_unlock_irqrestore(lvar, lock, flags) \
+ do { \
+ spin_unlock(lock); \
+ local_unlock_irqrestore(lvar, flags); \
+ } while (0)
+
+#define get_locked_var(lvar, var) \
+ (*({ \
+ local_lock(lvar); \
+ &__get_cpu_var(var); \
+ }))
+
+#define put_locked_var(lvar, var) local_unlock(lvar);
+
+#define local_lock_cpu(lvar) \
+ ({ \
+ local_lock(lvar); \
+ smp_processor_id(); \
+ })
+
+#define local_unlock_cpu(lvar) local_unlock(lvar)
+
+#else /* PREEMPT_RT_BASE */
+
+#define DEFINE_LOCAL_IRQ_LOCK(lvar) __typeof__(const int) lvar
+#define DECLARE_LOCAL_IRQ_LOCK(lvar) extern __typeof__(const int) lvar
+
+static inline void local_irq_lock_init(int lvar) { }
+
+#define local_lock(lvar) preempt_disable()
+#define local_unlock(lvar) preempt_enable()
+#define local_lock_irq(lvar) local_irq_disable()
+#define local_unlock_irq(lvar) local_irq_enable()
+#define local_lock_irqsave(lvar, flags) local_irq_save(flags)
+#define local_unlock_irqrestore(lvar, flags) local_irq_restore(flags)
+
+#define local_spin_trylock_irq(lvar, lock) spin_trylock_irq(lock)
+#define local_spin_lock_irq(lvar, lock) spin_lock_irq(lock)
+#define local_spin_unlock_irq(lvar, lock) spin_unlock_irq(lock)
+#define local_spin_lock_irqsave(lvar, lock, flags) \
+ spin_lock_irqsave(lock, flags)
+#define local_spin_unlock_irqrestore(lvar, lock, flags) \
+ spin_unlock_irqrestore(lock, flags)
+
+#define get_locked_var(lvar, var) get_cpu_var(var)
+#define put_locked_var(lvar, var) put_cpu_var(var)
+
+#define local_lock_cpu(lvar) get_cpu()
+#define local_unlock_cpu(lvar) put_cpu()
+
+#endif
+
+#endif
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5676a67..d71a062 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1284,27 +1284,59 @@
* overflow into the next struct page (as it might with DEBUG_SPINLOCK).
* When freeing, reset page->mapping so free_pages_check won't complain.
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
+
#define __pte_lockptr(page) &((page)->ptl)
-#define pte_lock_init(_page) do { \
- spin_lock_init(__pte_lockptr(_page)); \
-} while (0)
+
+static inline struct page *pte_lock_init(struct page *page)
+{
+ spin_lock_init(__pte_lockptr(page));
+ return page;
+}
+
#define pte_lock_deinit(page) ((page)->mapping = NULL)
+
+#else /* !PREEMPT_RT_FULL */
+
+/*
+ * On PREEMPT_RT_FULL the spinlock_t's are too large to embed in the
+ * page frame, hence it only has a pointer and we need to dynamically
+ * allocate the lock when we allocate PTE-pages.
+ *
+ * This is an overall win, since only a small fraction of the pages
+ * will be PTE pages under normal circumstances.
+ */
+
+#define __pte_lockptr(page) ((page)->ptl)
+
+extern struct page *pte_lock_init(struct page *page);
+extern void pte_lock_deinit(struct page *page);
+
+#endif /* PREEMPT_RT_FULL */
+
#define pte_lockptr(mm, pmd) ({(void)(mm); __pte_lockptr(pmd_page(*(pmd)));})
#else /* !USE_SPLIT_PTLOCKS */
/*
* We use mm->page_table_lock to guard all pagetable pages of the mm.
*/
-#define pte_lock_init(page) do {} while (0)
+static inline struct page *pte_lock_init(struct page *page) { return page; }
#define pte_lock_deinit(page) do {} while (0)
#define pte_lockptr(mm, pmd) ({(void)(pmd); &(mm)->page_table_lock;})
#endif /* USE_SPLIT_PTLOCKS */
-static inline void pgtable_page_ctor(struct page *page)
+static inline struct page *__pgtable_page_ctor(struct page *page)
{
- pte_lock_init(page);
- inc_zone_page_state(page, NR_PAGETABLE);
+ page = pte_lock_init(page);
+ if (page)
+ inc_zone_page_state(page, NR_PAGETABLE);
+ return page;
}
+#define pgtable_page_ctor(page) \
+do { \
+ page = __pgtable_page_ctor(page); \
+} while (0)
+
static inline void pgtable_page_dtor(struct page *page)
{
pte_lock_deinit(page);
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index b8131e7..a9c83ee 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -11,6 +11,7 @@
#include <linux/completion.h>
#include <linux/cpumask.h>
#include <linux/page-debug-flags.h>
+#include <linux/rcupdate.h>
#include <linux/uprobes.h>
#include <linux/page-flags-layout.h>
#include <asm/page.h>
@@ -142,7 +143,11 @@
* system if PG_buddy is set.
*/
#if USE_SPLIT_PTLOCKS
+# ifndef CONFIG_PREEMPT_RT_FULL
spinlock_t ptl;
+# else
+ spinlock_t *ptl;
+# endif
#endif
struct kmem_cache *slab_cache; /* SL[AU]B: Pointer to slab */
struct page *first_page; /* Compound tail pages */
@@ -444,6 +449,9 @@
bool tlb_flush_pending;
#endif
struct uprobes_state uprobes_state;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ struct rcu_head delayed_drop;
+#endif
};
/* first nid will either be a valid NID or one of these values */
diff --git a/include/linux/module.h b/include/linux/module.h
index 842ef38..874504d 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -397,6 +397,7 @@
struct module *__module_text_address(unsigned long addr);
struct module *__module_address(unsigned long addr);
bool is_module_address(unsigned long addr);
+bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
bool is_module_percpu_address(unsigned long addr);
bool is_module_text_address(unsigned long addr);
@@ -542,6 +543,11 @@
return false;
}
+static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
+{
+ return false;
+}
+
static inline bool is_module_text_address(unsigned long addr)
{
return false;
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index bab49da..79e172a 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -18,6 +18,17 @@
#include <linux/atomic.h>
#include <asm/processor.h>
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
+ , .dep_map = { .name = #lockname }
+#else
+# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
+#endif
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/mutex_rt.h>
+#else
+
/*
* Simple, straightforward mutexes with strict semantics:
*
@@ -99,13 +110,6 @@
static inline void mutex_destroy(struct mutex *lock) {}
#endif
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
- , .dep_map = { .name = #lockname }
-#else
-# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
-#endif
-
#define __MUTEX_INITIALIZER(lockname) \
{ .count = ATOMIC_INIT(1) \
, .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \
@@ -173,6 +177,8 @@
extern int mutex_trylock(struct mutex *lock);
extern void mutex_unlock(struct mutex *lock);
+#endif /* !PREEMPT_RT_FULL */
+
extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
#ifndef arch_mutex_cpu_relax
diff --git a/include/linux/mutex_rt.h b/include/linux/mutex_rt.h
new file mode 100644
index 0000000..e0284ed
--- /dev/null
+++ b/include/linux/mutex_rt.h
@@ -0,0 +1,89 @@
+#ifndef __LINUX_MUTEX_RT_H
+#define __LINUX_MUTEX_RT_H
+
+#ifndef __LINUX_MUTEX_H
+#error "Please include mutex.h"
+#endif
+
+#include <linux/rtmutex.h>
+
+/* FIXME: Just for __lockfunc */
+#include <linux/spinlock.h>
+
+struct mutex {
+ struct rt_mutex lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+};
+
+#define __MUTEX_INITIALIZER(mutexname) \
+ { \
+ .lock = __RT_MUTEX_INITIALIZER(mutexname.lock) \
+ __DEP_MAP_MUTEX_INITIALIZER(mutexname) \
+ }
+
+#define DEFINE_MUTEX(mutexname) \
+ struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
+
+extern void __mutex_do_init(struct mutex *lock, const char *name, struct lock_class_key *key);
+extern void __lockfunc _mutex_lock(struct mutex *lock);
+extern int __lockfunc _mutex_lock_interruptible(struct mutex *lock);
+extern int __lockfunc _mutex_lock_killable(struct mutex *lock);
+extern void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass);
+extern void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock);
+extern int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_trylock(struct mutex *lock);
+extern void __lockfunc _mutex_unlock(struct mutex *lock);
+
+#define mutex_is_locked(l) rt_mutex_is_locked(&(l)->lock)
+#define mutex_lock(l) _mutex_lock(l)
+#define mutex_lock_interruptible(l) _mutex_lock_interruptible(l)
+#define mutex_lock_killable(l) _mutex_lock_killable(l)
+#define mutex_trylock(l) _mutex_trylock(l)
+#define mutex_unlock(l) _mutex_unlock(l)
+
+#ifdef CONFIG_DEBUG_MUTEXES
+#define mutex_destroy(l) rt_mutex_destroy(&(l)->lock)
+#else
+static inline void mutex_destroy(struct mutex *lock) {}
+#endif
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define mutex_lock_nested(l, s) _mutex_lock_nested(l, s)
+# define mutex_lock_interruptible_nested(l, s) \
+ _mutex_lock_interruptible_nested(l, s)
+# define mutex_lock_killable_nested(l, s) \
+ _mutex_lock_killable_nested(l, s)
+
+# define mutex_lock_nest_lock(lock, nest_lock) \
+do { \
+ typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \
+ _mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \
+} while (0)
+
+#else
+# define mutex_lock_nested(l, s) _mutex_lock(l)
+# define mutex_lock_interruptible_nested(l, s) \
+ _mutex_lock_interruptible(l)
+# define mutex_lock_killable_nested(l, s) \
+ _mutex_lock_killable(l)
+# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
+#endif
+
+# define mutex_init(mutex) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ rt_mutex_init(&(mutex)->lock); \
+ __mutex_do_init((mutex), #mutex, &__key); \
+} while (0)
+
+# define __mutex_init(mutex, name, key) \
+do { \
+ rt_mutex_init(&(mutex)->lock); \
+ __mutex_do_init((mutex), name, key); \
+} while (0)
+
+#endif
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0a793dc..32600d9 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1214,7 +1214,7 @@
unsigned char perm_addr[MAX_ADDR_LEN]; /* permanent hw address */
unsigned char addr_assign_type; /* hw address assignment type */
unsigned char addr_len; /* hardware address length */
- unsigned char neigh_priv_len;
+ unsigned short neigh_priv_len;
unsigned short dev_id; /* Used to differentiate devices
* that share the same link
* layer address
@@ -1935,6 +1935,7 @@
unsigned int dropped;
struct sk_buff_head input_pkt_queue;
struct napi_struct backlog;
+ struct sk_buff_head tofree_queue;
#ifdef CONFIG_NET_FLOW_LIMIT
struct sd_flow_limit __rcu *flow_limit;
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 07d6b44..a6a8a4a 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -3,6 +3,7 @@
#include <linux/netdevice.h>
+#include <linux/locallock.h>
#include <uapi/linux/netfilter/x_tables.h>
/**
@@ -295,6 +296,8 @@
*/
DECLARE_PER_CPU(seqcount_t, xt_recseq);
+DECLARE_LOCAL_IRQ_LOCK(xt_write_lock);
+
/**
* xt_write_recseq_begin - start of a write section
*
@@ -309,6 +312,9 @@
{
unsigned int addend;
+ /* RT protection */
+ local_lock(xt_write_lock);
+
/*
* Low order bit of sequence is set if we already
* called xt_write_recseq_begin().
@@ -339,6 +345,7 @@
/* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
smp_wmb();
__this_cpu_add(xt_recseq.sequence, addend);
+ local_unlock(xt_write_lock);
}
/*
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index f3c7c24..5a77fc9 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -86,9 +86,21 @@
#ifdef CONFIG_NETPOLL
static inline bool netpoll_rx_on(struct sk_buff *skb)
{
- struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
+ struct netpoll_info *npinfo;
+ bool ret;
- return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ rcu_read_lock_bh();
+#endif
+
+ npinfo = rcu_dereference_bh(skb->dev->npinfo);
+ ret = npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+ rcu_read_unlock_bh();
+#endif
+
+ return ret;
}
static inline bool netpoll_rx(struct sk_buff *skb)
diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index d14a4c3..2e4414a 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -6,7 +6,7 @@
*
* Alan Cox <Alan.Cox@linux.org>
*/
-
+
#ifndef _LINUX_NOTIFIER_H
#define _LINUX_NOTIFIER_H
#include <linux/errno.h>
@@ -42,9 +42,7 @@
* in srcu_notifier_call_chain(): no cache bounces and no memory barriers.
* As compensation, srcu_notifier_chain_unregister() is rather expensive.
* SRCU notifier chains should be used when the chain will be called very
- * often but notifier_blocks will seldom be removed. Also, SRCU notifier
- * chains are slightly more difficult to use because they require special
- * runtime initialization.
+ * often but notifier_blocks will seldom be removed.
*/
typedef int (*notifier_fn_t)(struct notifier_block *nb,
@@ -88,7 +86,7 @@
(name)->head = NULL; \
} while (0)
-/* srcu_notifier_heads must be initialized and cleaned up dynamically */
+/* srcu_notifier_heads must be cleaned up dynamically */
extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
#define srcu_cleanup_notifier_head(name) \
cleanup_srcu_struct(&(name)->srcu);
@@ -101,7 +99,13 @@
.head = NULL }
#define RAW_NOTIFIER_INIT(name) { \
.head = NULL }
-/* srcu_notifier_heads cannot be initialized statically */
+
+#define SRCU_NOTIFIER_INIT(name, pcpu) \
+ { \
+ .mutex = __MUTEX_INITIALIZER(name.mutex), \
+ .head = NULL, \
+ .srcu = __SRCU_STRUCT_INIT(name.srcu, pcpu), \
+ }
#define ATOMIC_NOTIFIER_HEAD(name) \
struct atomic_notifier_head name = \
@@ -113,6 +117,18 @@
struct raw_notifier_head name = \
RAW_NOTIFIER_INIT(name)
+#define _SRCU_NOTIFIER_HEAD(name, mod) \
+ static DEFINE_PER_CPU(struct srcu_struct_array, \
+ name##_head_srcu_array); \
+ mod struct srcu_notifier_head name = \
+ SRCU_NOTIFIER_INIT(name, name##_head_srcu_array)
+
+#define SRCU_NOTIFIER_HEAD(name) \
+ _SRCU_NOTIFIER_HEAD(name, )
+
+#define SRCU_NOTIFIER_HEAD_STATIC(name) \
+ _SRCU_NOTIFIER_HEAD(name, static)
+
#ifdef __KERNEL__
extern int atomic_notifier_chain_register(struct atomic_notifier_head *nh,
@@ -182,12 +198,12 @@
/*
* Declared notifiers so far. I can imagine quite a few more chains
- * over time (eg laptop power reset chains, reboot chain (to clean
+ * over time (eg laptop power reset chains, reboot chain (to clean
* device units up), device [un]mount chain, module load/unload chain,
- * low memory chain, screenblank chain (for plug in modular screenblankers)
+ * low memory chain, screenblank chain (for plug in modular screenblankers)
* VC switch chains (for loadable kernel svgalib VC switch helpers) etc...
*/
-
+
/* CPU notfiers are defined in include/linux/cpu.h. */
/* netdevice notifiers are defined in include/linux/netdevice.h */
diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index 777a524..ca67e80 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -24,6 +24,9 @@
*/
struct page_cgroup {
unsigned long flags;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ spinlock_t pcg_lock;
+#endif
struct mem_cgroup *mem_cgroup;
};
@@ -74,12 +77,20 @@
* Don't take this lock in IRQ context.
* This lock is for pc->mem_cgroup, USED, MIGRATION
*/
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_lock(PCG_LOCK, &pc->flags);
+#else
+ spin_lock(&pc->pcg_lock);
+#endif
}
static inline void unlock_page_cgroup(struct page_cgroup *pc)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
bit_spin_unlock(PCG_LOCK, &pc->flags);
+#else
+ spin_unlock(&pc->pcg_lock);
+#endif
}
#else /* CONFIG_MEMCG */
@@ -102,6 +113,10 @@
{
}
+static inline void page_cgroup_lock_init(struct page_cgroup *pc)
+{
+}
+
#endif /* CONFIG_MEMCG */
#include <linux/swap.h>
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index c74088a..3e22237 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -48,6 +48,31 @@
preempt_enable(); \
} while (0)
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define get_local_var(var) get_cpu_var(var)
+# define put_local_var(var) put_cpu_var(var)
+# define get_local_ptr(var) get_cpu_ptr(var)
+# define put_local_ptr(var) put_cpu_ptr(var)
+#else
+# define get_local_var(var) (*({ \
+ migrate_disable(); \
+ &__get_cpu_var(var); }))
+
+# define put_local_var(var) do { \
+ (void)&(var); \
+ migrate_enable(); \
+} while (0)
+
+# define get_local_ptr(var) ({ \
+ migrate_disable(); \
+ this_cpu_ptr(var); })
+
+# define put_local_ptr(var) do { \
+ (void)(var); \
+ migrate_enable(); \
+} while (0)
+#endif
+
/* minimum unit size, also is the maximum supported allocation size */
#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
@@ -151,6 +176,7 @@
#endif
extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
+extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
extern bool is_kernel_percpu_address(unsigned long addr);
#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 23705a5..2cc64b7 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -2,6 +2,7 @@
#define _LINUX_PID_H
#include <linux/rcupdate.h>
+#include <linux/atomic.h>
enum pid_type
{
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index f5d4723..c153cf2 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -23,15 +23,38 @@
#define preempt_count() (current_thread_info()->preempt_count)
+#ifdef CONFIG_PREEMPT_LAZY
+#define add_preempt_lazy_count(val) do { preempt_lazy_count() += (val); } while (0)
+#define sub_preempt_lazy_count(val) do { preempt_lazy_count() -= (val); } while (0)
+#define inc_preempt_lazy_count() add_preempt_lazy_count(1)
+#define dec_preempt_lazy_count() sub_preempt_lazy_count(1)
+#define preempt_lazy_count() (current_thread_info()->preempt_lazy_count)
+#else
+#define add_preempt_lazy_count(val) do { } while (0)
+#define sub_preempt_lazy_count(val) do { } while (0)
+#define inc_preempt_lazy_count() do { } while (0)
+#define dec_preempt_lazy_count() do { } while (0)
+#define preempt_lazy_count() (0)
+#endif
+
#ifdef CONFIG_PREEMPT
asmlinkage void preempt_schedule(void);
+# ifdef CONFIG_PREEMPT_LAZY
#define preempt_check_resched() \
do { \
- if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
+ if (unlikely(test_thread_flag(TIF_NEED_RESCHED) || \
+ test_thread_flag(TIF_NEED_RESCHED_LAZY))) \
preempt_schedule(); \
} while (0)
+# else
+#define preempt_check_resched() \
+do { \
+ if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
+ preempt_schedule(); \
+} while (0)
+# endif
#ifdef CONFIG_CONTEXT_TRACKING
@@ -64,17 +87,36 @@
barrier(); \
} while (0)
+#define preempt_lazy_disable() \
+do { \
+ inc_preempt_lazy_count(); \
+ barrier(); \
+} while (0)
+
#define sched_preempt_enable_no_resched() \
do { \
barrier(); \
dec_preempt_count(); \
} while (0)
-#define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+#ifndef CONFIG_PREEMPT_RT_BASE
+# define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+# define preempt_check_resched_rt() barrier()
+#else
+# define preempt_enable_no_resched() preempt_enable()
+# define preempt_check_resched_rt() preempt_check_resched()
+#endif
#define preempt_enable() \
do { \
- preempt_enable_no_resched(); \
+ sched_preempt_enable_no_resched(); \
+ barrier(); \
+ preempt_check_resched(); \
+} while (0)
+
+#define preempt_lazy_enable() \
+do { \
+ dec_preempt_lazy_count(); \
barrier(); \
preempt_check_resched(); \
} while (0)
@@ -123,9 +165,31 @@
#define preempt_disable_notrace() barrier()
#define preempt_enable_no_resched_notrace() barrier()
#define preempt_enable_notrace() barrier()
+#define preempt_check_resched_rt() barrier()
#endif /* CONFIG_PREEMPT_COUNT */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define preempt_disable_rt() preempt_disable()
+# define preempt_enable_rt() preempt_enable()
+# define preempt_disable_nort() barrier()
+# define preempt_enable_nort() barrier()
+# ifdef CONFIG_SMP
+ extern void migrate_disable(void);
+ extern void migrate_enable(void);
+# else /* CONFIG_SMP */
+# define migrate_disable() barrier()
+# define migrate_enable() barrier()
+# endif /* CONFIG_SMP */
+#else
+# define preempt_disable_rt() barrier()
+# define preempt_enable_rt() barrier()
+# define preempt_disable_nort() preempt_disable()
+# define preempt_enable_nort() preempt_enable()
+# define migrate_disable() preempt_disable()
+# define migrate_enable() preempt_enable()
+#endif
+
#ifdef CONFIG_PREEMPT_NOTIFIERS
struct preempt_notifier;
diff --git a/include/linux/preempt_mask.h b/include/linux/preempt_mask.h
index 931bc61..199f278 100644
--- a/include/linux/preempt_mask.h
+++ b/include/linux/preempt_mask.h
@@ -58,7 +58,11 @@
#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
#define NMI_OFFSET (1UL << NMI_SHIFT)
-#define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
+#else
+# define SOFTIRQ_DISABLE_OFFSET (0)
+#endif
#ifndef PREEMPT_ACTIVE
#define PREEMPT_ACTIVE_BITS 1
@@ -71,9 +75,15 @@
#endif
#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
-#define softirq_count() (preempt_count() & SOFTIRQ_MASK)
#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \
| NMI_MASK))
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define softirq_count() (preempt_count() & SOFTIRQ_MASK)
+# define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
+#else
+# define softirq_count() (0UL)
+extern int in_serving_softirq(void);
+#endif
/*
* Are we doing bottom half or hardware interrupt processing?
@@ -84,7 +94,6 @@
#define in_irq() (hardirq_count())
#define in_softirq() (softirq_count())
#define in_interrupt() (irq_count())
-#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
/*
* Are we in NMI context?
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 1864d94..a2d18be 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -101,9 +101,11 @@
extern asmlinkage __printf(1, 2)
void early_printk(const char *fmt, ...);
void early_vprintk(const char *fmt, va_list ap);
+extern void printk_kill(void);
#else
static inline __printf(1, 2) __cold
void early_printk(const char *s, ...) { }
+static inline void printk_kill(void) { }
#endif
#ifdef CONFIG_PRINTK
@@ -137,7 +139,6 @@
#define printk_ratelimit() __printk_ratelimit(__func__)
extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
unsigned int interval_msec);
-
extern int printk_delay_msec;
extern int dmesg_restrict;
extern int kptr_restrict;
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index 1660445..c0df4bc 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -229,6 +229,8 @@
unsigned long first_index, unsigned int max_items);
int radix_tree_preload(gfp_t gfp_mask);
int radix_tree_maybe_preload(gfp_t gfp_mask);
+void radix_tree_preload_end(void);
+
void radix_tree_init(void);
void *radix_tree_tag_set(struct radix_tree_root *root,
unsigned long index, unsigned int tag);
@@ -251,11 +253,6 @@
int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag);
unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item);
-static inline void radix_tree_preload_end(void)
-{
- preempt_enable();
-}
-
/**
* struct radix_tree_iter - radix tree iterator state
*
diff --git a/include/linux/random.h b/include/linux/random.h
index 2300406..780dd41 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -11,7 +11,7 @@
extern void add_device_randomness(const void *, unsigned int);
extern void add_input_randomness(unsigned int type, unsigned int code,
unsigned int value);
-extern void add_interrupt_randomness(int irq, int irq_flags);
+extern void add_interrupt_randomness(int irq, int irq_flags, __u64 ip);
extern void get_random_bytes(void *buf, int nbytes);
extern void get_random_bytes_arch(void *buf, int nbytes);
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 965725f..f45d683 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -128,6 +128,9 @@
#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
+#ifdef CONFIG_PREEMPT_RT_FULL
+#define call_rcu_bh call_rcu
+#else
/**
* call_rcu_bh() - Queue an RCU for invocation after a quicker grace period.
* @head: structure to be used for queueing the RCU updates.
@@ -151,6 +154,7 @@
*/
extern void call_rcu_bh(struct rcu_head *head,
void (*func)(struct rcu_head *head));
+#endif
/**
* call_rcu_sched() - Queue an RCU for invocation after sched grace period.
@@ -190,6 +194,11 @@
* types of kernel builds, the rcu_read_lock() nesting depth is unknowable.
*/
#define rcu_preempt_depth() (current->rcu_read_lock_nesting)
+#ifndef CONFIG_PREEMPT_RT_FULL
+#define sched_rcu_preempt_depth() rcu_preempt_depth()
+#else
+static inline int sched_rcu_preempt_depth(void) { return 0; }
+#endif
#else /* #ifdef CONFIG_PREEMPT_RCU */
@@ -213,6 +222,8 @@
return 0;
}
+#define sched_rcu_preempt_depth() rcu_preempt_depth()
+
#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
/* Internal to kernel */
@@ -362,7 +373,14 @@
* rcu_read_lock_bh_held() is defined out of line to avoid #include-file
* hell.
*/
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline int rcu_read_lock_bh_held(void)
+{
+ return rcu_read_lock_held();
+}
+#else
extern int rcu_read_lock_bh_held(void);
+#endif
/**
* rcu_read_lock_sched_held() - might we be in RCU-sched read-side critical section?
@@ -818,10 +836,14 @@
static inline void rcu_read_lock_bh(void)
{
local_bh_disable();
+#ifdef CONFIG_PREEMPT_RT_FULL
+ rcu_read_lock();
+#else
__acquire(RCU_BH);
rcu_lock_acquire(&rcu_bh_lock_map);
rcu_lockdep_assert(!rcu_is_cpu_idle(),
"rcu_read_lock_bh() used illegally while idle");
+#endif
}
/*
@@ -831,10 +853,14 @@
*/
static inline void rcu_read_unlock_bh(void)
{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ rcu_read_unlock();
+#else
rcu_lockdep_assert(!rcu_is_cpu_idle(),
"rcu_read_unlock_bh() used illegally while idle");
rcu_lock_release(&rcu_bh_lock_map);
__release(RCU_BH);
+#endif
local_bh_enable();
}
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 226169d..91333de 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -44,7 +44,11 @@
rcu_note_context_switch(cpu);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define synchronize_rcu_bh synchronize_rcu
+#else
extern void synchronize_rcu_bh(void);
+#endif
extern void synchronize_sched_expedited(void);
extern void synchronize_rcu_expedited(void);
@@ -72,17 +76,19 @@
}
extern void rcu_barrier(void);
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define rcu_barrier_bh rcu_barrier
+#else
extern void rcu_barrier_bh(void);
+#endif
extern void rcu_barrier_sched(void);
extern unsigned long rcutorture_testseq;
extern unsigned long rcutorture_vernum;
extern long rcu_batches_completed(void);
-extern long rcu_batches_completed_bh(void);
extern long rcu_batches_completed_sched(void);
extern void rcu_force_quiescent_state(void);
-extern void rcu_bh_force_quiescent_state(void);
extern void rcu_sched_force_quiescent_state(void);
extern void exit_rcu(void);
@@ -90,4 +96,12 @@
extern void rcu_scheduler_starting(void);
extern int rcu_scheduler_active __read_mostly;
+#ifndef CONFIG_PREEMPT_RT_FULL
+extern void rcu_bh_force_quiescent_state(void);
+extern long rcu_batches_completed_bh(void);
+#else
+# define rcu_bh_force_quiescent_state rcu_force_quiescent_state
+# define rcu_batches_completed_bh rcu_batches_completed
+#endif
+
#endif /* __LINUX_RCUTREE_H */
diff --git a/include/linux/rtmutex.h b/include/linux/rtmutex.h
index de17134..a9bb104 100644
--- a/include/linux/rtmutex.h
+++ b/include/linux/rtmutex.h
@@ -14,10 +14,14 @@
#include <linux/linkage.h>
#include <linux/plist.h>
-#include <linux/spinlock_types.h>
+#include <linux/spinlock_types_raw.h>
extern int max_lock_depth; /* for sysctl */
+#ifdef CONFIG_DEBUG_MUTEXES
+#include <linux/debug_locks.h>
+#endif
+
/**
* The rt_mutex structure
*
@@ -29,9 +33,10 @@
raw_spinlock_t wait_lock;
struct plist_head wait_list;
struct task_struct *owner;
-#ifdef CONFIG_DEBUG_RT_MUTEXES
int save_state;
- const char *name, *file;
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+ const char *file;
+ const char *name;
int line;
void *magic;
#endif
@@ -56,19 +61,39 @@
#ifdef CONFIG_DEBUG_RT_MUTEXES
# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
, .name = #mutexname, .file = __FILE__, .line = __LINE__
-# define rt_mutex_init(mutex) __rt_mutex_init(mutex, __func__)
+
+# define rt_mutex_init(mutex) \
+ do { \
+ raw_spin_lock_init(&(mutex)->wait_lock); \
+ __rt_mutex_init(mutex, #mutex); \
+ } while (0)
+
extern void rt_mutex_debug_task_free(struct task_struct *tsk);
#else
# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
-# define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL)
+
+# define rt_mutex_init(mutex) \
+ do { \
+ raw_spin_lock_init(&(mutex)->wait_lock); \
+ __rt_mutex_init(mutex, #mutex); \
+ } while (0)
+
# define rt_mutex_debug_task_free(t) do { } while (0)
#endif
-#define __RT_MUTEX_INITIALIZER(mutexname) \
- { .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
+#define __RT_MUTEX_INITIALIZER_PLAIN(mutexname) \
+ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
, .wait_list = PLIST_HEAD_INIT(mutexname.wait_list) \
, .owner = NULL \
- __DEBUG_RT_MUTEX_INITIALIZER(mutexname)}
+ __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
+
+
+#define __RT_MUTEX_INITIALIZER(mutexname) \
+ { __RT_MUTEX_INITIALIZER_PLAIN(mutexname) }
+
+#define __RT_MUTEX_INITIALIZER_SAVE_STATE(mutexname) \
+ { __RT_MUTEX_INITIALIZER_PLAIN(mutexname) \
+ , .save_state = 1 }
#define DEFINE_RT_MUTEX(mutexname) \
struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
@@ -88,11 +113,10 @@
extern void rt_mutex_destroy(struct rt_mutex *lock);
extern void rt_mutex_lock(struct rt_mutex *lock);
-extern int rt_mutex_lock_interruptible(struct rt_mutex *lock,
- int detect_deadlock);
+extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
+extern int rt_mutex_lock_killable(struct rt_mutex *lock);
extern int rt_mutex_timed_lock(struct rt_mutex *lock,
- struct hrtimer_sleeper *timeout,
- int detect_deadlock);
+ struct hrtimer_sleeper *timeout);
extern int rt_mutex_trylock(struct rt_mutex *lock);
diff --git a/include/linux/rwlock_rt.h b/include/linux/rwlock_rt.h
new file mode 100644
index 0000000..49ed2d4
--- /dev/null
+++ b/include/linux/rwlock_rt.h
@@ -0,0 +1,99 @@
+#ifndef __LINUX_RWLOCK_RT_H
+#define __LINUX_RWLOCK_RT_H
+
+#ifndef __LINUX_SPINLOCK_H
+#error Do not include directly. Use spinlock.h
+#endif
+
+#define rwlock_init(rwl) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ rt_mutex_init(&(rwl)->lock); \
+ __rt_rwlock_init(rwl, #rwl, &__key); \
+} while (0)
+
+extern void __lockfunc rt_write_lock(rwlock_t *rwlock);
+extern void __lockfunc rt_read_lock(rwlock_t *rwlock);
+extern int __lockfunc rt_write_trylock(rwlock_t *rwlock);
+extern int __lockfunc rt_write_trylock_irqsave(rwlock_t *trylock, unsigned long *flags);
+extern int __lockfunc rt_read_trylock(rwlock_t *rwlock);
+extern void __lockfunc rt_write_unlock(rwlock_t *rwlock);
+extern void __lockfunc rt_read_unlock(rwlock_t *rwlock);
+extern unsigned long __lockfunc rt_write_lock_irqsave(rwlock_t *rwlock);
+extern unsigned long __lockfunc rt_read_lock_irqsave(rwlock_t *rwlock);
+extern void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key);
+
+#define read_trylock(lock) __cond_lock(lock, rt_read_trylock(lock))
+#define write_trylock(lock) __cond_lock(lock, rt_write_trylock(lock))
+
+#define write_trylock_irqsave(lock, flags) \
+ __cond_lock(lock, rt_write_trylock_irqsave(lock, &flags))
+
+#define read_lock_irqsave(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = rt_read_lock_irqsave(lock); \
+ } while (0)
+
+#define write_lock_irqsave(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = rt_write_lock_irqsave(lock); \
+ } while (0)
+
+#define read_lock(lock) rt_read_lock(lock)
+
+#define read_lock_bh(lock) \
+ do { \
+ local_bh_disable(); \
+ rt_read_lock(lock); \
+ } while (0)
+
+#define read_lock_irq(lock) read_lock(lock)
+
+#define write_lock(lock) rt_write_lock(lock)
+
+#define write_lock_bh(lock) \
+ do { \
+ local_bh_disable(); \
+ rt_write_lock(lock); \
+ } while (0)
+
+#define write_lock_irq(lock) write_lock(lock)
+
+#define read_unlock(lock) rt_read_unlock(lock)
+
+#define read_unlock_bh(lock) \
+ do { \
+ rt_read_unlock(lock); \
+ local_bh_enable(); \
+ } while (0)
+
+#define read_unlock_irq(lock) read_unlock(lock)
+
+#define write_unlock(lock) rt_write_unlock(lock)
+
+#define write_unlock_bh(lock) \
+ do { \
+ rt_write_unlock(lock); \
+ local_bh_enable(); \
+ } while (0)
+
+#define write_unlock_irq(lock) write_unlock(lock)
+
+#define read_unlock_irqrestore(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ (void) flags; \
+ rt_read_unlock(lock); \
+ } while (0)
+
+#define write_unlock_irqrestore(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ (void) flags; \
+ rt_write_unlock(lock); \
+ } while (0)
+
+#endif
diff --git a/include/linux/rwlock_types.h b/include/linux/rwlock_types.h
index cc0072e..d0da966 100644
--- a/include/linux/rwlock_types.h
+++ b/include/linux/rwlock_types.h
@@ -1,6 +1,10 @@
#ifndef __LINUX_RWLOCK_TYPES_H
#define __LINUX_RWLOCK_TYPES_H
+#if !defined(__LINUX_SPINLOCK_TYPES_H)
+# error "Do not include directly, include spinlock_types.h"
+#endif
+
/*
* include/linux/rwlock_types.h - generic rwlock type definitions
* and initializers
@@ -43,6 +47,7 @@
RW_DEP_MAP_INIT(lockname) }
#endif
-#define DEFINE_RWLOCK(x) rwlock_t x = __RW_LOCK_UNLOCKED(x)
+#define DEFINE_RWLOCK(name) \
+ rwlock_t name __cacheline_aligned_in_smp = __RW_LOCK_UNLOCKED(name)
#endif /* __LINUX_RWLOCK_TYPES_H */
diff --git a/include/linux/rwlock_types_rt.h b/include/linux/rwlock_types_rt.h
new file mode 100644
index 0000000..b138321
--- /dev/null
+++ b/include/linux/rwlock_types_rt.h
@@ -0,0 +1,33 @@
+#ifndef __LINUX_RWLOCK_TYPES_RT_H
+#define __LINUX_RWLOCK_TYPES_RT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+/*
+ * rwlocks - rtmutex which allows single reader recursion
+ */
+typedef struct {
+ struct rt_mutex lock;
+ int read_depth;
+ unsigned int break_lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+} rwlock_t;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define RW_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname }
+#else
+# define RW_DEP_MAP_INIT(lockname)
+#endif
+
+#define __RW_LOCK_UNLOCKED(name) \
+ { .lock = __RT_MUTEX_INITIALIZER_SAVE_STATE(name.lock), \
+ RW_DEP_MAP_INIT(name) }
+
+#define DEFINE_RWLOCK(name) \
+ rwlock_t name __cacheline_aligned_in_smp = __RW_LOCK_UNLOCKED(name)
+
+#endif
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 0616ffe..0ad6070 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -16,6 +16,10 @@
#include <linux/atomic.h>
+#ifdef CONFIG_PREEMPT_RT_FULL
+#include <linux/rwsem_rt.h>
+#else /* PREEMPT_RT_FULL */
+
struct rw_semaphore;
#ifdef CONFIG_RWSEM_GENERIC_SPINLOCK
@@ -149,4 +153,6 @@
# define up_read_non_owner(sem) up_read(sem)
#endif
+#endif /* !PREEMPT_RT_FULL */
+
#endif /* _LINUX_RWSEM_H */
diff --git a/include/linux/rwsem_rt.h b/include/linux/rwsem_rt.h
new file mode 100644
index 0000000..e94d945
--- /dev/null
+++ b/include/linux/rwsem_rt.h
@@ -0,0 +1,128 @@
+#ifndef _LINUX_RWSEM_RT_H
+#define _LINUX_RWSEM_RT_H
+
+#ifndef _LINUX_RWSEM_H
+#error "Include rwsem.h"
+#endif
+
+/*
+ * RW-semaphores are a spinlock plus a reader-depth count.
+ *
+ * Note that the semantics are different from the usual
+ * Linux rw-sems, in PREEMPT_RT mode we do not allow
+ * multiple readers to hold the lock at once, we only allow
+ * a read-lock owner to read-lock recursively. This is
+ * better for latency, makes the implementation inherently
+ * fair and makes it simpler as well.
+ */
+
+#include <linux/rtmutex.h>
+
+struct rw_semaphore {
+ struct rt_mutex lock;
+ int read_depth;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+};
+
+#define __RWSEM_INITIALIZER(name) \
+ { .lock = __RT_MUTEX_INITIALIZER(name.lock), \
+ RW_DEP_MAP_INIT(name) }
+
+#define DECLARE_RWSEM(lockname) \
+ struct rw_semaphore lockname = __RWSEM_INITIALIZER(lockname)
+
+extern void __rt_rwsem_init(struct rw_semaphore *rwsem, const char *name,
+ struct lock_class_key *key);
+
+#define __rt_init_rwsem(sem, name, key) \
+ do { \
+ rt_mutex_init(&(sem)->lock); \
+ __rt_rwsem_init((sem), (name), (key));\
+ } while (0)
+
+#define __init_rwsem(sem, name, key) __rt_init_rwsem(sem, name, key)
+
+# define rt_init_rwsem(sem) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ __rt_init_rwsem((sem), #sem, &__key); \
+} while (0)
+
+extern void rt_down_write(struct rw_semaphore *rwsem);
+extern void rt_down_read_nested(struct rw_semaphore *rwsem, int subclass);
+extern void rt_down_write_nested(struct rw_semaphore *rwsem, int subclass);
+extern void rt_down_write_nested_lock(struct rw_semaphore *rwsem,
+ struct lockdep_map *nest);
+extern void rt_down_read(struct rw_semaphore *rwsem);
+extern int rt_down_write_trylock(struct rw_semaphore *rwsem);
+extern int rt_down_read_trylock(struct rw_semaphore *rwsem);
+extern void rt_up_read(struct rw_semaphore *rwsem);
+extern void rt_up_write(struct rw_semaphore *rwsem);
+extern void rt_downgrade_write(struct rw_semaphore *rwsem);
+
+#define init_rwsem(sem) rt_init_rwsem(sem)
+#define rwsem_is_locked(s) rt_mutex_is_locked(&(s)->lock)
+
+static inline void down_read(struct rw_semaphore *sem)
+{
+ rt_down_read(sem);
+}
+
+static inline int down_read_trylock(struct rw_semaphore *sem)
+{
+ return rt_down_read_trylock(sem);
+}
+
+static inline void down_write(struct rw_semaphore *sem)
+{
+ rt_down_write(sem);
+}
+
+static inline int down_write_trylock(struct rw_semaphore *sem)
+{
+ return rt_down_write_trylock(sem);
+}
+
+static inline void up_read(struct rw_semaphore *sem)
+{
+ rt_up_read(sem);
+}
+
+static inline void up_write(struct rw_semaphore *sem)
+{
+ rt_up_write(sem);
+}
+
+static inline void downgrade_write(struct rw_semaphore *sem)
+{
+ rt_downgrade_write(sem);
+}
+
+static inline void down_read_nested(struct rw_semaphore *sem, int subclass)
+{
+ return rt_down_read_nested(sem, subclass);
+}
+
+static inline void down_write_nested(struct rw_semaphore *sem, int subclass)
+{
+ rt_down_write_nested(sem, subclass);
+}
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static inline void down_write_nest_lock(struct rw_semaphore *sem,
+ struct rw_semaphore *nest_lock)
+{
+ rt_down_write_nested_lock(sem, &nest_lock->dep_map);
+}
+
+#else
+
+static inline void down_write_nest_lock(struct rw_semaphore *sem,
+ struct rw_semaphore *nest_lock)
+{
+ rt_down_write_nested_lock(sem, NULL);
+}
+#endif
+#endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2bc93e2..afdd885 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -23,6 +23,7 @@
#include <linux/nodemask.h>
#include <linux/mm_types.h>
+#include <asm/kmap_types.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/cputime.h>
@@ -52,6 +53,7 @@
#include <linux/llist.h>
#include <linux/uidgid.h>
#include <linux/gfp.h>
+#include <linux/hardirq.h>
#include <asm/processor.h>
@@ -111,8 +113,6 @@
extern void calc_global_load(unsigned long ticks);
extern void update_cpu_load_nohz(void);
-extern unsigned long get_parent_ip(unsigned long addr);
-
extern void dump_cpu_task(int cpu);
struct seq_file;
@@ -169,11 +169,8 @@
TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
__TASK_TRACED)
-#define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
#define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
#define task_is_dead(task) ((task)->exit_state != 0)
-#define task_is_stopped_or_traced(task) \
- ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
#define task_contributes_to_load(task) \
((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
(task->flags & PF_FROZEN) == 0)
@@ -1029,6 +1026,7 @@
struct task_struct {
volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
+ volatile long saved_state; /* saved state for "spinlock sleepers" */
void *stack;
atomic_t usage;
unsigned int flags; /* per process flags, defined below */
@@ -1071,6 +1069,12 @@
#endif
unsigned int policy;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ int migrate_disable;
+# ifdef CONFIG_SCHED_DEBUG
+ int migrate_disable_atomic;
+# endif
+#endif
int nr_cpus_allowed;
cpumask_t cpus_allowed;
@@ -1170,7 +1174,8 @@
struct cputime prev_cputime;
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
- seqlock_t vtime_seqlock;
+ raw_spinlock_t vtime_lock;
+ seqcount_t vtime_seq;
unsigned long long vtime_snap;
enum {
VTIME_SLEEPING = 0,
@@ -1186,6 +1191,9 @@
struct task_cputime cputime_expires;
struct list_head cpu_timers[3];
+#ifdef CONFIG_PREEMPT_RT_BASE
+ struct task_struct *posix_timer_list;
+#endif
/* process credentials */
const struct cred __rcu *real_cred; /* objective and real subjective task
@@ -1217,10 +1225,15 @@
/* signal handlers */
struct signal_struct *signal;
struct sighand_struct *sighand;
+ struct sigqueue *sigqueue_cache;
sigset_t blocked, real_blocked;
sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
struct sigpending pending;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /* TODO: move me into ->restart_block ? */
+ struct siginfo forced_info;
+#endif
unsigned long sas_ss_sp;
size_t sas_ss_size;
@@ -1257,6 +1270,9 @@
/* mutex deadlock detection */
struct mutex_waiter *blocked_on;
#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+ int pagefault_disabled;
+#endif
#ifdef CONFIG_TRACE_IRQFLAGS
unsigned int irq_events;
unsigned long hardirq_enable_ip;
@@ -1332,6 +1348,9 @@
struct mutex perf_event_mutex;
struct list_head perf_event_list;
#endif
+#ifdef CONFIG_DEBUG_PREEMPT
+ unsigned long preempt_disable_ip;
+#endif
#ifdef CONFIG_NUMA
struct mempolicy *mempolicy; /* Protected by alloc_lock */
short il_next;
@@ -1399,6 +1418,12 @@
unsigned long trace;
/* bitmask and counter of trace recursion */
unsigned long trace_recursion;
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ u64 preempt_timestamp_hist;
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ long timer_offset;
+#endif
+#endif
#endif /* CONFIG_TRACING */
#ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
struct memcg_batch_info {
@@ -1422,11 +1447,19 @@
unsigned int sequential_io;
unsigned int sequential_io_avg;
#endif
+#ifdef CONFIG_PREEMPT_RT_BASE
+ struct rcu_head put_rcu;
+ int softirq_nestcnt;
+ unsigned int softirqs_raised;
+#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+# if defined CONFIG_HIGHMEM || defined CONFIG_X86_32
+ int kmap_idx;
+ pte_t kmap_pte[KM_TYPE_NR];
+# endif
+#endif
};
-/* Future-safe accessor for struct task_struct's cpus_allowed. */
-#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
-
#ifdef CONFIG_NUMA_BALANCING
extern void task_numa_fault(int node, int pages, bool migrated);
extern void set_numabalancing_state(bool enabled);
@@ -1439,6 +1472,17 @@
}
#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline bool cur_pf_disabled(void) { return current->pagefault_disabled; }
+#else
+static inline bool cur_pf_disabled(void) { return false; }
+#endif
+
+static inline bool pagefault_disabled(void)
+{
+ return in_atomic() || cur_pf_disabled();
+}
+
static inline struct pid *task_pid(struct task_struct *task)
{
return task->pids[PIDTYPE_PID].pid;
@@ -1592,6 +1636,15 @@
extern void free_task(struct task_struct *tsk);
#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
+#ifdef CONFIG_PREEMPT_RT_BASE
+extern void __put_task_struct_cb(struct rcu_head *rhp);
+
+static inline void put_task_struct(struct task_struct *t)
+{
+ if (atomic_dec_and_test(&t->usage))
+ call_rcu(&t->put_rcu, __put_task_struct_cb);
+}
+#else
extern void __put_task_struct(struct task_struct *t);
static inline void put_task_struct(struct task_struct *t)
@@ -1599,6 +1652,7 @@
if (atomic_dec_and_test(&t->usage))
__put_task_struct(t);
}
+#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
extern void task_cputime(struct task_struct *t,
@@ -1637,6 +1691,7 @@
/*
* Per process flags
*/
+#define PF_IN_SOFTIRQ 0x00000001 /* Task is serving softirq */
#define PF_EXITING 0x00000004 /* getting shut down */
#define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */
#define PF_VCPU 0x00000010 /* I'm a virtual CPU */
@@ -1784,6 +1839,10 @@
extern int set_cpus_allowed_ptr(struct task_struct *p,
const struct cpumask *new_mask);
+int migrate_me(void);
+void tell_sched_cpu_down_begin(int cpu);
+void tell_sched_cpu_down_done(int cpu);
+
#else
static inline void do_set_cpus_allowed(struct task_struct *p,
const struct cpumask *new_mask)
@@ -1796,6 +1855,9 @@
return -EINVAL;
return 0;
}
+static inline int migrate_me(void) { return 0; }
+static inline void tell_sched_cpu_down_begin(int cpu) { }
+static inline void tell_sched_cpu_down_done(int cpu) { }
#endif
#ifdef CONFIG_NO_HZ_COMMON
@@ -2003,6 +2065,7 @@
extern int wake_up_state(struct task_struct *tsk, unsigned int state);
extern int wake_up_process(struct task_struct *tsk);
+extern int wake_up_lock_sleeper(struct task_struct * tsk);
extern void wake_up_new_task(struct task_struct *tsk);
#ifdef CONFIG_SMP
extern void kick_process(struct task_struct *tsk);
@@ -2117,12 +2180,24 @@
/* mmdrop drops the mm and the page tables */
extern void __mmdrop(struct mm_struct *);
+
static inline void mmdrop(struct mm_struct * mm)
{
if (unlikely(atomic_dec_and_test(&mm->mm_count)))
__mmdrop(mm);
}
+#ifdef CONFIG_PREEMPT_RT_BASE
+extern void __mmdrop_delayed(struct rcu_head *rhp);
+static inline void mmdrop_delayed(struct mm_struct *mm)
+{
+ if (atomic_dec_and_test(&mm->mm_count))
+ call_rcu(&mm->delayed_drop, __mmdrop_delayed);
+}
+#else
+# define mmdrop_delayed(mm) mmdrop(mm)
+#endif
+
/* mmput gets rid of the mappings and all user-space */
extern void mmput(struct mm_struct *);
/* Grab a reference to a task's mm, if it is not already going away */
@@ -2415,6 +2490,52 @@
return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
}
+#ifdef CONFIG_PREEMPT_LAZY
+static inline void set_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+ set_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY);
+}
+
+static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+ clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY);
+}
+
+static inline int test_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+ return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY));
+}
+
+static inline int need_resched_lazy(void)
+{
+ return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+}
+
+static inline int need_resched_now(void)
+{
+ return test_thread_flag(TIF_NEED_RESCHED);
+}
+
+static inline int need_resched(void)
+{
+ return test_thread_flag(TIF_NEED_RESCHED) ||
+ test_thread_flag(TIF_NEED_RESCHED_LAZY);
+}
+#else
+static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk) { }
+static inline int need_resched_lazy(void) { return 0; }
+
+static inline int need_resched_now(void)
+{
+ return test_thread_flag(TIF_NEED_RESCHED);
+}
+
+static inline int need_resched(void)
+{
+ return test_thread_flag(TIF_NEED_RESCHED);
+}
+#endif
+
static inline int restart_syscall(void)
{
set_tsk_thread_flag(current, TIF_SIGPENDING);
@@ -2446,9 +2567,49 @@
return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
}
-static inline int need_resched(void)
+static inline bool __task_is_stopped_or_traced(struct task_struct *task)
{
- return unlikely(test_thread_flag(TIF_NEED_RESCHED));
+ if (task->state & (__TASK_STOPPED | __TASK_TRACED))
+ return true;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (task->saved_state & (__TASK_STOPPED | __TASK_TRACED))
+ return true;
+#endif
+ return false;
+}
+
+static inline bool task_is_stopped_or_traced(struct task_struct *task)
+{
+ bool traced_stopped;
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+ traced_stopped = __task_is_stopped_or_traced(task);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+#else
+ traced_stopped = __task_is_stopped_or_traced(task);
+#endif
+ return traced_stopped;
+}
+
+static inline bool task_is_traced(struct task_struct *task)
+{
+ bool traced = false;
+
+ if (task->state & __TASK_TRACED)
+ return true;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /* in case the task is sleeping on tasklist_lock */
+ raw_spin_lock_irq(&task->pi_lock);
+ if (task->state & __TASK_TRACED)
+ traced = true;
+ else if (task->saved_state & __TASK_TRACED)
+ traced = true;
+ raw_spin_unlock_irq(&task->pi_lock);
+#endif
+ return traced;
}
/*
@@ -2467,7 +2628,7 @@
extern int __cond_resched_lock(spinlock_t *lock);
-#ifdef CONFIG_PREEMPT_COUNT
+#if defined(CONFIG_PREEMPT_COUNT) && !defined(CONFIG_PREEMPT_RT_FULL)
#define PREEMPT_LOCK_OFFSET PREEMPT_OFFSET
#else
#define PREEMPT_LOCK_OFFSET 0
@@ -2478,12 +2639,16 @@
__cond_resched_lock(lock); \
})
+#ifndef CONFIG_PREEMPT_RT_FULL
extern int __cond_resched_softirq(void);
#define cond_resched_softirq() ({ \
__might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
__cond_resched_softirq(); \
})
+#else
+# define cond_resched_softirq() cond_resched()
+#endif
static inline void cond_resched_rcu(void)
{
@@ -2669,6 +2834,26 @@
#endif /* CONFIG_SMP */
+static inline int __migrate_disabled(struct task_struct *p)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ return p->migrate_disable;
+#else
+ return 0;
+#endif
+}
+
+/* Future-safe accessor for struct task_struct's cpus_allowed. */
+static inline const struct cpumask *tsk_cpus_allowed(struct task_struct *p)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (p->migrate_disable)
+ return cpumask_of(task_cpu(p));
+#endif
+
+ return &p->cpus_allowed;
+}
+
extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
diff --git a/include/linux/sched/rt.h b/include/linux/sched/rt.h
index 440434d..4d54d6c 100644
--- a/include/linux/sched/rt.h
+++ b/include/linux/sched/rt.h
@@ -35,6 +35,7 @@
#ifdef CONFIG_RT_MUTEXES
extern int rt_mutex_getprio(struct task_struct *p);
extern void rt_mutex_setprio(struct task_struct *p, int prio);
+extern int rt_mutex_check_prio(struct task_struct *task, int newprio);
extern void rt_mutex_adjust_pi(struct task_struct *p);
static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
{
@@ -45,6 +46,10 @@
{
return p->normal_prio;
}
+static inline int rt_mutex_check_prio(struct task_struct *task, int newprio)
+{
+ return 0;
+}
# define rt_mutex_adjust_pi(p) do { } while (0)
static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
{
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index 21a2093..019a936 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -152,18 +152,30 @@
* Sequence counter only version assumes that callers are using their
* own mutexing.
*/
-static inline void write_seqcount_begin(seqcount_t *s)
+static inline void __write_seqcount_begin(seqcount_t *s)
{
s->sequence++;
smp_wmb();
}
-static inline void write_seqcount_end(seqcount_t *s)
+static inline void write_seqcount_begin(seqcount_t *s)
+{
+ preempt_disable_rt();
+ __write_seqcount_begin(s);
+}
+
+static inline void __write_seqcount_end(seqcount_t *s)
{
smp_wmb();
s->sequence++;
}
+static inline void write_seqcount_end(seqcount_t *s)
+{
+ __write_seqcount_end(s);
+ preempt_enable_rt();
+}
+
/**
* write_seqcount_barrier - invalidate in-progress read-side seq operations
* @s: pointer to seqcount_t
@@ -204,10 +216,32 @@
/*
* Read side functions for starting and finalizing a read side section.
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
static inline unsigned read_seqbegin(const seqlock_t *sl)
{
return read_seqcount_begin(&sl->seqcount);
}
+#else
+/*
+ * Starvation safe read side for RT
+ */
+static inline unsigned read_seqbegin(seqlock_t *sl)
+{
+ unsigned ret;
+
+repeat:
+ ret = ACCESS_ONCE(sl->seqcount.sequence);
+ if (unlikely(ret & 1)) {
+ /*
+ * Take the lock and let the writer proceed (i.e. evtl
+ * boost it), otherwise we could loop here forever.
+ */
+ spin_unlock_wait(&sl->lock);
+ goto repeat;
+ }
+ return ret;
+}
+#endif
static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start)
{
@@ -222,36 +256,36 @@
static inline void write_seqlock(seqlock_t *sl)
{
spin_lock(&sl->lock);
- write_seqcount_begin(&sl->seqcount);
+ __write_seqcount_begin(&sl->seqcount);
}
static inline void write_sequnlock(seqlock_t *sl)
{
- write_seqcount_end(&sl->seqcount);
+ __write_seqcount_end(&sl->seqcount);
spin_unlock(&sl->lock);
}
static inline void write_seqlock_bh(seqlock_t *sl)
{
spin_lock_bh(&sl->lock);
- write_seqcount_begin(&sl->seqcount);
+ __write_seqcount_begin(&sl->seqcount);
}
static inline void write_sequnlock_bh(seqlock_t *sl)
{
- write_seqcount_end(&sl->seqcount);
+ __write_seqcount_end(&sl->seqcount);
spin_unlock_bh(&sl->lock);
}
static inline void write_seqlock_irq(seqlock_t *sl)
{
spin_lock_irq(&sl->lock);
- write_seqcount_begin(&sl->seqcount);
+ __write_seqcount_begin(&sl->seqcount);
}
static inline void write_sequnlock_irq(seqlock_t *sl)
{
- write_seqcount_end(&sl->seqcount);
+ __write_seqcount_end(&sl->seqcount);
spin_unlock_irq(&sl->lock);
}
@@ -260,7 +294,7 @@
unsigned long flags;
spin_lock_irqsave(&sl->lock, flags);
- write_seqcount_begin(&sl->seqcount);
+ __write_seqcount_begin(&sl->seqcount);
return flags;
}
@@ -270,7 +304,7 @@
static inline void
write_sequnlock_irqrestore(seqlock_t *sl, unsigned long flags)
{
- write_seqcount_end(&sl->seqcount);
+ __write_seqcount_end(&sl->seqcount);
spin_unlock_irqrestore(&sl->lock, flags);
}
diff --git a/include/linux/signal.h b/include/linux/signal.h
index 53944e5..bdb5313 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -226,6 +226,7 @@
}
extern void flush_sigqueue(struct sigpending *queue);
+extern void flush_task_sigqueue(struct task_struct *tsk);
/* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
static inline int valid_signal(unsigned long sig)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 6242a9f..fe737d3 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -133,6 +133,7 @@
__u32 qlen;
spinlock_t lock;
+ raw_spinlock_t raw_lock;
};
struct sk_buff;
@@ -1075,6 +1076,12 @@
__skb_queue_head_init(list);
}
+static inline void skb_queue_head_init_raw(struct sk_buff_head *list)
+{
+ raw_spin_lock_init(&list->raw_lock);
+ __skb_queue_head_init(list);
+}
+
static inline void skb_queue_head_init_class(struct sk_buff_head *list,
struct lock_class_key *class)
{
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 731f523..e05b694 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -188,6 +188,9 @@
#define get_cpu() ({ preempt_disable(); smp_processor_id(); })
#define put_cpu() preempt_enable()
+#define get_cpu_light() ({ migrate_disable(); smp_processor_id(); })
+#define put_cpu_light() migrate_enable()
+
/*
* Callback to arch code if there's nosmp or maxcpus=0 on the
* boot command line:
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 75f3494..a124f92 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -262,7 +262,11 @@
#define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock))
/* Include rwlock functions */
-#include <linux/rwlock.h>
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/rwlock_rt.h>
+#else
+# include <linux/rwlock.h>
+#endif
/*
* Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
@@ -273,6 +277,10 @@
# include <linux/spinlock_api_up.h>
#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/spinlock_rt.h>
+#else /* PREEMPT_RT_FULL */
+
/*
* Map the spin_lock functions to the raw variants for PREEMPT_RT=n
*/
@@ -402,4 +410,6 @@
#define atomic_dec_and_lock(atomic, lock) \
__cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
+#endif /* !PREEMPT_RT_FULL */
+
#endif /* __LINUX_SPINLOCK_H */
diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h
index bdb9993..1356078 100644
--- a/include/linux/spinlock_api_smp.h
+++ b/include/linux/spinlock_api_smp.h
@@ -191,6 +191,8 @@
return 0;
}
-#include <linux/rwlock_api_smp.h>
+#ifndef CONFIG_PREEMPT_RT_FULL
+# include <linux/rwlock_api_smp.h>
+#endif
#endif /* __LINUX_SPINLOCK_API_SMP_H */
diff --git a/include/linux/spinlock_rt.h b/include/linux/spinlock_rt.h
new file mode 100644
index 0000000..ac6f08b
--- /dev/null
+++ b/include/linux/spinlock_rt.h
@@ -0,0 +1,166 @@
+#ifndef __LINUX_SPINLOCK_RT_H
+#define __LINUX_SPINLOCK_RT_H
+
+#ifndef __LINUX_SPINLOCK_H
+#error Do not include directly. Use spinlock.h
+#endif
+
+#include <linux/bug.h>
+
+extern void
+__rt_spin_lock_init(spinlock_t *lock, char *name, struct lock_class_key *key);
+
+#define spin_lock_init(slock) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ rt_mutex_init(&(slock)->lock); \
+ __rt_spin_lock_init(slock, #slock, &__key); \
+} while (0)
+
+extern void __lockfunc rt_spin_lock(spinlock_t *lock);
+extern unsigned long __lockfunc rt_spin_lock_trace_flags(spinlock_t *lock);
+extern void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass);
+extern void __lockfunc rt_spin_unlock(spinlock_t *lock);
+extern void __lockfunc rt_spin_unlock_after_trylock_in_irq(spinlock_t *lock);
+extern void __lockfunc rt_spin_unlock_wait(spinlock_t *lock);
+extern int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags);
+extern int __lockfunc rt_spin_trylock_bh(spinlock_t *lock);
+extern int __lockfunc rt_spin_trylock(spinlock_t *lock);
+extern int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock);
+
+/*
+ * lockdep-less calls, for derived types like rwlock:
+ * (for trylock they can use rt_mutex_trylock() directly.
+ */
+extern void __lockfunc __rt_spin_lock(struct rt_mutex *lock);
+extern void __lockfunc __rt_spin_unlock(struct rt_mutex *lock);
+
+#define spin_lock(lock) \
+ do { \
+ migrate_disable(); \
+ rt_spin_lock(lock); \
+ } while (0)
+
+#define spin_lock_bh(lock) \
+ do { \
+ local_bh_disable(); \
+ migrate_disable(); \
+ rt_spin_lock(lock); \
+ } while (0)
+
+#define spin_lock_irq(lock) spin_lock(lock)
+
+#define spin_do_trylock(lock) __cond_lock(lock, rt_spin_trylock(lock))
+
+#define spin_trylock(lock) \
+({ \
+ int __locked; \
+ migrate_disable(); \
+ __locked = spin_do_trylock(lock); \
+ if (!__locked) \
+ migrate_enable(); \
+ __locked; \
+})
+
+#ifdef CONFIG_LOCKDEP
+# define spin_lock_nested(lock, subclass) \
+ do { \
+ migrate_disable(); \
+ rt_spin_lock_nested(lock, subclass); \
+ } while (0)
+
+# define spin_lock_irqsave_nested(lock, flags, subclass) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = 0; \
+ migrate_disable(); \
+ rt_spin_lock_nested(lock, subclass); \
+ } while (0)
+#else
+# define spin_lock_nested(lock, subclass) spin_lock(lock)
+
+# define spin_lock_irqsave_nested(lock, flags, subclass) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = 0; \
+ spin_lock(lock); \
+ } while (0)
+#endif
+
+#define spin_lock_irqsave(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ flags = 0; \
+ spin_lock(lock); \
+ } while (0)
+
+static inline unsigned long spin_lock_trace_flags(spinlock_t *lock)
+{
+ unsigned long flags = 0;
+#ifdef CONFIG_TRACE_IRQFLAGS
+ flags = rt_spin_lock_trace_flags(lock);
+#else
+ spin_lock(lock); /* lock_local */
+#endif
+ return flags;
+}
+
+/* FIXME: we need rt_spin_lock_nest_lock */
+#define spin_lock_nest_lock(lock, nest_lock) spin_lock_nested(lock, 0)
+
+#define spin_unlock(lock) \
+ do { \
+ rt_spin_unlock(lock); \
+ migrate_enable(); \
+ } while (0)
+
+#define spin_unlock_bh(lock) \
+ do { \
+ rt_spin_unlock(lock); \
+ migrate_enable(); \
+ local_bh_enable(); \
+ } while (0)
+
+#define spin_unlock_irq(lock) spin_unlock(lock)
+
+#define spin_unlock_irqrestore(lock, flags) \
+ do { \
+ typecheck(unsigned long, flags); \
+ (void) flags; \
+ spin_unlock(lock); \
+ } while (0)
+
+#define spin_trylock_bh(lock) __cond_lock(lock, rt_spin_trylock_bh(lock))
+#define spin_trylock_irq(lock) spin_trylock(lock)
+
+#define spin_trylock_irqsave(lock, flags) \
+ rt_spin_trylock_irqsave(lock, &(flags))
+
+#define spin_unlock_wait(lock) rt_spin_unlock_wait(lock)
+
+#ifdef CONFIG_GENERIC_LOCKBREAK
+# define spin_is_contended(lock) ((lock)->break_lock)
+#else
+# define spin_is_contended(lock) (((void)(lock), 0))
+#endif
+
+static inline int spin_can_lock(spinlock_t *lock)
+{
+ return !rt_mutex_is_locked(&lock->lock);
+}
+
+static inline int spin_is_locked(spinlock_t *lock)
+{
+ return rt_mutex_is_locked(&lock->lock);
+}
+
+static inline void assert_spin_locked(spinlock_t *lock)
+{
+ BUG_ON(!spin_is_locked(lock));
+}
+
+#define atomic_dec_and_lock(atomic, lock) \
+ atomic_dec_and_spin_lock(atomic, lock)
+
+#endif
diff --git a/include/linux/spinlock_types.h b/include/linux/spinlock_types.h
index 73548eb..10bac71 100644
--- a/include/linux/spinlock_types.h
+++ b/include/linux/spinlock_types.h
@@ -9,80 +9,15 @@
* Released under the General Public License (GPL).
*/
-#if defined(CONFIG_SMP)
-# include <asm/spinlock_types.h>
+#include <linux/spinlock_types_raw.h>
+
+#ifndef CONFIG_PREEMPT_RT_FULL
+# include <linux/spinlock_types_nort.h>
+# include <linux/rwlock_types.h>
#else
-# include <linux/spinlock_types_up.h>
+# include <linux/rtmutex.h>
+# include <linux/spinlock_types_rt.h>
+# include <linux/rwlock_types_rt.h>
#endif
-#include <linux/lockdep.h>
-
-typedef struct raw_spinlock {
- arch_spinlock_t raw_lock;
-#ifdef CONFIG_GENERIC_LOCKBREAK
- unsigned int break_lock;
-#endif
-#ifdef CONFIG_DEBUG_SPINLOCK
- unsigned int magic, owner_cpu;
- void *owner;
-#endif
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
- struct lockdep_map dep_map;
-#endif
-} raw_spinlock_t;
-
-#define SPINLOCK_MAGIC 0xdead4ead
-
-#define SPINLOCK_OWNER_INIT ((void *)-1L)
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define SPIN_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname }
-#else
-# define SPIN_DEP_MAP_INIT(lockname)
-#endif
-
-#ifdef CONFIG_DEBUG_SPINLOCK
-# define SPIN_DEBUG_INIT(lockname) \
- .magic = SPINLOCK_MAGIC, \
- .owner_cpu = -1, \
- .owner = SPINLOCK_OWNER_INIT,
-#else
-# define SPIN_DEBUG_INIT(lockname)
-#endif
-
-#define __RAW_SPIN_LOCK_INITIALIZER(lockname) \
- { \
- .raw_lock = __ARCH_SPIN_LOCK_UNLOCKED, \
- SPIN_DEBUG_INIT(lockname) \
- SPIN_DEP_MAP_INIT(lockname) }
-
-#define __RAW_SPIN_LOCK_UNLOCKED(lockname) \
- (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
-
-#define DEFINE_RAW_SPINLOCK(x) raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x)
-
-typedef struct spinlock {
- union {
- struct raw_spinlock rlock;
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define LOCK_PADSIZE (offsetof(struct raw_spinlock, dep_map))
- struct {
- u8 __padding[LOCK_PADSIZE];
- struct lockdep_map dep_map;
- };
-#endif
- };
-} spinlock_t;
-
-#define __SPIN_LOCK_INITIALIZER(lockname) \
- { { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } }
-
-#define __SPIN_LOCK_UNLOCKED(lockname) \
- (spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname)
-
-#define DEFINE_SPINLOCK(x) spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
-
-#include <linux/rwlock_types.h>
-
#endif /* __LINUX_SPINLOCK_TYPES_H */
diff --git a/include/linux/spinlock_types_nort.h b/include/linux/spinlock_types_nort.h
new file mode 100644
index 0000000..f1dac1f
--- /dev/null
+++ b/include/linux/spinlock_types_nort.h
@@ -0,0 +1,33 @@
+#ifndef __LINUX_SPINLOCK_TYPES_NORT_H
+#define __LINUX_SPINLOCK_TYPES_NORT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+/*
+ * The non RT version maps spinlocks to raw_spinlocks
+ */
+typedef struct spinlock {
+ union {
+ struct raw_spinlock rlock;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define LOCK_PADSIZE (offsetof(struct raw_spinlock, dep_map))
+ struct {
+ u8 __padding[LOCK_PADSIZE];
+ struct lockdep_map dep_map;
+ };
+#endif
+ };
+} spinlock_t;
+
+#define __SPIN_LOCK_INITIALIZER(lockname) \
+ { { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } }
+
+#define __SPIN_LOCK_UNLOCKED(lockname) \
+ (spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname)
+
+#define DEFINE_SPINLOCK(x) spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
+
+#endif
diff --git a/include/linux/spinlock_types_raw.h b/include/linux/spinlock_types_raw.h
new file mode 100644
index 0000000..edffc4d
--- /dev/null
+++ b/include/linux/spinlock_types_raw.h
@@ -0,0 +1,56 @@
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
+#define __LINUX_SPINLOCK_TYPES_RAW_H
+
+#if defined(CONFIG_SMP)
+# include <asm/spinlock_types.h>
+#else
+# include <linux/spinlock_types_up.h>
+#endif
+
+#include <linux/lockdep.h>
+
+typedef struct raw_spinlock {
+ arch_spinlock_t raw_lock;
+#ifdef CONFIG_GENERIC_LOCKBREAK
+ unsigned int break_lock;
+#endif
+#ifdef CONFIG_DEBUG_SPINLOCK
+ unsigned int magic, owner_cpu;
+ void *owner;
+#endif
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+} raw_spinlock_t;
+
+#define SPINLOCK_MAGIC 0xdead4ead
+
+#define SPINLOCK_OWNER_INIT ((void *)-1L)
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define SPIN_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname }
+#else
+# define SPIN_DEP_MAP_INIT(lockname)
+#endif
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+# define SPIN_DEBUG_INIT(lockname) \
+ .magic = SPINLOCK_MAGIC, \
+ .owner_cpu = -1, \
+ .owner = SPINLOCK_OWNER_INIT,
+#else
+# define SPIN_DEBUG_INIT(lockname)
+#endif
+
+#define __RAW_SPIN_LOCK_INITIALIZER(lockname) \
+ { \
+ .raw_lock = __ARCH_SPIN_LOCK_UNLOCKED, \
+ SPIN_DEBUG_INIT(lockname) \
+ SPIN_DEP_MAP_INIT(lockname) }
+
+#define __RAW_SPIN_LOCK_UNLOCKED(lockname) \
+ (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
+
+#define DEFINE_RAW_SPINLOCK(x) raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x)
+
+#endif
diff --git a/include/linux/spinlock_types_rt.h b/include/linux/spinlock_types_rt.h
new file mode 100644
index 0000000..9fd4319
--- /dev/null
+++ b/include/linux/spinlock_types_rt.h
@@ -0,0 +1,51 @@
+#ifndef __LINUX_SPINLOCK_TYPES_RT_H
+#define __LINUX_SPINLOCK_TYPES_RT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+#include <linux/cache.h>
+
+/*
+ * PREEMPT_RT: spinlocks - an RT mutex plus lock-break field:
+ */
+typedef struct spinlock {
+ struct rt_mutex lock;
+ unsigned int break_lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+} spinlock_t;
+
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+# define __RT_SPIN_INITIALIZER(name) \
+ { \
+ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
+ .save_state = 1, \
+ .file = __FILE__, \
+ .line = __LINE__ , \
+ }
+#else
+# define __RT_SPIN_INITIALIZER(name) \
+ { \
+ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
+ .save_state = 1, \
+ }
+#endif
+
+/*
+.wait_list = PLIST_HEAD_INIT_RAW((name).lock.wait_list, (name).lock.wait_lock)
+*/
+
+#define __SPIN_LOCK_UNLOCKED(name) \
+ { .lock = __RT_SPIN_INITIALIZER(name.lock), \
+ SPIN_DEP_MAP_INIT(name) }
+
+#define __DEFINE_SPINLOCK(name) \
+ spinlock_t name = __SPIN_LOCK_UNLOCKED(name)
+
+#define DEFINE_SPINLOCK(name) \
+ spinlock_t name __cacheline_aligned_in_smp = __SPIN_LOCK_UNLOCKED(name)
+
+#endif
diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index c114614..d5e50dd 100644
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -84,10 +84,10 @@
void process_srcu(struct work_struct *work);
-#define __SRCU_STRUCT_INIT(name) \
+#define __SRCU_STRUCT_INIT(name, pcpu_name) \
{ \
.completed = -300, \
- .per_cpu_ref = &name##_srcu_array, \
+ .per_cpu_ref = &pcpu_name, \
.queue_lock = __SPIN_LOCK_UNLOCKED(name.queue_lock), \
.running = false, \
.batch_queue = RCU_BATCH_INIT(name.batch_queue), \
@@ -104,11 +104,12 @@
*/
#define DEFINE_SRCU(name) \
static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
- struct srcu_struct name = __SRCU_STRUCT_INIT(name);
+ struct srcu_struct name = __SRCU_STRUCT_INIT(name, name##_srcu_array);
#define DEFINE_STATIC_SRCU(name) \
static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
- static struct srcu_struct name = __SRCU_STRUCT_INIT(name);
+ static struct srcu_struct name = __SRCU_STRUCT_INIT(\
+ name, name##_srcu_array);
/**
* call_srcu() - Queue a callback for invocation after an SRCU grace period
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 14a8ff2..b15655f 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -25,6 +25,7 @@
#include <linux/rcupdate.h>
#include <linux/wait.h>
#include <linux/rbtree.h>
+#include <linux/atomic.h>
#include <uapi/linux/sysctl.h>
/* For the /proc/sys support */
diff --git a/include/linux/timer.h b/include/linux/timer.h
index 8c5a197..5fcd72c 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -241,7 +241,7 @@
extern int try_to_del_timer_sync(struct timer_list *timer);
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
extern int del_timer_sync(struct timer_list *timer);
#else
# define del_timer_sync(t) del_timer(t)
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 5ca0951..44b3751 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -6,37 +6,36 @@
/*
* These routines enable/disable the pagefault handler in that
- * it will not take any locks and go straight to the fixup table.
- *
- * They have great resemblance to the preempt_disable/enable calls
- * and in fact they are identical; this is because currently there is
- * no other way to make the pagefault handlers do this. So we do
- * disable preemption but we don't necessarily care about that.
+ * it will not take any MM locks and go straight to the fixup table.
*/
-static inline void pagefault_disable(void)
+static inline void raw_pagefault_disable(void)
{
inc_preempt_count();
- /*
- * make sure to have issued the store before a pagefault
- * can hit.
- */
barrier();
}
+static inline void raw_pagefault_enable(void)
+{
+ barrier();
+ dec_preempt_count();
+ barrier();
+ preempt_check_resched();
+}
+
+#ifndef CONFIG_PREEMPT_RT_FULL
+static inline void pagefault_disable(void)
+{
+ raw_pagefault_disable();
+}
+
static inline void pagefault_enable(void)
{
- /*
- * make sure to issue those last loads/stores before enabling
- * the pagefault handler again.
- */
- barrier();
- dec_preempt_count();
- /*
- * make sure we do..
- */
- barrier();
- preempt_check_resched();
+ raw_pagefault_enable();
}
+#else
+extern void pagefault_disable(void);
+extern void pagefault_enable(void);
+#endif
#ifndef ARCH_HAS_NOCACHE_UACCESS
@@ -77,9 +76,9 @@
mm_segment_t old_fs = get_fs(); \
\
set_fs(KERNEL_DS); \
- pagefault_disable(); \
+ raw_pagefault_disable(); \
ret = __copy_from_user_inatomic(&(retval), (__force typeof(retval) __user *)(addr), sizeof(retval)); \
- pagefault_enable(); \
+ raw_pagefault_enable(); \
set_fs(old_fs); \
ret; \
})
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 06f28be..d115f62 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -26,6 +26,7 @@
#include <linux/errno.h>
#include <linux/rbtree.h>
+#include <linux/wait.h>
struct vm_area_struct;
struct mm_struct;
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 67ce70c..fe37043 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -29,7 +29,9 @@
static inline void __count_vm_event(enum vm_event_item item)
{
+ preempt_disable_rt();
__this_cpu_inc(vm_event_states.event[item]);
+ preempt_enable_rt();
}
static inline void count_vm_event(enum vm_event_item item)
@@ -39,7 +41,9 @@
static inline void __count_vm_events(enum vm_event_item item, long delta)
{
+ preempt_disable_rt();
__this_cpu_add(vm_event_states.event[item], delta);
+ preempt_enable_rt();
}
static inline void count_vm_events(enum vm_event_item item, long delta)
diff --git a/include/linux/wait-simple.h b/include/linux/wait-simple.h
new file mode 100644
index 0000000..f86bca2
--- /dev/null
+++ b/include/linux/wait-simple.h
@@ -0,0 +1,207 @@
+#ifndef _LINUX_WAIT_SIMPLE_H
+#define _LINUX_WAIT_SIMPLE_H
+
+#include <linux/spinlock.h>
+#include <linux/list.h>
+
+#include <asm/current.h>
+
+struct swaiter {
+ struct task_struct *task;
+ struct list_head node;
+};
+
+#define DEFINE_SWAITER(name) \
+ struct swaiter name = { \
+ .task = current, \
+ .node = LIST_HEAD_INIT((name).node), \
+ }
+
+struct swait_head {
+ raw_spinlock_t lock;
+ struct list_head list;
+};
+
+#define SWAIT_HEAD_INITIALIZER(name) { \
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock), \
+ .list = LIST_HEAD_INIT((name).list), \
+ }
+
+#define DEFINE_SWAIT_HEAD(name) \
+ struct swait_head name = SWAIT_HEAD_INITIALIZER(name)
+
+extern void __init_swait_head(struct swait_head *h, struct lock_class_key *key);
+
+#define init_swait_head(swh) \
+ do { \
+ static struct lock_class_key __key; \
+ \
+ __init_swait_head((swh), &__key); \
+ } while (0)
+
+/*
+ * Waiter functions
+ */
+extern void swait_prepare_locked(struct swait_head *head, struct swaiter *w);
+extern void swait_prepare(struct swait_head *head, struct swaiter *w, int state);
+extern void swait_finish_locked(struct swait_head *head, struct swaiter *w);
+extern void swait_finish(struct swait_head *head, struct swaiter *w);
+
+/* Check whether a head has waiters enqueued */
+static inline bool swaitqueue_active(struct swait_head *h)
+{
+ /* Make sure the condition is visible before checking list_empty() */
+ smp_mb();
+ return !list_empty(&h->list);
+}
+
+/*
+ * Wakeup functions
+ */
+extern unsigned int __swait_wake(struct swait_head *head, unsigned int state, unsigned int num);
+extern unsigned int __swait_wake_locked(struct swait_head *head, unsigned int state, unsigned int num);
+
+#define swait_wake(head) __swait_wake(head, TASK_NORMAL, 1)
+#define swait_wake_interruptible(head) __swait_wake(head, TASK_INTERRUPTIBLE, 1)
+#define swait_wake_all(head) __swait_wake(head, TASK_NORMAL, 0)
+#define swait_wake_all_interruptible(head) __swait_wake(head, TASK_INTERRUPTIBLE, 0)
+
+/*
+ * Event API
+ */
+#define __swait_event(wq, condition) \
+do { \
+ DEFINE_SWAITER(__wait); \
+ \
+ for (;;) { \
+ swait_prepare(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
+ if (condition) \
+ break; \
+ schedule(); \
+ } \
+ swait_finish(&wq, &__wait); \
+} while (0)
+
+/**
+ * swait_event - sleep until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ *
+ * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ */
+#define swait_event(wq, condition) \
+do { \
+ if (condition) \
+ break; \
+ __swait_event(wq, condition); \
+} while (0)
+
+#define __swait_event_interruptible(wq, condition, ret) \
+do { \
+ DEFINE_SWAITER(__wait); \
+ \
+ for (;;) { \
+ swait_prepare(&wq, &__wait, TASK_INTERRUPTIBLE); \
+ if (condition) \
+ break; \
+ if (signal_pending(current)) { \
+ ret = -ERESTARTSYS; \
+ break; \
+ } \
+ schedule(); \
+ } \
+ swait_finish(&wq, &__wait); \
+} while (0)
+
+#define __swait_event_interruptible_timeout(wq, condition, ret) \
+do { \
+ DEFINE_SWAITER(__wait); \
+ \
+ for (;;) { \
+ swait_prepare(&wq, &__wait, TASK_INTERRUPTIBLE); \
+ if (condition) \
+ break; \
+ if (signal_pending(current)) { \
+ ret = -ERESTARTSYS; \
+ break; \
+ } \
+ ret = schedule_timeout(ret); \
+ if (!ret) \
+ break; \
+ } \
+ swait_finish(&wq, &__wait); \
+} while (0)
+
+/**
+ * swait_event_interruptible - sleep until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ *
+ * The process is put to sleep (TASK_INTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ */
+#define swait_event_interruptible(wq, condition) \
+({ \
+ int __ret = 0; \
+ if (!(condition)) \
+ __swait_event_interruptible(wq, condition, __ret); \
+ __ret; \
+})
+
+#define swait_event_interruptible_timeout(wq, condition, timeout) \
+({ \
+ int __ret = timeout; \
+ if (!(condition)) \
+ __swait_event_interruptible_timeout(wq, condition, __ret); \
+ __ret; \
+})
+
+#define __swait_event_timeout(wq, condition, ret) \
+do { \
+ DEFINE_SWAITER(__wait); \
+ \
+ for (;;) { \
+ swait_prepare(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
+ if (condition) \
+ break; \
+ ret = schedule_timeout(ret); \
+ if (!ret) \
+ break; \
+ } \
+ swait_finish(&wq, &__wait); \
+} while (0)
+
+/**
+ * swait_event_timeout - sleep until a condition gets true or a timeout elapses
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ * @timeout: timeout, in jiffies
+ *
+ * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ *
+ * The function returns 0 if the @timeout elapsed, and the remaining
+ * jiffies if the condition evaluated to true before the timeout elapsed.
+ */
+#define swait_event_timeout(wq, condition, timeout) \
+({ \
+ long __ret = timeout; \
+ if (!(condition)) \
+ __swait_event_timeout(wq, condition, __ret); \
+ __ret; \
+})
+
+#endif
diff --git a/include/linux/wait.h b/include/linux/wait.h
index a67fc16..68f7245 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -7,6 +7,7 @@
#include <linux/spinlock.h>
#include <asm/current.h>
#include <uapi/linux/wait.h>
+#include <linux/atomic.h>
typedef struct __wait_queue wait_queue_t;
typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
diff --git a/include/linux/work-simple.h b/include/linux/work-simple.h
new file mode 100644
index 0000000..f175fa9
--- /dev/null
+++ b/include/linux/work-simple.h
@@ -0,0 +1,24 @@
+#ifndef _LINUX_SWORK_H
+#define _LINUX_SWORK_H
+
+#include <linux/list.h>
+
+struct swork_event {
+ struct list_head item;
+ unsigned long flags;
+ void (*func)(struct swork_event *);
+};
+
+static inline void INIT_SWORK(struct swork_event *event,
+ void (*func)(struct swork_event *))
+{
+ event->flags = 0;
+ event->func = func;
+}
+
+bool swork_queue(struct swork_event *sev);
+
+int swork_get(void);
+void swork_put(void);
+
+#endif /* _LINUX_SWORK_H */
diff --git a/include/net/dst.h b/include/net/dst.h
index d30afbd..fc5a8f2 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -428,7 +428,7 @@
static inline int dst_neigh_output(struct dst_entry *dst, struct neighbour *n,
struct sk_buff *skb)
{
- const struct hh_cache *hh;
+ struct hh_cache *hh;
if (dst->pending_confirm) {
unsigned long now = jiffies;
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 536501a..a9d84bfe 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -333,7 +333,7 @@
}
#endif
-static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
+static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
{
unsigned int seq;
int hh_len;
@@ -388,7 +388,7 @@
#define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb)
-static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
+static inline void neigh_ha_snapshot(char *dst, struct neighbour *n,
const struct net_device *dev)
{
unsigned int seq;
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 51f3470..2fd9cf57 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -58,6 +58,7 @@
int sysctl_icmp_echo_ignore_all;
int sysctl_icmp_echo_ignore_broadcasts;
+ int sysctl_icmp_echo_sysrq;
int sysctl_icmp_ignore_bogus_error_responses;
int sysctl_icmp_ratelimit;
int sysctl_icmp_ratemask;
diff --git a/include/trace/events/hist.h b/include/trace/events/hist.h
new file mode 100644
index 0000000..f7710de
--- /dev/null
+++ b/include/trace/events/hist.h
@@ -0,0 +1,73 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM hist
+
+#if !defined(_TRACE_HIST_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HIST_H
+
+#include "latency_hist.h"
+#include <linux/tracepoint.h>
+
+#if !defined(CONFIG_PREEMPT_OFF_HIST) && !defined(CONFIG_INTERRUPT_OFF_HIST)
+#define trace_preemptirqsoff_hist(a, b)
+#define trace_preemptirqsoff_hist_rcuidle(a, b)
+#else
+TRACE_EVENT(preemptirqsoff_hist,
+
+ TP_PROTO(int reason, int starthist),
+
+ TP_ARGS(reason, starthist),
+
+ TP_STRUCT__entry(
+ __field(int, reason)
+ __field(int, starthist)
+ ),
+
+ TP_fast_assign(
+ __entry->reason = reason;
+ __entry->starthist = starthist;
+ ),
+
+ TP_printk("reason=%s starthist=%s", getaction(__entry->reason),
+ __entry->starthist ? "start" : "stop")
+);
+#endif
+
+#ifndef CONFIG_MISSED_TIMER_OFFSETS_HIST
+#define trace_hrtimer_interrupt(a, b, c, d)
+#else
+TRACE_EVENT(hrtimer_interrupt,
+
+ TP_PROTO(int cpu, long long offset, struct task_struct *curr,
+ struct task_struct *task),
+
+ TP_ARGS(cpu, offset, curr, task),
+
+ TP_STRUCT__entry(
+ __field(int, cpu)
+ __field(long long, offset)
+ __array(char, ccomm, TASK_COMM_LEN)
+ __field(int, cprio)
+ __array(char, tcomm, TASK_COMM_LEN)
+ __field(int, tprio)
+ ),
+
+ TP_fast_assign(
+ __entry->cpu = cpu;
+ __entry->offset = offset;
+ memcpy(__entry->ccomm, curr->comm, TASK_COMM_LEN);
+ __entry->cprio = curr->prio;
+ memcpy(__entry->tcomm, task != NULL ? task->comm : "<none>",
+ task != NULL ? TASK_COMM_LEN : 7);
+ __entry->tprio = task != NULL ? task->prio : -1;
+ ),
+
+ TP_printk("cpu=%d offset=%lld curr=%s[%d] thread=%s[%d]",
+ __entry->cpu, __entry->offset, __entry->ccomm,
+ __entry->cprio, __entry->tcomm, __entry->tprio)
+);
+#endif
+
+#endif /* _TRACE_HIST_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/include/trace/events/latency_hist.h b/include/trace/events/latency_hist.h
new file mode 100644
index 0000000..d3f2fbd
--- /dev/null
+++ b/include/trace/events/latency_hist.h
@@ -0,0 +1,29 @@
+#ifndef _LATENCY_HIST_H
+#define _LATENCY_HIST_H
+
+enum hist_action {
+ IRQS_ON,
+ PREEMPT_ON,
+ TRACE_STOP,
+ IRQS_OFF,
+ PREEMPT_OFF,
+ TRACE_START,
+};
+
+static char *actions[] = {
+ "IRQS_ON",
+ "PREEMPT_ON",
+ "TRACE_STOP",
+ "IRQS_OFF",
+ "PREEMPT_OFF",
+ "TRACE_START",
+};
+
+static inline char *getaction(int action)
+{
+ if (action >= 0 && action <= sizeof(actions)/sizeof(actions[0]))
+ return actions[action];
+ return "unknown";
+}
+
+#endif /* _LATENCY_HIST_H */
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 2e7d994..004eb03 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -55,9 +55,9 @@
*/
DECLARE_EVENT_CLASS(sched_wakeup_template,
- TP_PROTO(struct task_struct *p, int success),
+ TP_PROTO(struct task_struct *p),
- TP_ARGS(__perf_task(p), success),
+ TP_ARGS(__perf_task(p)),
TP_STRUCT__entry(
__array( char, comm, TASK_COMM_LEN )
@@ -71,25 +71,37 @@
memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
__entry->pid = p->pid;
__entry->prio = p->prio;
- __entry->success = success;
+ __entry->success = 1; /* rudiment, kill when possible */
__entry->target_cpu = task_cpu(p);
),
- TP_printk("comm=%s pid=%d prio=%d success=%d target_cpu=%03d",
+ TP_printk("comm=%s pid=%d prio=%d target_cpu=%03d",
__entry->comm, __entry->pid, __entry->prio,
- __entry->success, __entry->target_cpu)
+ __entry->target_cpu)
);
+/*
+ * Tracepoint called when waking a task; this tracepoint is guaranteed to be
+ * called from the waking context.
+ */
+DEFINE_EVENT(sched_wakeup_template, sched_waking,
+ TP_PROTO(struct task_struct *p),
+ TP_ARGS(p));
+
+/*
+ * Tracepoint called when the task is actually woken; p->state == TASK_RUNNNG.
+ * It it not always called from the waking context.
+ */
DEFINE_EVENT(sched_wakeup_template, sched_wakeup,
- TP_PROTO(struct task_struct *p, int success),
- TP_ARGS(p, success));
+ TP_PROTO(struct task_struct *p),
+ TP_ARGS(p));
/*
* Tracepoint for waking up a new task:
*/
DEFINE_EVENT(sched_wakeup_template, sched_wakeup_new,
- TP_PROTO(struct task_struct *p, int success),
- TP_ARGS(p, success));
+ TP_PROTO(struct task_struct *p),
+ TP_ARGS(p));
#ifdef CREATE_TRACE_POINTS
static inline long __trace_sched_switch_state(struct task_struct *p)
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 645d749..1c74dcd 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -536,6 +536,9 @@
\
local_save_flags(irq_flags); \
pc = preempt_count(); \
+ /* Account for tracepoint preempt disable */ \
+ if (IS_ENABLED(CONFIG_PREEMPT)) \
+ pc--; \
\
__data_size = ftrace_get_offsets_##call(&__data_offsets, args); \
\
diff --git a/init/Kconfig b/init/Kconfig
index 734aa01..836b34e 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -615,7 +615,7 @@
config RCU_FAST_NO_HZ
bool "Accelerate last non-dyntick-idle CPU's grace periods"
- depends on NO_HZ_COMMON && SMP
+ depends on NO_HZ_COMMON && SMP && !PREEMPT_RT_FULL
default n
help
This option permits CPUs to enter dynticks-idle state even if
@@ -642,7 +642,7 @@
config RCU_BOOST
bool "Enable RCU priority boosting"
depends on RT_MUTEXES && PREEMPT_RCU
- default n
+ default y if PREEMPT_RT_FULL
help
This option boosts the priority of preempted RCU readers that
block the current preemptible RCU grace period for too long.
@@ -1042,6 +1042,7 @@
config RT_GROUP_SCHED
bool "Group scheduling for SCHED_RR/FIFO"
depends on CGROUP_SCHED
+ depends on !PREEMPT_RT_FULL
default n
help
This feature lets you explicitly allocate real CPU bandwidth
@@ -1583,6 +1584,7 @@
config SLAB
bool "SLAB"
+ depends on !PREEMPT_RT_FULL
help
The regular slab allocator that is established and known to work
well in all environments. It organizes cache hot objects in
@@ -1601,6 +1603,7 @@
config SLOB
depends on EXPERT
bool "SLOB (Simple Allocator)"
+ depends on !PREEMPT_RT_FULL
help
SLOB replaces the stock allocator with a drastically simpler
allocator. SLOB is generally more space efficient but
diff --git a/init/Makefile b/init/Makefile
index 7bc47ee..88cf473 100644
--- a/init/Makefile
+++ b/init/Makefile
@@ -33,4 +33,4 @@
include/generated/compile.h: FORCE
@$($(quiet)chk_compile.h)
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@ \
- "$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CC) $(KBUILD_CFLAGS)"
+ "$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CONFIG_PREEMPT_RT_FULL)" "$(CC) $(KBUILD_CFLAGS)"
diff --git a/init/main.c b/init/main.c
index 1812218..0db119a 100644
--- a/init/main.c
+++ b/init/main.c
@@ -6,7 +6,7 @@
* GK 2/5/95 - Changed to support mounting root fs via NFS
* Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
* Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
- * Simplified starting of init: Michael A. Griffith <grif@acm.org>
+ * Simplified starting of init: Michael A. Griffith <grif@acm.org>
*/
#define DEBUG /* Enable initcall_debug */
@@ -74,6 +74,7 @@
#include <linux/ptrace.h>
#include <linux/blkdev.h>
#include <linux/elevator.h>
+#include <linux/posix-timers.h>
#include <linux/sched_clock.h>
#include <linux/context_tracking.h>
#include <linux/random.h>
@@ -507,6 +508,7 @@
setup_command_line(command_line);
setup_nr_cpu_ids();
setup_per_cpu_areas();
+ softirq_early_init();
smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
build_all_zonelists(NULL, NULL);
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 82bb5e8..3498cba 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -920,12 +920,17 @@
struct msg_msg *message,
struct ext_wait_queue *receiver)
{
+ /*
+ * Keep them in one critical section for PREEMPT_RT:
+ */
+ preempt_disable_rt();
receiver->msg = message;
list_del(&receiver->list);
receiver->state = STATE_PENDING;
wake_up_process(receiver->task);
smp_wmb();
receiver->state = STATE_READY;
+ preempt_enable_rt();
}
/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
@@ -939,13 +944,18 @@
wake_up_interruptible(&info->wait_q);
return;
}
- if (msg_insert(sender->msg, info))
- return;
- list_del(&sender->list);
- sender->state = STATE_PENDING;
- wake_up_process(sender->task);
- smp_wmb();
- sender->state = STATE_READY;
+ /*
+ * Keep them in one critical section for PREEMPT_RT:
+ */
+ preempt_disable_rt();
+ if (!msg_insert(sender->msg, info)) {
+ list_del(&sender->list);
+ sender->state = STATE_PENDING;
+ wake_up_process(sender->task);
+ smp_wmb();
+ sender->state = STATE_READY;
+ }
+ preempt_enable_rt();
}
SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
diff --git a/ipc/msg.c b/ipc/msg.c
index b92acb6..11e60452 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -253,10 +253,18 @@
struct msg_receiver *msr, *t;
list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
+ /*
+ * Make sure that the wakeup doesnt preempt
+ * this CPU prematurely. (on PREEMPT_RT)
+ */
+ preempt_disable_rt();
+
msr->r_msg = NULL;
wake_up_process(msr->r_tsk);
smp_mb();
msr->r_msg = ERR_PTR(res);
+
+ preempt_enable_rt();
}
}
@@ -636,6 +644,12 @@
!security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
msr->r_msgtype, msr->r_mode)) {
+ /*
+ * Make sure that the wakeup doesnt preempt
+ * this CPU prematurely. (on PREEMPT_RT)
+ */
+ preempt_disable_rt();
+
list_del(&msr->r_list);
if (msr->r_maxsize < msg->m_ts) {
msr->r_msg = NULL;
@@ -649,9 +663,11 @@
wake_up_process(msr->r_tsk);
smp_mb();
msr->r_msg = msg;
+ preempt_enable_rt();
return 1;
}
+ preempt_enable_rt();
}
}
return 0;
diff --git a/ipc/sem.c b/ipc/sem.c
index 857f7f8..9b6ead1 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -702,6 +702,13 @@
static void wake_up_sem_queue_prepare(struct list_head *pt,
struct sem_queue *q, int error)
{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ struct task_struct *p = q->sleeper;
+ get_task_struct(p);
+ q->status = error;
+ wake_up_process(p);
+ put_task_struct(p);
+#else
if (list_empty(pt)) {
/*
* Hold preempt off so that we don't get preempted and have the
@@ -713,6 +720,7 @@
q->pid = error;
list_add_tail(&q->list, pt);
+#endif
}
/**
@@ -726,6 +734,7 @@
*/
static void wake_up_sem_queue_do(struct list_head *pt)
{
+#ifndef CONFIG_PREEMPT_RT_BASE
struct sem_queue *q, *t;
int did_something;
@@ -738,6 +747,7 @@
}
if (did_something)
preempt_enable();
+#endif
}
static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks
index ecee67a..b867a1c 100644
--- a/kernel/Kconfig.locks
+++ b/kernel/Kconfig.locks
@@ -225,4 +225,4 @@
config MUTEX_SPIN_ON_OWNER
def_bool y
- depends on SMP && !DEBUG_MUTEXES && ARCH_SUPPORTS_ATOMIC_RMW
+ depends on SMP && !DEBUG_MUTEXES && ARCH_SUPPORTS_ATOMIC_RMW && !PREEMPT_RT_FULL
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index 3f9c974..11dbe26 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -1,3 +1,16 @@
+config PREEMPT
+ bool
+ select PREEMPT_COUNT
+
+config PREEMPT_RT_BASE
+ bool
+ select PREEMPT
+
+config HAVE_PREEMPT_LAZY
+ bool
+
+config PREEMPT_LAZY
+ def_bool y if HAVE_PREEMPT_LAZY && PREEMPT_RT_FULL
choice
prompt "Preemption Model"
@@ -33,9 +46,9 @@
Select this if you are building a kernel for a desktop system.
-config PREEMPT
+config PREEMPT__LL
bool "Preemptible Kernel (Low-Latency Desktop)"
- select PREEMPT_COUNT
+ select PREEMPT
select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK
help
This option reduces the latency of the kernel by making
@@ -52,6 +65,22 @@
embedded system with latency requirements in the milliseconds
range.
+config PREEMPT_RTB
+ bool "Preemptible Kernel (Basic RT)"
+ select PREEMPT_RT_BASE
+ help
+ This option is basically the same as (Low-Latency Desktop) but
+ enables changes which are preliminary for the full preemptible
+ RT kernel.
+
+config PREEMPT_RT_FULL
+ bool "Fully Preemptible Kernel (RT)"
+ depends on IRQ_FORCED_THREADING
+ select PREEMPT_RT_BASE
+ select PREEMPT_RCU
+ help
+ All and everything
+
endchoice
config PREEMPT_COUNT
diff --git a/kernel/Makefile b/kernel/Makefile
index 1ce4755..b3ff0a8 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -7,10 +7,10 @@
sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \
signal.o sys.o kmod.o workqueue.o pid.o task_work.o \
rcupdate.o extable.o params.o posix-timers.o \
- kthread.o wait.o sys_ni.o posix-cpu-timers.o mutex.o \
- hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
+ kthread.o wait.o sys_ni.o posix-cpu-timers.o \
+ hrtimer.o nsproxy.o srcu.o semaphore.o \
notifier.o ksysfs.o cred.o reboot.o \
- async.o range.o groups.o lglock.o smpboot.o
+ async.o range.o groups.o lglock.o smpboot.o wait-simple.o
ifdef CONFIG_FUNCTION_TRACER
# Do not trace debug files and internal ftrace files
@@ -33,7 +33,11 @@
obj-$(CONFIG_PROFILING) += profile.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-y += time/
+ifneq ($(CONFIG_PREEMPT_RT_FULL),y)
+obj-y += mutex.o
obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
+obj-y += rwsem.o
+endif
obj-$(CONFIG_LOCKDEP) += lockdep.o
ifeq ($(CONFIG_PROC_FS),y)
obj-$(CONFIG_LOCKDEP) += lockdep_proc.o
@@ -45,6 +49,7 @@
obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
+obj-$(CONFIG_PREEMPT_RT_FULL) += rt.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
obj-$(CONFIG_SMP) += smp.o
ifneq ($(CONFIG_SMP),y)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index c1f258a..c7ecc9d 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -63,6 +63,290 @@
.refcount = 0,
};
+/**
+ * hotplug_pcp - per cpu hotplug descriptor
+ * @unplug: set when pin_current_cpu() needs to sync tasks
+ * @sync_tsk: the task that waits for tasks to finish pinned sections
+ * @refcount: counter of tasks in pinned sections
+ * @grab_lock: set when the tasks entering pinned sections should wait
+ * @synced: notifier for @sync_tsk to tell cpu_down it's finished
+ * @mutex: the mutex to make tasks wait (used when @grab_lock is true)
+ * @mutex_init: zero if the mutex hasn't been initialized yet.
+ *
+ * Although @unplug and @sync_tsk may point to the same task, the @unplug
+ * is used as a flag and still exists after @sync_tsk has exited and
+ * @sync_tsk set to NULL.
+ */
+struct hotplug_pcp {
+ struct task_struct *unplug;
+ struct task_struct *sync_tsk;
+ int refcount;
+ int grab_lock;
+ struct completion synced;
+ struct completion unplug_wait;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /*
+ * Note, on PREEMPT_RT, the hotplug lock must save the state of
+ * the task, otherwise the mutex will cause the task to fail
+ * to sleep when required. (Because it's called from migrate_disable())
+ *
+ * The spinlock_t on PREEMPT_RT is a mutex that saves the task's
+ * state.
+ */
+ spinlock_t lock;
+#else
+ struct mutex mutex;
+#endif
+ int mutex_init;
+};
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define hotplug_lock(hp) rt_spin_lock(&(hp)->lock)
+# define hotplug_unlock(hp) rt_spin_unlock(&(hp)->lock)
+#else
+# define hotplug_lock(hp) mutex_lock(&(hp)->mutex)
+# define hotplug_unlock(hp) mutex_unlock(&(hp)->mutex)
+#endif
+
+static DEFINE_PER_CPU(struct hotplug_pcp, hotplug_pcp);
+
+/**
+ * pin_current_cpu - Prevent the current cpu from being unplugged
+ *
+ * Lightweight version of get_online_cpus() to prevent cpu from being
+ * unplugged when code runs in a migration disabled region.
+ *
+ * Must be called with preemption disabled (preempt_count = 1)!
+ */
+void pin_current_cpu(void)
+{
+ struct hotplug_pcp *hp;
+ int force = 0;
+
+retry:
+ hp = &__get_cpu_var(hotplug_pcp);
+
+ if (!hp->unplug || hp->refcount || force || preempt_count() > 1 ||
+ hp->unplug == current) {
+ hp->refcount++;
+ return;
+ }
+ if (hp->grab_lock) {
+ preempt_enable();
+ hotplug_lock(hp);
+ hotplug_unlock(hp);
+ } else {
+ preempt_enable();
+ /*
+ * Try to push this task off of this CPU.
+ */
+ if (!migrate_me()) {
+ preempt_disable();
+ hp = &__get_cpu_var(hotplug_pcp);
+ if (!hp->grab_lock) {
+ /*
+ * Just let it continue it's already pinned
+ * or about to sleep.
+ */
+ force = 1;
+ goto retry;
+ }
+ preempt_enable();
+ }
+ }
+ preempt_disable();
+ goto retry;
+}
+
+/**
+ * unpin_current_cpu - Allow unplug of current cpu
+ *
+ * Must be called with preemption or interrupts disabled!
+ */
+void unpin_current_cpu(void)
+{
+ struct hotplug_pcp *hp = &__get_cpu_var(hotplug_pcp);
+
+ WARN_ON(hp->refcount <= 0);
+
+ /* This is safe. sync_unplug_thread is pinned to this cpu */
+ if (!--hp->refcount && hp->unplug && hp->unplug != current)
+ wake_up_process(hp->unplug);
+}
+
+static void wait_for_pinned_cpus(struct hotplug_pcp *hp)
+{
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ while (hp->refcount) {
+ schedule_preempt_disabled();
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ }
+}
+
+static int sync_unplug_thread(void *data)
+{
+ struct hotplug_pcp *hp = data;
+
+ wait_for_completion(&hp->unplug_wait);
+ preempt_disable();
+ hp->unplug = current;
+ wait_for_pinned_cpus(hp);
+
+ /*
+ * This thread will synchronize the cpu_down() with threads
+ * that have pinned the CPU. When the pinned CPU count reaches
+ * zero, we inform the cpu_down code to continue to the next step.
+ */
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ preempt_enable();
+ complete(&hp->synced);
+
+ /*
+ * If all succeeds, the next step will need tasks to wait till
+ * the CPU is offline before continuing. To do this, the grab_lock
+ * is set and tasks going into pin_current_cpu() will block on the
+ * mutex. But we still need to wait for those that are already in
+ * pinned CPU sections. If the cpu_down() failed, the kthread_should_stop()
+ * will kick this thread out.
+ */
+ while (!hp->grab_lock && !kthread_should_stop()) {
+ schedule();
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ }
+
+ /* Make sure grab_lock is seen before we see a stale completion */
+ smp_mb();
+
+ /*
+ * Now just before cpu_down() enters stop machine, we need to make
+ * sure all tasks that are in pinned CPU sections are out, and new
+ * tasks will now grab the lock, keeping them from entering pinned
+ * CPU sections.
+ */
+ if (!kthread_should_stop()) {
+ preempt_disable();
+ wait_for_pinned_cpus(hp);
+ preempt_enable();
+ complete(&hp->synced);
+ }
+
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ while (!kthread_should_stop()) {
+ schedule();
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ }
+ set_current_state(TASK_RUNNING);
+
+ /*
+ * Force this thread off this CPU as it's going down and
+ * we don't want any more work on this CPU.
+ */
+ current->flags &= ~PF_NO_SETAFFINITY;
+ set_cpus_allowed_ptr(current, cpu_present_mask);
+ migrate_me();
+ return 0;
+}
+
+static void __cpu_unplug_sync(struct hotplug_pcp *hp)
+{
+ wake_up_process(hp->sync_tsk);
+ wait_for_completion(&hp->synced);
+}
+
+static void __cpu_unplug_wait(unsigned int cpu)
+{
+ struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+
+ complete(&hp->unplug_wait);
+ wait_for_completion(&hp->synced);
+}
+
+/*
+ * Start the sync_unplug_thread on the target cpu and wait for it to
+ * complete.
+ */
+static int cpu_unplug_begin(unsigned int cpu)
+{
+ struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+ int err;
+
+ /* Protected by cpu_hotplug.lock */
+ if (!hp->mutex_init) {
+#ifdef CONFIG_PREEMPT_RT_FULL
+ spin_lock_init(&hp->lock);
+#else
+ mutex_init(&hp->mutex);
+#endif
+ hp->mutex_init = 1;
+ }
+
+ /* Inform the scheduler to migrate tasks off this CPU */
+ tell_sched_cpu_down_begin(cpu);
+
+ init_completion(&hp->synced);
+ init_completion(&hp->unplug_wait);
+
+ hp->sync_tsk = kthread_create(sync_unplug_thread, hp, "sync_unplug/%d", cpu);
+ if (IS_ERR(hp->sync_tsk)) {
+ err = PTR_ERR(hp->sync_tsk);
+ hp->sync_tsk = NULL;
+ return err;
+ }
+ kthread_bind(hp->sync_tsk, cpu);
+
+ /*
+ * Wait for tasks to get out of the pinned sections,
+ * it's still OK if new tasks enter. Some CPU notifiers will
+ * wait for tasks that are going to enter these sections and
+ * we must not have them block.
+ */
+ wake_up_process(hp->sync_tsk);
+ return 0;
+}
+
+static void cpu_unplug_sync(unsigned int cpu)
+{
+ struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+
+ init_completion(&hp->synced);
+ /* The completion needs to be initialzied before setting grab_lock */
+ smp_wmb();
+
+ /* Grab the mutex before setting grab_lock */
+ hotplug_lock(hp);
+ hp->grab_lock = 1;
+
+ /*
+ * The CPU notifiers have been completed.
+ * Wait for tasks to get out of pinned CPU sections and have new
+ * tasks block until the CPU is completely down.
+ */
+ __cpu_unplug_sync(hp);
+
+ /* All done with the sync thread */
+ kthread_stop(hp->sync_tsk);
+ hp->sync_tsk = NULL;
+}
+
+static void cpu_unplug_done(unsigned int cpu)
+{
+ struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+
+ hp->unplug = NULL;
+ /* Let all tasks know cpu unplug is finished before cleaning up */
+ smp_wmb();
+
+ if (hp->sync_tsk)
+ kthread_stop(hp->sync_tsk);
+
+ if (hp->grab_lock) {
+ hotplug_unlock(hp);
+ /* protected by cpu_hotplug.lock */
+ hp->grab_lock = 0;
+ }
+ tell_sched_cpu_down_done(cpu);
+}
+
void get_online_cpus(void)
{
might_sleep();
@@ -79,15 +363,14 @@
{
if (cpu_hotplug.active_writer == current)
return;
- mutex_lock(&cpu_hotplug.lock);
+ mutex_lock(&cpu_hotplug.lock);
if (WARN_ON(!cpu_hotplug.refcount))
cpu_hotplug.refcount++; /* try to fix things up */
if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer))
wake_up_process(cpu_hotplug.active_writer);
mutex_unlock(&cpu_hotplug.lock);
-
}
EXPORT_SYMBOL_GPL(put_online_cpus);
@@ -281,13 +564,15 @@
/* Requires cpu_add_remove_lock to be held */
static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
{
- int err, nr_calls = 0;
+ int mycpu, err, nr_calls = 0;
void *hcpu = (void *)(long)cpu;
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct take_cpu_down_param tcd_param = {
.mod = mod,
.hcpu = hcpu,
};
+ cpumask_var_t cpumask;
+ cpumask_var_t cpumask_org;
if (num_online_cpus() == 1)
return -EBUSY;
@@ -295,7 +580,34 @@
if (!cpu_online(cpu))
return -EINVAL;
+ /* Move the downtaker off the unplug cpu */
+ if (!alloc_cpumask_var(&cpumask, GFP_KERNEL))
+ return -ENOMEM;
+ if (!alloc_cpumask_var(&cpumask_org, GFP_KERNEL)) {
+ free_cpumask_var(cpumask);
+ return -ENOMEM;
+ }
+
+ cpumask_copy(cpumask_org, tsk_cpus_allowed(current));
+ cpumask_andnot(cpumask, cpu_online_mask, cpumask_of(cpu));
+ set_cpus_allowed_ptr(current, cpumask);
+ free_cpumask_var(cpumask);
+ migrate_disable();
+ mycpu = smp_processor_id();
+ if (mycpu == cpu) {
+ printk(KERN_ERR "Yuck! Still on unplug CPU\n!");
+ migrate_enable();
+ err = -EBUSY;
+ goto restore_cpus;
+ }
+ migrate_enable();
+
cpu_hotplug_begin();
+ err = cpu_unplug_begin(cpu);
+ if (err) {
+ printk("cpu_unplug_begin(%d) failed\n", cpu);
+ goto out_cancel;
+ }
err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
if (err) {
@@ -305,8 +617,13 @@
__func__, cpu);
goto out_release;
}
+
+ __cpu_unplug_wait(cpu);
smpboot_park_threads(cpu);
+ /* Notifiers are done. Don't let any more tasks pin this CPU. */
+ cpu_unplug_sync(cpu);
+
err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
if (err) {
/* CPU didn't die: tell everyone. Can't complain. */
@@ -335,9 +652,14 @@
check_for_tasks(cpu);
out_release:
+ cpu_unplug_done(cpu);
+out_cancel:
cpu_hotplug_done();
if (!err)
cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
+restore_cpus:
+ set_cpus_allowed_ptr(current, cpumask_org);
+ free_cpumask_var(cpumask_org);
return err;
}
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 14ff484..399dba6 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -554,7 +554,6 @@
int linecount;
int colcount;
int logging, saved_loglevel = 0;
- int saved_trap_printk;
int got_printf_lock = 0;
int retlen = 0;
int fnd, len;
@@ -565,8 +564,6 @@
unsigned long uninitialized_var(flags);
preempt_disable();
- saved_trap_printk = kdb_trap_printk;
- kdb_trap_printk = 0;
/* Serialize kdb_printf if multiple cpus try to write at once.
* But if any cpu goes recursive in kdb, just print the output,
@@ -833,7 +830,6 @@
} else {
__release(kdb_printf_lock);
}
- kdb_trap_printk = saved_trap_printk;
preempt_enable();
return retlen;
}
@@ -843,9 +839,11 @@
va_list ap;
int r;
+ kdb_trap_printk++;
va_start(ap, fmt);
r = vkdb_printf(fmt, ap);
va_end(ap);
+ kdb_trap_printk--;
return r;
}
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 0a360d3..48b5113 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6099,6 +6099,7 @@
hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hwc->hrtimer.function = perf_swevent_hrtimer;
+ hwc->hrtimer.irqsafe = 1;
/*
* Since hrtimers have a fixed rate, we can do a static freq->period
diff --git a/kernel/exit.c b/kernel/exit.c
index 81b3d67..3b93e6a 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -146,7 +146,7 @@
* Do this under ->siglock, we can race with another thread
* doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
*/
- flush_sigqueue(&tsk->pending);
+ flush_task_sigqueue(tsk);
tsk->sighand = NULL;
spin_unlock(&sighand->siglock);
diff --git a/kernel/fork.c b/kernel/fork.c
index 00e6407..8405379 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -96,7 +96,7 @@
DEFINE_PER_CPU(unsigned long, process_counts) = 0;
-__cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */
+DEFINE_RWLOCK(tasklist_lock); /* outer */
#ifdef CONFIG_PROVE_RCU
int lockdep_tasklist_lock_is_held(void)
@@ -232,7 +232,9 @@
if (atomic_dec_and_test(&sig->sigcnt))
free_signal_struct(sig);
}
-
+#ifdef CONFIG_PREEMPT_RT_BASE
+static
+#endif
void __put_task_struct(struct task_struct *tsk)
{
WARN_ON(!tsk->exit_state);
@@ -247,7 +249,18 @@
if (!profile_handoff_task(tsk))
free_task(tsk);
}
+#ifndef CONFIG_PREEMPT_RT_BASE
EXPORT_SYMBOL_GPL(__put_task_struct);
+#else
+void __put_task_struct_cb(struct rcu_head *rhp)
+{
+ struct task_struct *tsk = container_of(rhp, struct task_struct, put_rcu);
+
+ __put_task_struct(tsk);
+
+}
+EXPORT_SYMBOL_GPL(__put_task_struct_cb);
+#endif
void __init __weak arch_task_cache_init(void) { }
@@ -601,6 +614,19 @@
}
EXPORT_SYMBOL_GPL(__mmdrop);
+#ifdef CONFIG_PREEMPT_RT_BASE
+/*
+ * RCU callback for delayed mm drop. Not strictly rcu, but we don't
+ * want another facility to make this work.
+ */
+void __mmdrop_delayed(struct rcu_head *rhp)
+{
+ struct mm_struct *mm = container_of(rhp, struct mm_struct, delayed_drop);
+
+ __mmdrop(mm);
+}
+#endif
+
/*
* Decrement the use count and release all resources for an mm.
*/
@@ -1116,6 +1142,9 @@
*/
static void posix_cpu_timers_init(struct task_struct *tsk)
{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ tsk->posix_timer_list = NULL;
+#endif
tsk->cputime_expires.prof_exp = 0;
tsk->cputime_expires.virt_exp = 0;
tsk->cputime_expires.sched_exp = 0;
@@ -1245,6 +1274,7 @@
spin_lock_init(&p->alloc_lock);
init_sigpending(&p->pending);
+ p->sigqueue_cache = NULL;
p->utime = p->stime = p->gtime = 0;
p->utimescaled = p->stimescaled = 0;
@@ -1252,7 +1282,8 @@
p->prev_cputime.utime = p->prev_cputime.stime = 0;
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
- seqlock_init(&p->vtime_seqlock);
+ raw_spin_lock_init(&p->vtime_lock);
+ seqcount_init(&p->vtime_seq);
p->vtime_snap = 0;
p->vtime_snap_whence = VTIME_SLEEPING;
#endif
@@ -1305,6 +1336,9 @@
p->hardirq_context = 0;
p->softirq_context = 0;
#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+ p->pagefault_disabled = 0;
+#endif
#ifdef CONFIG_LOCKDEP
p->lockdep_depth = 0; /* no locks held yet */
p->curr_chain_key = 0;
@@ -1677,7 +1711,7 @@
#ifdef __ARCH_WANT_SYS_VFORK
SYSCALL_DEFINE0(vfork)
{
- return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0,
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0,
0, NULL, NULL);
}
#endif
diff --git a/kernel/futex.c b/kernel/futex.c
index 566e2e0..2dfcbca 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -581,7 +581,9 @@
* task still owns the PI-state:
*/
if (head->next != next) {
+ raw_spin_unlock_irq(&curr->pi_lock);
spin_unlock(&hb->lock);
+ raw_spin_lock_irq(&curr->pi_lock);
continue;
}
@@ -649,97 +651,91 @@
* [10] There is no transient state which leaves owner and user space
* TID out of sync.
*/
-static int
-lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
- union futex_key *key, struct futex_pi_state **ps)
+
+/*
+ * Validate that the existing waiter has a pi_state and sanity check
+ * the pi_state against the user space value. If correct, attach to
+ * it.
+ */
+static int attach_to_pi_state(u32 uval, struct futex_pi_state *pi_state,
+ struct futex_pi_state **ps)
{
- struct futex_pi_state *pi_state = NULL;
- struct futex_q *this, *next;
- struct plist_head *head;
- struct task_struct *p;
pid_t pid = uval & FUTEX_TID_MASK;
- head = &hb->chain;
+ /*
+ * Userspace might have messed up non-PI and PI futexes [3]
+ */
+ if (unlikely(!pi_state))
+ return -EINVAL;
- plist_for_each_entry_safe(this, next, head, list) {
- if (match_futex(&this->key, key)) {
+ WARN_ON(!atomic_read(&pi_state->refcount));
+
+ /*
+ * Handle the owner died case:
+ */
+ if (uval & FUTEX_OWNER_DIED) {
+ /*
+ * exit_pi_state_list sets owner to NULL and wakes the
+ * topmost waiter. The task which acquires the
+ * pi_state->rt_mutex will fixup owner.
+ */
+ if (!pi_state->owner) {
/*
- * Sanity check the waiter before increasing
- * the refcount and attaching to it.
+ * No pi state owner, but the user space TID
+ * is not 0. Inconsistent state. [5]
*/
- pi_state = this->pi_state;
- /*
- * Userspace might have messed up non-PI and
- * PI futexes [3]
- */
- if (unlikely(!pi_state))
+ if (pid)
return -EINVAL;
-
- WARN_ON(!atomic_read(&pi_state->refcount));
-
/*
- * Handle the owner died case:
+ * Take a ref on the state and return success. [4]
*/
- if (uval & FUTEX_OWNER_DIED) {
- /*
- * exit_pi_state_list sets owner to NULL and
- * wakes the topmost waiter. The task which
- * acquires the pi_state->rt_mutex will fixup
- * owner.
- */
- if (!pi_state->owner) {
- /*
- * No pi state owner, but the user
- * space TID is not 0. Inconsistent
- * state. [5]
- */
- if (pid)
- return -EINVAL;
- /*
- * Take a ref on the state and
- * return. [4]
- */
- goto out_state;
- }
-
- /*
- * If TID is 0, then either the dying owner
- * has not yet executed exit_pi_state_list()
- * or some waiter acquired the rtmutex in the
- * pi state, but did not yet fixup the TID in
- * user space.
- *
- * Take a ref on the state and return. [6]
- */
- if (!pid)
- goto out_state;
- } else {
- /*
- * If the owner died bit is not set,
- * then the pi_state must have an
- * owner. [7]
- */
- if (!pi_state->owner)
- return -EINVAL;
- }
-
- /*
- * Bail out if user space manipulated the
- * futex value. If pi state exists then the
- * owner TID must be the same as the user
- * space TID. [9/10]
- */
- if (pid != task_pid_vnr(pi_state->owner))
- return -EINVAL;
-
- out_state:
- atomic_inc(&pi_state->refcount);
- *ps = pi_state;
- return 0;
+ goto out_state;
}
+
+ /*
+ * If TID is 0, then either the dying owner has not
+ * yet executed exit_pi_state_list() or some waiter
+ * acquired the rtmutex in the pi state, but did not
+ * yet fixup the TID in user space.
+ *
+ * Take a ref on the state and return success. [6]
+ */
+ if (!pid)
+ goto out_state;
+ } else {
+ /*
+ * If the owner died bit is not set, then the pi_state
+ * must have an owner. [7]
+ */
+ if (!pi_state->owner)
+ return -EINVAL;
}
/*
+ * Bail out if user space manipulated the futex value. If pi
+ * state exists then the owner TID must be the same as the
+ * user space TID. [9/10]
+ */
+ if (pid != task_pid_vnr(pi_state->owner))
+ return -EINVAL;
+out_state:
+ atomic_inc(&pi_state->refcount);
+ *ps = pi_state;
+ return 0;
+}
+
+/*
+ * Lookup the task for the TID provided from user space and attach to
+ * it after doing proper sanity checks.
+ */
+static int attach_to_pi_owner(u32 uval, union futex_key *key,
+ struct futex_pi_state **ps)
+{
+ pid_t pid = uval & FUTEX_TID_MASK;
+ struct futex_pi_state *pi_state;
+ struct task_struct *p;
+
+ /*
* We are the first waiter - try to look up the real owner and attach
* the new pi_state to it, but bail out when TID = 0 [1]
*/
@@ -780,7 +776,7 @@
pi_state = alloc_pi_state();
/*
- * Initialize the pi_mutex in locked state and make 'p'
+ * Initialize the pi_mutex in locked state and make @p
* the owner of it:
*/
rt_mutex_init_proxy_locked(&pi_state->pi_mutex, p);
@@ -800,6 +796,36 @@
return 0;
}
+static int lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
+ union futex_key *key, struct futex_pi_state **ps)
+{
+ struct futex_q *match = futex_top_waiter(hb, key);
+
+ /*
+ * If there is a waiter on that futex, validate it and
+ * attach to the pi_state when the validation succeeds.
+ */
+ if (match)
+ return attach_to_pi_state(uval, match->pi_state, ps);
+
+ /*
+ * We are the first waiter - try to look up the owner based on
+ * @uval and attach to it.
+ */
+ return attach_to_pi_owner(uval, key, ps);
+}
+
+static int lock_pi_update_atomic(u32 __user *uaddr, u32 uval, u32 newval)
+{
+ u32 uninitialized_var(curval);
+
+ if (unlikely(cmpxchg_futex_value_locked(&curval, uaddr, uval, newval)))
+ return -EFAULT;
+
+ /*If user space value changed, let the caller retry */
+ return curval != uval ? -EAGAIN : 0;
+}
+
/**
* futex_lock_pi_atomic() - Atomic work required to acquire a pi aware futex
* @uaddr: the pi futex user address
@@ -823,113 +849,69 @@
struct futex_pi_state **ps,
struct task_struct *task, int set_waiters)
{
- int lock_taken, ret, force_take = 0;
- u32 uval, newval, curval, vpid = task_pid_vnr(task);
-
-retry:
- ret = lock_taken = 0;
+ u32 uval, newval, vpid = task_pid_vnr(task);
+ struct futex_q *match;
+ int ret;
/*
- * To avoid races, we attempt to take the lock here again
- * (by doing a 0 -> TID atomic cmpxchg), while holding all
- * the locks. It will most likely not succeed.
+ * Read the user space value first so we can validate a few
+ * things before proceeding further.
*/
- newval = vpid;
- if (set_waiters)
- newval |= FUTEX_WAITERS;
-
- if (unlikely(cmpxchg_futex_value_locked(&curval, uaddr, 0, newval)))
+ if (get_futex_value_locked(&uval, uaddr))
return -EFAULT;
/*
* Detect deadlocks.
*/
- if ((unlikely((curval & FUTEX_TID_MASK) == vpid)))
+ if ((unlikely((uval & FUTEX_TID_MASK) == vpid)))
return -EDEADLK;
/*
- * Surprise - we got the lock, but we do not trust user space at all.
+ * Lookup existing state first. If it exists, try to attach to
+ * its pi_state.
*/
- if (unlikely(!curval)) {
+ match = futex_top_waiter(hb, key);
+ if (match)
+ return attach_to_pi_state(uval, match->pi_state, ps);
+
+ /*
+ * No waiter and user TID is 0. We are here because the
+ * waiters or the owner died bit is set or called from
+ * requeue_cmp_pi or for whatever reason something took the
+ * syscall.
+ */
+ if (!(uval & FUTEX_TID_MASK)) {
/*
- * We verify whether there is kernel state for this
- * futex. If not, we can safely assume, that the 0 ->
- * TID transition is correct. If state exists, we do
- * not bother to fixup the user space state as it was
- * corrupted already.
+ * We take over the futex. No other waiters and the user space
+ * TID is 0. We preserve the owner died bit.
*/
- return futex_top_waiter(hb, key) ? -EINVAL : 1;
+ newval = uval & FUTEX_OWNER_DIED;
+ newval |= vpid;
+
+ /* The futex requeue_pi code can enforce the waiters bit */
+ if (set_waiters)
+ newval |= FUTEX_WAITERS;
+
+ ret = lock_pi_update_atomic(uaddr, uval, newval);
+ /* If the take over worked, return 1 */
+ return ret < 0 ? ret : 1;
}
- uval = curval;
-
/*
- * Set the FUTEX_WAITERS flag, so the owner will know it has someone
- * to wake at the next unlock.
+ * First waiter. Set the waiters bit before attaching ourself to
+ * the owner. If owner tries to unlock, it will be forced into
+ * the kernel and blocked on hb->lock.
*/
- newval = curval | FUTEX_WAITERS;
-
+ newval = uval | FUTEX_WAITERS;
+ ret = lock_pi_update_atomic(uaddr, uval, newval);
+ if (ret)
+ return ret;
/*
- * Should we force take the futex? See below.
+ * If the update of the user space value succeeded, we try to
+ * attach to the owner. If that fails, no harm done, we only
+ * set the FUTEX_WAITERS bit in the user space variable.
*/
- if (unlikely(force_take)) {
- /*
- * Keep the OWNER_DIED and the WAITERS bit and set the
- * new TID value.
- */
- newval = (curval & ~FUTEX_TID_MASK) | vpid;
- force_take = 0;
- lock_taken = 1;
- }
-
- if (unlikely(cmpxchg_futex_value_locked(&curval, uaddr, uval, newval)))
- return -EFAULT;
- if (unlikely(curval != uval))
- goto retry;
-
- /*
- * We took the lock due to forced take over.
- */
- if (unlikely(lock_taken))
- return 1;
-
- /*
- * We dont have the lock. Look up the PI state (or create it if
- * we are the first waiter):
- */
- ret = lookup_pi_state(uval, hb, key, ps);
-
- if (unlikely(ret)) {
- switch (ret) {
- case -ESRCH:
- /*
- * We failed to find an owner for this
- * futex. So we have no pi_state to block
- * on. This can happen in two cases:
- *
- * 1) The owner died
- * 2) A stale FUTEX_WAITERS bit
- *
- * Re-read the futex value.
- */
- if (get_futex_value_locked(&curval, uaddr))
- return -EFAULT;
-
- /*
- * If the owner died or we have a stale
- * WAITERS bit the owner TID in the user space
- * futex is 0.
- */
- if (!(curval & FUTEX_TID_MASK)) {
- force_take = 1;
- goto retry;
- }
- default:
- break;
- }
- }
-
- return ret;
+ return attach_to_pi_owner(uval, key, ps);
}
/**
@@ -1045,22 +1027,6 @@
return 0;
}
-static int unlock_futex_pi(u32 __user *uaddr, u32 uval)
-{
- u32 uninitialized_var(oldval);
-
- /*
- * There is no waiter, so we unlock the futex. The owner died
- * bit has not to be preserved here. We are the owner:
- */
- if (cmpxchg_futex_value_locked(&oldval, uaddr, uval, 0))
- return -EFAULT;
- if (oldval != uval)
- return -EAGAIN;
-
- return 0;
-}
-
/*
* Express the locking dependencies for lockdep:
*/
@@ -1508,7 +1474,12 @@
goto retry;
goto out;
case -EAGAIN:
- /* The owner was exiting, try again. */
+ /*
+ * Two reasons for this:
+ * - Owner is exiting and we just wait for the
+ * exit to complete.
+ * - The user space value changed.
+ */
free_pi_state(pi_state);
pi_state = NULL;
double_unlock_hb(hb1, hb2);
@@ -1569,12 +1540,22 @@
this->pi_state = pi_state;
ret = rt_mutex_start_proxy_lock(&pi_state->pi_mutex,
this->rt_waiter,
- this->task, 1);
+ this->task);
if (ret == 1) {
/* We got the lock. */
requeue_pi_wake_futex(this, &key2, hb2);
drop_count++;
continue;
+ } else if (ret == -EAGAIN) {
+ /*
+ * Waiter was woken by timeout or
+ * signal and has set pi_blocked_on to
+ * PI_WAKEUP_INPROGRESS before we
+ * tried to enqueue it on the rtmutex.
+ */
+ this->pi_state = NULL;
+ free_pi_state(pi_state);
+ continue;
} else if (ret) {
/* -EDEADLK */
this->pi_state = NULL;
@@ -2153,8 +2134,10 @@
goto uaddr_faulted;
case -EAGAIN:
/*
- * Task is exiting and we just wait for the
- * exit to complete.
+ * Two reasons for this:
+ * - Task is exiting and we just wait for the
+ * exit to complete.
+ * - The user space value changed.
*/
queue_unlock(&q, hb);
put_futex_key(&q.key);
@@ -2174,9 +2157,9 @@
/*
* Block on the PI mutex:
*/
- if (!trylock)
- ret = rt_mutex_timed_lock(&q.pi_state->pi_mutex, to, 1);
- else {
+ if (!trylock) {
+ ret = rt_mutex_timed_futex_lock(&q.pi_state->pi_mutex, to);
+ } else {
ret = rt_mutex_trylock(&q.pi_state->pi_mutex);
/* Fixup the trylock return value: */
ret = ret ? 0 : -EWOULDBLOCK;
@@ -2238,11 +2221,10 @@
*/
static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
{
- struct futex_hash_bucket *hb;
- struct futex_q *this, *next;
- struct plist_head *head;
+ u32 uninitialized_var(curval), uval, vpid = task_pid_vnr(current);
union futex_key key = FUTEX_KEY_INIT;
- u32 uval, vpid = task_pid_vnr(current);
+ struct futex_hash_bucket *hb;
+ struct futex_q *match;
int ret;
retry:
@@ -2255,61 +2237,50 @@
return -EPERM;
ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &key, VERIFY_WRITE);
- if (unlikely(ret != 0))
- goto out;
+ if (ret)
+ return ret;
hb = hash_futex(&key);
spin_lock(&hb->lock);
/*
- * To avoid races, try to do the TID -> 0 atomic transition
- * again. If it succeeds then we can return without waking
- * anyone else up. We only try this if neither the waiters nor
- * the owner died bit are set.
+ * Check waiters first. We do not trust user space values at
+ * all and we at least want to know if user space fiddled
+ * with the futex value instead of blindly unlocking.
*/
- if (!(uval & ~FUTEX_TID_MASK) &&
- cmpxchg_futex_value_locked(&uval, uaddr, vpid, 0))
- goto pi_faulted;
- /*
- * Rare case: we managed to release the lock atomically,
- * no need to wake anyone else up:
- */
- if (unlikely(uval == vpid))
- goto out_unlock;
-
- /*
- * Ok, other tasks may need to be woken up - check waiters
- * and do the wakeup if necessary:
- */
- head = &hb->chain;
-
- plist_for_each_entry_safe(this, next, head, list) {
- if (!match_futex (&this->key, &key))
- continue;
- ret = wake_futex_pi(uaddr, uval, this);
+ match = futex_top_waiter(hb, &key);
+ if (match) {
+ ret = wake_futex_pi(uaddr, uval, match);
/*
- * The atomic access to the futex value
- * generated a pagefault, so retry the
- * user-access and the wakeup:
+ * The atomic access to the futex value generated a
+ * pagefault, so retry the user-access and the wakeup:
*/
if (ret == -EFAULT)
goto pi_faulted;
goto out_unlock;
}
+
/*
- * No waiters - kernel unlocks the futex:
+ * We have no kernel internal state, i.e. no waiters in the
+ * kernel. Waiters which are about to queue themselves are stuck
+ * on hb->lock. So we can safely ignore them. We do neither
+ * preserve the WAITERS bit not the OWNER_DIED one. We are the
+ * owner.
*/
- ret = unlock_futex_pi(uaddr, uval);
- if (ret == -EFAULT)
+ if (cmpxchg_futex_value_locked(&curval, uaddr, uval, 0))
goto pi_faulted;
+ /*
+ * If uval has changed, let user space handle it.
+ */
+ ret = (curval == uval) ? 0 : -EAGAIN;
+
out_unlock:
spin_unlock(&hb->lock);
put_futex_key(&key);
-
-out:
return ret;
+
pi_faulted:
spin_unlock(&hb->lock);
put_futex_key(&key);
@@ -2415,7 +2386,7 @@
{
struct hrtimer_sleeper timeout, *to = NULL;
struct rt_mutex_waiter rt_waiter;
- struct futex_hash_bucket *hb;
+ struct futex_hash_bucket *hb, *hb2;
union futex_key key2 = FUTEX_KEY_INIT;
struct futex_q q = futex_q_init;
int res, ret;
@@ -2440,8 +2411,7 @@
* The waiter is allocated on our stack, manipulated by the requeue
* code while we sleep on uaddr.
*/
- debug_rt_mutex_init_waiter(&rt_waiter);
- rt_waiter.task = NULL;
+ rt_mutex_init_waiter(&rt_waiter, false);
ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, VERIFY_WRITE);
if (unlikely(ret != 0))
@@ -2472,20 +2442,55 @@
/* Queue the futex_q, drop the hb lock, wait for wakeup. */
futex_wait_queue_me(hb, &q, to);
- spin_lock(&hb->lock);
- ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to);
- spin_unlock(&hb->lock);
- if (ret)
- goto out_put_keys;
+ /*
+ * On RT we must avoid races with requeue and trying to block
+ * on two mutexes (hb->lock and uaddr2's rtmutex) by
+ * serializing access to pi_blocked_on with pi_lock.
+ */
+ raw_spin_lock_irq(¤t->pi_lock);
+ if (current->pi_blocked_on) {
+ /*
+ * We have been requeued or are in the process of
+ * being requeued.
+ */
+ raw_spin_unlock_irq(¤t->pi_lock);
+ } else {
+ /*
+ * Setting pi_blocked_on to PI_WAKEUP_INPROGRESS
+ * prevents a concurrent requeue from moving us to the
+ * uaddr2 rtmutex. After that we can safely acquire
+ * (and possibly block on) hb->lock.
+ */
+ current->pi_blocked_on = PI_WAKEUP_INPROGRESS;
+ raw_spin_unlock_irq(¤t->pi_lock);
+
+ spin_lock(&hb->lock);
+
+ /*
+ * Clean up pi_blocked_on. We might leak it otherwise
+ * when we succeeded with the hb->lock in the fast
+ * path.
+ */
+ raw_spin_lock_irq(¤t->pi_lock);
+ current->pi_blocked_on = NULL;
+ raw_spin_unlock_irq(¤t->pi_lock);
+
+ ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to);
+ spin_unlock(&hb->lock);
+ if (ret)
+ goto out_put_keys;
+ }
/*
- * In order for us to be here, we know our q.key == key2, and since
- * we took the hb->lock above, we also know that futex_requeue() has
- * completed and we no longer have to concern ourselves with a wakeup
- * race with the atomic proxy lock acquisition by the requeue code. The
- * futex_requeue dropped our key1 reference and incremented our key2
- * reference count.
+ * In order to be here, we have either been requeued, are in
+ * the process of being requeued, or requeue successfully
+ * acquired uaddr2 on our behalf. If pi_blocked_on was
+ * non-null above, we may be racing with a requeue. Do not
+ * rely on q->lock_ptr to be hb2->lock until after blocking on
+ * hb->lock or hb2->lock. The futex_requeue dropped our key1
+ * reference and incremented our key2 reference count.
*/
+ hb2 = hash_futex(&key2);
/* Check if the requeue code acquired the second futex for us. */
if (!q.rt_waiter) {
@@ -2494,7 +2499,8 @@
* did a lock-steal - fix up the PI-state in that case.
*/
if (q.pi_state && (q.pi_state->owner != current)) {
- spin_lock(q.lock_ptr);
+ spin_lock(&hb2->lock);
+ BUG_ON(&hb2->lock != q.lock_ptr);
ret = fixup_pi_state_owner(uaddr2, &q, current);
if (ret && rt_mutex_owner(&q.pi_state->pi_mutex) == current)
rt_mutex_unlock(&q.pi_state->pi_mutex);
@@ -2503,7 +2509,7 @@
* the requeue_pi() code acquired for us.
*/
free_pi_state(q.pi_state);
- spin_unlock(q.lock_ptr);
+ spin_unlock(&hb2->lock);
}
} else {
struct rt_mutex *pi_mutex;
@@ -2515,10 +2521,11 @@
*/
WARN_ON(!q.pi_state);
pi_mutex = &q.pi_state->pi_mutex;
- ret = rt_mutex_finish_proxy_lock(pi_mutex, to, &rt_waiter, 1);
+ ret = rt_mutex_finish_proxy_lock(pi_mutex, to, &rt_waiter);
debug_rt_mutex_free_waiter(&rt_waiter);
- spin_lock(q.lock_ptr);
+ spin_lock(&hb2->lock);
+ BUG_ON(&hb2->lock != q.lock_ptr);
/*
* Fixup the pi_state owner and possibly acquire the lock if we
* haven't already.
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 6390321..4f012ae 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -47,11 +47,13 @@
#include <linux/sched/sysctl.h>
#include <linux/sched/rt.h>
#include <linux/timer.h>
+#include <linux/kthread.h>
#include <linux/freezer.h>
#include <asm/uaccess.h>
#include <trace/events/timer.h>
+#include <trace/events/hist.h>
/*
* The timer bases:
@@ -630,8 +632,7 @@
* When the callback is running, we do not reprogram the clock event
* device. The timer callback is either running on a different CPU or
* the callback is executed in the hrtimer_interrupt context. The
- * reprogramming is handled either by the softirq, which called the
- * callback or at the end of the hrtimer_interrupt.
+ * reprogramming is handled at the end of the hrtimer_interrupt.
*/
if (hrtimer_callback_running(timer))
return 0;
@@ -666,6 +667,9 @@
return res;
}
+static void __run_hrtimer(struct hrtimer *timer, ktime_t *now);
+static int hrtimer_rt_defer(struct hrtimer *timer);
+
/*
* Initialize the high resolution related parts of cpu_base
*/
@@ -682,9 +686,18 @@
* and expiry check is done in the hrtimer_interrupt or in the softirq.
*/
static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
- struct hrtimer_clock_base *base)
+ struct hrtimer_clock_base *base,
+ int wakeup)
{
- return base->cpu_base->hres_active && hrtimer_reprogram(timer, base);
+ if (!(base->cpu_base->hres_active && hrtimer_reprogram(timer, base)))
+ return 0;
+ if (!wakeup)
+ return -ETIME;
+#ifdef CONFIG_PREEMPT_RT_BASE
+ if (!hrtimer_rt_defer(timer))
+ return -ETIME;
+#endif
+ return 1;
}
static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
@@ -752,6 +765,44 @@
static DECLARE_WORK(hrtimer_work, clock_was_set_work);
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * RT can not call schedule_work from real interrupt context.
+ * Need to make a thread to do the real work.
+ */
+static struct task_struct *clock_set_delay_thread;
+static bool do_clock_set_delay;
+
+static int run_clock_set_delay(void *ignore)
+{
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (do_clock_set_delay) {
+ do_clock_set_delay = false;
+ schedule_work(&hrtimer_work);
+ }
+ schedule();
+ }
+ __set_current_state(TASK_RUNNING);
+ return 0;
+}
+
+void clock_was_set_delayed(void)
+{
+ do_clock_set_delay = true;
+ /* Make visible before waking up process */
+ smp_wmb();
+ wake_up_process(clock_set_delay_thread);
+}
+
+static __init int create_clock_set_delay_thread(void)
+{
+ clock_set_delay_thread = kthread_run(run_clock_set_delay, NULL, "kclksetdelayd");
+ BUG_ON(!clock_set_delay_thread);
+ return 0;
+}
+early_initcall(create_clock_set_delay_thread);
+#else /* PREEMPT_RT_FULL */
/*
* Called from timekeeping and resume code to reprogramm the hrtimer
* interrupt device on all cpus.
@@ -760,6 +811,7 @@
{
schedule_work(&hrtimer_work);
}
+#endif
#else
@@ -769,12 +821,18 @@
static inline void
hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
- struct hrtimer_clock_base *base)
+ struct hrtimer_clock_base *base,
+ int wakeup)
{
return 0;
}
static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
static inline void retrigger_next_event(void *arg) { }
+static inline int hrtimer_reprogram(struct hrtimer *timer,
+ struct hrtimer_clock_base *base)
+{
+ return 0;
+}
#endif /* CONFIG_HIGH_RES_TIMERS */
@@ -893,6 +951,32 @@
}
EXPORT_SYMBOL_GPL(hrtimer_forward);
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define wake_up_timer_waiters(b) wake_up(&(b)->wait)
+
+/**
+ * hrtimer_wait_for_timer - Wait for a running timer
+ *
+ * @timer: timer to wait for
+ *
+ * The function waits in case the timers callback function is
+ * currently executed on the waitqueue of the timer base. The
+ * waitqueue is woken up after the timer callback function has
+ * finished execution.
+ */
+void hrtimer_wait_for_timer(const struct hrtimer *timer)
+{
+ struct hrtimer_clock_base *base = timer->base;
+
+ if (base && base->cpu_base && !timer->irqsafe)
+ wait_event(base->cpu_base->wait,
+ !(timer->state & HRTIMER_STATE_CALLBACK));
+}
+
+#else
+# define wake_up_timer_waiters(b) do { } while (0)
+#endif
+
/*
* enqueue_hrtimer - internal function to (re)start a timer
*
@@ -936,6 +1020,11 @@
if (!(timer->state & HRTIMER_STATE_ENQUEUED))
goto out;
+ if (unlikely(!list_empty(&timer->cb_entry))) {
+ list_del_init(&timer->cb_entry);
+ goto out;
+ }
+
next_timer = timerqueue_getnext(&base->active);
timerqueue_del(&base->active, &timer->node);
if (&timer->node == next_timer) {
@@ -1022,6 +1111,17 @@
/* Switch the timer base, if necessary: */
new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ {
+ ktime_t now = new_base->get_time();
+
+ if (ktime_to_ns(tim) < ktime_to_ns(now))
+ timer->praecox = now;
+ else
+ timer->praecox = ktime_set(0, 0);
+ }
+#endif
+
timer_stats_hrtimer_set_start_info(timer);
leftmost = enqueue_hrtimer(timer, new_base);
@@ -1032,9 +1132,19 @@
*
* XXX send_remote_softirq() ?
*/
- if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases)
- && hrtimer_enqueue_reprogram(timer, new_base)) {
- if (wakeup) {
+ if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases)) {
+ ret = hrtimer_enqueue_reprogram(timer, new_base, wakeup);
+ if (ret < 0) {
+ /*
+ * In case we failed to reprogram the timer (mostly
+ * because out current timer is already elapsed),
+ * remove it again and report a failure. This avoids
+ * stale base->first entries.
+ */
+ debug_deactivate(timer);
+ __remove_hrtimer(timer, new_base,
+ timer->state & HRTIMER_STATE_CALLBACK, 0);
+ } else if (ret > 0) {
/*
* We need to drop cpu_base->lock to avoid a
* lock ordering issue vs. rq->lock.
@@ -1042,9 +1152,7 @@
raw_spin_unlock(&new_base->cpu_base->lock);
raise_softirq_irqoff(HRTIMER_SOFTIRQ);
local_irq_restore(flags);
- return ret;
- } else {
- __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+ return 0;
}
}
@@ -1134,7 +1242,7 @@
if (ret >= 0)
return ret;
- cpu_relax();
+ hrtimer_wait_for_timer(timer);
}
}
EXPORT_SYMBOL_GPL(hrtimer_cancel);
@@ -1213,6 +1321,7 @@
base = hrtimer_clockid_to_base(clock_id);
timer->base = &cpu_base->clock_base[base];
+ INIT_LIST_HEAD(&timer->cb_entry);
timerqueue_init(&timer->node);
#ifdef CONFIG_TIMER_STATS
@@ -1296,6 +1405,126 @@
timer->state &= ~HRTIMER_STATE_CALLBACK;
}
+static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer);
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+static void hrtimer_rt_reprogram(int restart, struct hrtimer *timer,
+ struct hrtimer_clock_base *base)
+{
+ /*
+ * Note, we clear the callback flag before we requeue the
+ * timer otherwise we trigger the callback_running() check
+ * in hrtimer_reprogram().
+ */
+ timer->state &= ~HRTIMER_STATE_CALLBACK;
+
+ if (restart != HRTIMER_NORESTART) {
+ BUG_ON(hrtimer_active(timer));
+ /*
+ * Enqueue the timer, if it's the leftmost timer then
+ * we need to reprogram it.
+ */
+ if (!enqueue_hrtimer(timer, base))
+ return;
+
+#ifndef CONFIG_HIGH_RES_TIMERS
+ }
+#else
+ if (base->cpu_base->hres_active &&
+ hrtimer_reprogram(timer, base))
+ goto requeue;
+
+ } else if (hrtimer_active(timer)) {
+ /*
+ * If the timer was rearmed on another CPU, reprogram
+ * the event device.
+ */
+ if (&timer->node == base->active.next &&
+ base->cpu_base->hres_active &&
+ hrtimer_reprogram(timer, base))
+ goto requeue;
+ }
+ return;
+
+requeue:
+ /*
+ * Timer is expired. Thus move it from tree to pending list
+ * again.
+ */
+ __remove_hrtimer(timer, base, timer->state, 0);
+ list_add_tail(&timer->cb_entry, &base->expired);
+#endif
+}
+
+/*
+ * The changes in mainline which removed the callback modes from
+ * hrtimer are not yet working with -rt. The non wakeup_process()
+ * based callbacks which involve sleeping locks need to be treated
+ * seperately.
+ */
+static void hrtimer_rt_run_pending(void)
+{
+ enum hrtimer_restart (*fn)(struct hrtimer *);
+ struct hrtimer_cpu_base *cpu_base;
+ struct hrtimer_clock_base *base;
+ struct hrtimer *timer;
+ int index, restart;
+
+ local_irq_disable();
+ cpu_base = &per_cpu(hrtimer_bases, smp_processor_id());
+
+ raw_spin_lock(&cpu_base->lock);
+
+ for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
+ base = &cpu_base->clock_base[index];
+
+ while (!list_empty(&base->expired)) {
+ timer = list_first_entry(&base->expired,
+ struct hrtimer, cb_entry);
+
+ /*
+ * Same as the above __run_hrtimer function
+ * just we run with interrupts enabled.
+ */
+ debug_hrtimer_deactivate(timer);
+ __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
+ timer_stats_account_hrtimer(timer);
+ fn = timer->function;
+
+ raw_spin_unlock_irq(&cpu_base->lock);
+ restart = fn(timer);
+ raw_spin_lock_irq(&cpu_base->lock);
+
+ hrtimer_rt_reprogram(restart, timer, base);
+ }
+ }
+
+ raw_spin_unlock_irq(&cpu_base->lock);
+
+ wake_up_timer_waiters(cpu_base);
+}
+
+static int hrtimer_rt_defer(struct hrtimer *timer)
+{
+ if (timer->irqsafe)
+ return 0;
+
+ __remove_hrtimer(timer, timer->base, timer->state, 0);
+ list_add_tail(&timer->cb_entry, &timer->base->expired);
+ return 1;
+}
+
+#else
+
+static inline void hrtimer_rt_run_pending(void)
+{
+ hrtimer_peek_ahead_timers();
+}
+
+static inline int hrtimer_rt_defer(struct hrtimer *timer) { return 0; }
+
+#endif
+
#ifdef CONFIG_HIGH_RES_TIMERS
/*
@@ -1306,7 +1535,7 @@
{
struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
ktime_t expires_next, now, entry_time, delta;
- int i, retries = 0;
+ int i, retries = 0, raise = 0;
BUG_ON(!cpu_base->hres_active);
cpu_base->nr_events++;
@@ -1341,6 +1570,15 @@
timer = container_of(node, struct hrtimer, node);
+ trace_hrtimer_interrupt(raw_smp_processor_id(),
+ ktime_to_ns(ktime_sub(ktime_to_ns(timer->praecox) ?
+ timer->praecox : hrtimer_get_expires(timer),
+ basenow)),
+ current,
+ timer->function == hrtimer_wakeup ?
+ container_of(timer, struct hrtimer_sleeper,
+ timer)->task : NULL);
+
/*
* The immediate goal for using the softexpires is
* minimizing wakeups, not running timers at the
@@ -1366,7 +1604,10 @@
break;
}
- __run_hrtimer(timer, &basenow);
+ if (!hrtimer_rt_defer(timer))
+ __run_hrtimer(timer, &basenow);
+ else
+ raise = 1;
}
}
@@ -1381,7 +1622,7 @@
if (expires_next.tv64 == KTIME_MAX ||
!tick_program_event(expires_next, 0)) {
cpu_base->hang_detected = 0;
- return;
+ goto out;
}
/*
@@ -1425,6 +1666,9 @@
tick_program_event(expires_next, 1);
printk_once(KERN_WARNING "hrtimer: interrupt took %llu ns\n",
ktime_to_ns(delta));
+out:
+ if (raise)
+ raise_softirq_irqoff(HRTIMER_SOFTIRQ);
}
/*
@@ -1460,18 +1704,18 @@
__hrtimer_peek_ahead_timers();
local_irq_restore(flags);
}
-
-static void run_hrtimer_softirq(struct softirq_action *h)
-{
- hrtimer_peek_ahead_timers();
-}
-
#else /* CONFIG_HIGH_RES_TIMERS */
static inline void __hrtimer_peek_ahead_timers(void) { }
#endif /* !CONFIG_HIGH_RES_TIMERS */
+
+static void run_hrtimer_softirq(struct softirq_action *h)
+{
+ hrtimer_rt_run_pending();
+}
+
/*
* Called from timer softirq every jiffy, expire hrtimers:
*
@@ -1504,7 +1748,7 @@
struct timerqueue_node *node;
struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
struct hrtimer_clock_base *base;
- int index, gettime = 1;
+ int index, gettime = 1, raise = 0;
if (hrtimer_hres_active())
return;
@@ -1529,10 +1773,16 @@
hrtimer_get_expires_tv64(timer))
break;
- __run_hrtimer(timer, &base->softirq_time);
+ if (!hrtimer_rt_defer(timer))
+ __run_hrtimer(timer, &base->softirq_time);
+ else
+ raise = 1;
}
raw_spin_unlock(&cpu_base->lock);
}
+
+ if (raise)
+ raise_softirq_irqoff(HRTIMER_SOFTIRQ);
}
/*
@@ -1554,16 +1804,18 @@
void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
{
sl->timer.function = hrtimer_wakeup;
+ sl->timer.irqsafe = 1;
sl->task = task;
}
EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
-static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
+static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode,
+ unsigned long state)
{
hrtimer_init_sleeper(t, current);
do {
- set_current_state(TASK_INTERRUPTIBLE);
+ set_current_state(state);
hrtimer_start_expires(&t->timer, mode);
if (!hrtimer_active(&t->timer))
t->task = NULL;
@@ -1607,7 +1859,8 @@
HRTIMER_MODE_ABS);
hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
- if (do_nanosleep(&t, HRTIMER_MODE_ABS))
+ /* cpu_chill() does not care about restart state. */
+ if (do_nanosleep(&t, HRTIMER_MODE_ABS, TASK_INTERRUPTIBLE))
goto out;
rmtp = restart->nanosleep.rmtp;
@@ -1624,8 +1877,10 @@
return ret;
}
-long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
- const enum hrtimer_mode mode, const clockid_t clockid)
+static long
+__hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
+ const enum hrtimer_mode mode, const clockid_t clockid,
+ unsigned long state)
{
struct restart_block *restart;
struct hrtimer_sleeper t;
@@ -1638,7 +1893,7 @@
hrtimer_init_on_stack(&t.timer, clockid, mode);
hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
- if (do_nanosleep(&t, mode))
+ if (do_nanosleep(&t, mode, state))
goto out;
/* Absolute timers do not update the rmtp value and restart: */
@@ -1665,6 +1920,12 @@
return ret;
}
+long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
+ const enum hrtimer_mode mode, const clockid_t clockid)
+{
+ return __hrtimer_nanosleep(rqtp, rmtp, mode, clockid, TASK_INTERRUPTIBLE);
+}
+
SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
struct timespec __user *, rmtp)
{
@@ -1679,6 +1940,26 @@
return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * Sleep for 1 ms in hope whoever holds what we want will let it go.
+ */
+void cpu_chill(void)
+{
+ struct timespec tu = {
+ .tv_nsec = NSEC_PER_MSEC,
+ };
+ unsigned int freeze_flag = current->flags & PF_NOFREEZE;
+
+ current->flags |= PF_NOFREEZE;
+ __hrtimer_nanosleep(&tu, NULL, HRTIMER_MODE_REL, CLOCK_MONOTONIC,
+ TASK_UNINTERRUPTIBLE);
+ if (!freeze_flag)
+ current->flags &= ~PF_NOFREEZE;
+}
+EXPORT_SYMBOL(cpu_chill);
+#endif
+
/*
* Functions related to boot-time initialization:
*/
@@ -1690,9 +1971,13 @@
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
cpu_base->clock_base[i].cpu_base = cpu_base;
timerqueue_init_head(&cpu_base->clock_base[i].active);
+ INIT_LIST_HEAD(&cpu_base->clock_base[i].expired);
}
hrtimer_init_hres(cpu_base);
+#ifdef CONFIG_PREEMPT_RT_BASE
+ init_waitqueue_head(&cpu_base->wait);
+#endif
}
#ifdef CONFIG_HOTPLUG_CPU
@@ -1805,9 +2090,7 @@
hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
(void *)(long)smp_processor_id());
register_cpu_notifier(&hrtimers_nb);
-#ifdef CONFIG_HIGH_RES_TIMERS
open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq);
-#endif
}
/**
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 131ca17..7f50c55 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -132,6 +132,8 @@
irqreturn_t
handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
{
+ struct pt_regs *regs = get_irq_regs();
+ u64 ip = regs ? instruction_pointer(regs) : 0;
irqreturn_t retval = IRQ_NONE;
unsigned int flags = 0, irq = desc->irq_data.irq;
@@ -172,7 +174,11 @@
action = action->next;
} while (action);
- add_interrupt_randomness(irq, flags);
+#ifndef CONFIG_PREEMPT_RT_FULL
+ add_interrupt_randomness(irq, flags, ip);
+#else
+ desc->random_ip = ip;
+#endif
if (!noirqdebug)
note_interrupt(irq, desc, retval);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 504bb4b..713dcaa 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -22,6 +22,7 @@
#include "internals.h"
#ifdef CONFIG_IRQ_FORCED_THREADING
+# ifndef CONFIG_PREEMPT_RT_BASE
__read_mostly bool force_irqthreads;
static int __init setup_forced_irqthreads(char *arg)
@@ -30,6 +31,7 @@
return 0;
}
early_param("threadirqs", setup_forced_irqthreads);
+# endif
#endif
/**
@@ -162,6 +164,62 @@
return ret;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void _irq_affinity_notify(struct irq_affinity_notify *notify);
+static struct task_struct *set_affinity_helper;
+static LIST_HEAD(affinity_list);
+static DEFINE_RAW_SPINLOCK(affinity_list_lock);
+
+static int set_affinity_thread(void *unused)
+{
+ while (1) {
+ struct irq_affinity_notify *notify;
+ int empty;
+
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ raw_spin_lock_irq(&affinity_list_lock);
+ empty = list_empty(&affinity_list);
+ raw_spin_unlock_irq(&affinity_list_lock);
+
+ if (empty)
+ schedule();
+ if (kthread_should_stop())
+ break;
+ set_current_state(TASK_RUNNING);
+try_next:
+ notify = NULL;
+
+ raw_spin_lock_irq(&affinity_list_lock);
+ if (!list_empty(&affinity_list)) {
+ notify = list_first_entry(&affinity_list,
+ struct irq_affinity_notify, list);
+ list_del_init(¬ify->list);
+ }
+ raw_spin_unlock_irq(&affinity_list_lock);
+
+ if (!notify)
+ continue;
+ _irq_affinity_notify(notify);
+ goto try_next;
+ }
+ return 0;
+}
+
+static void init_helper_thread(void)
+{
+ if (set_affinity_helper)
+ return;
+ set_affinity_helper = kthread_run(set_affinity_thread, NULL,
+ "affinity-cb");
+ WARN_ON(IS_ERR(set_affinity_helper));
+}
+#else
+
+static inline void init_helper_thread(void) { }
+
+#endif
+
int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
bool force)
{
@@ -181,7 +239,17 @@
if (desc->affinity_notify) {
kref_get(&desc->affinity_notify->kref);
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+ raw_spin_lock(&affinity_list_lock);
+ if (list_empty(&desc->affinity_notify->list))
+ list_add_tail(&affinity_list,
+ &desc->affinity_notify->list);
+ raw_spin_unlock(&affinity_list_lock);
+ wake_up_process(set_affinity_helper);
+#else
schedule_work(&desc->affinity_notify->work);
+#endif
}
irqd_set(data, IRQD_AFFINITY_SET);
@@ -216,10 +284,8 @@
}
EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
-static void irq_affinity_notify(struct work_struct *work)
+static void _irq_affinity_notify(struct irq_affinity_notify *notify)
{
- struct irq_affinity_notify *notify =
- container_of(work, struct irq_affinity_notify, work);
struct irq_desc *desc = irq_to_desc(notify->irq);
cpumask_var_t cpumask;
unsigned long flags;
@@ -241,6 +307,13 @@
kref_put(¬ify->kref, notify->release);
}
+static void irq_affinity_notify(struct work_struct *work)
+{
+ struct irq_affinity_notify *notify =
+ container_of(work, struct irq_affinity_notify, work);
+ _irq_affinity_notify(notify);
+}
+
/**
* irq_set_affinity_notifier - control notification of IRQ affinity changes
* @irq: Interrupt for which to enable/disable notification
@@ -270,6 +343,8 @@
notify->irq = irq;
kref_init(¬ify->kref);
INIT_WORK(¬ify->work, irq_affinity_notify);
+ INIT_LIST_HEAD(¬ify->list);
+ init_helper_thread();
}
raw_spin_lock_irqsave(&desc->lock, flags);
@@ -776,7 +851,15 @@
local_bh_disable();
ret = action->thread_fn(action->irq, action->dev_id);
irq_finalize_oneshot(desc, action);
- local_bh_enable();
+ /*
+ * Interrupts which have real time requirements can be set up
+ * to avoid softirq processing in the thread handler. This is
+ * safe as these interrupts do not raise soft interrupts.
+ */
+ if (irq_settings_no_softirq_call(desc))
+ _local_bh_enable();
+ else
+ local_bh_enable();
return ret;
}
@@ -859,6 +942,12 @@
if (action_ret == IRQ_HANDLED)
atomic_inc(&desc->threads_handled);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ migrate_disable();
+ add_interrupt_randomness(action->irq, 0,
+ desc->random_ip ^ (unsigned long) action);
+ migrate_enable();
+#endif
wake_threads_waitq(desc);
}
@@ -1121,6 +1210,9 @@
irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
}
+ if (new->flags & IRQF_NO_SOFTIRQ_CALL)
+ irq_settings_set_no_softirq_call(desc);
+
/* Set default affinity mask once everything is setup */
setup_affinity(irq, desc, mask);
diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h
index 1162f10..0d2c381 100644
--- a/kernel/irq/settings.h
+++ b/kernel/irq/settings.h
@@ -14,6 +14,7 @@
_IRQ_NO_BALANCING = IRQ_NO_BALANCING,
_IRQ_NESTED_THREAD = IRQ_NESTED_THREAD,
_IRQ_PER_CPU_DEVID = IRQ_PER_CPU_DEVID,
+ _IRQ_NO_SOFTIRQ_CALL = IRQ_NO_SOFTIRQ_CALL,
_IRQF_MODIFY_MASK = IRQF_MODIFY_MASK,
};
@@ -26,6 +27,7 @@
#define IRQ_NOAUTOEN GOT_YOU_MORON
#define IRQ_NESTED_THREAD GOT_YOU_MORON
#define IRQ_PER_CPU_DEVID GOT_YOU_MORON
+#define IRQ_NO_SOFTIRQ_CALL GOT_YOU_MORON
#undef IRQF_MODIFY_MASK
#define IRQF_MODIFY_MASK GOT_YOU_MORON
@@ -36,6 +38,16 @@
desc->status_use_accessors |= (set & _IRQF_MODIFY_MASK);
}
+static inline bool irq_settings_no_softirq_call(struct irq_desc *desc)
+{
+ return desc->status_use_accessors & _IRQ_NO_SOFTIRQ_CALL;
+}
+
+static inline void irq_settings_set_no_softirq_call(struct irq_desc *desc)
+{
+ desc->status_use_accessors |= _IRQ_NO_SOFTIRQ_CALL;
+}
+
static inline bool irq_settings_is_per_cpu(struct irq_desc *desc)
{
return desc->status_use_accessors & _IRQ_PER_CPU;
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index febcee3c..ca47be0 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -438,6 +438,10 @@
static int __init irqfixup_setup(char *str)
{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ pr_warn("irqfixup boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n");
+ return 1;
+#endif
irqfixup = 1;
printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
printk(KERN_WARNING "This may impact system performance.\n");
@@ -450,6 +454,10 @@
static int __init irqpoll_setup(char *str)
{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ pr_warn("irqpoll boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n");
+ return 1;
+#endif
irqfixup = 2;
printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
"enabled\n");
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 55fcce6..883bb73 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -16,11 +16,12 @@
#include <linux/tick.h>
#include <linux/cpu.h>
#include <linux/notifier.h>
+#include <linux/interrupt.h>
#include <asm/processor.h>
-static DEFINE_PER_CPU(struct llist_head, irq_work_list);
-static DEFINE_PER_CPU(int, irq_work_raised);
+static DEFINE_PER_CPU(struct llist_head, raised_list);
+static DEFINE_PER_CPU(struct llist_head, lazy_list);
/*
* Claim the entry so that no one else will poke at it.
@@ -63,6 +64,9 @@
*/
void irq_work_queue(struct irq_work *work)
{
+ bool lazy_work, realtime = IS_ENABLED(CONFIG_PREEMPT_RT_FULL);
+ struct llist_head *list;
+
/* Only queue if not already pending */
if (!irq_work_claim(work))
return;
@@ -70,15 +74,16 @@
/* Queue the entry and raise the IPI if needed. */
preempt_disable();
- llist_add(&work->llnode, &__get_cpu_var(irq_work_list));
+ /* If the work is "lazy", handle it from next tick if any */
+ lazy_work = work->flags & IRQ_WORK_LAZY;
- /*
- * If the work is not "lazy" or the tick is stopped, raise the irq
- * work interrupt (if supported by the arch), otherwise, just wait
- * for the next tick.
- */
- if (!(work->flags & IRQ_WORK_LAZY) || tick_nohz_tick_stopped()) {
- if (!this_cpu_cmpxchg(irq_work_raised, 0, 1))
+ if (lazy_work || (realtime && !(work->flags & IRQ_WORK_HARD_IRQ)))
+ list = this_cpu_ptr(&lazy_list);
+ else
+ list = this_cpu_ptr(&raised_list);
+
+ if (llist_add(&work->llnode, list)) {
+ if (!lazy_work || tick_nohz_tick_stopped())
arch_irq_work_raise();
}
@@ -88,10 +93,11 @@
bool irq_work_needs_cpu(void)
{
- struct llist_head *this_list;
+ struct llist_head *raised, *lazy;
- this_list = &__get_cpu_var(irq_work_list);
- if (llist_empty(this_list))
+ raised = &__get_cpu_var(raised_list);
+ lazy = &__get_cpu_var(lazy_list);
+ if (llist_empty(raised) && llist_empty(lazy))
return false;
/* All work should have been flushed before going offline */
@@ -100,28 +106,18 @@
return true;
}
-static void __irq_work_run(void)
+static void irq_work_run_list(struct llist_head *list)
{
unsigned long flags;
struct irq_work *work;
- struct llist_head *this_list;
struct llist_node *llnode;
+ BUG_ON_NONRT(!irqs_disabled());
- /*
- * Reset the "raised" state right before we check the list because
- * an NMI may enqueue after we find the list empty from the runner.
- */
- __this_cpu_write(irq_work_raised, 0);
- barrier();
-
- this_list = &__get_cpu_var(irq_work_list);
- if (llist_empty(this_list))
+ if (llist_empty(list))
return;
- BUG_ON(!irqs_disabled());
-
- llnode = llist_del_all(this_list);
+ llnode = llist_del_all(list);
while (llnode != NULL) {
work = llist_entry(llnode, struct irq_work, llnode);
@@ -152,11 +148,33 @@
*/
void irq_work_run(void)
{
- BUG_ON(!in_irq());
- __irq_work_run();
+ irq_work_run_list(this_cpu_ptr(&raised_list));
+ if (IS_ENABLED(CONFIG_PREEMPT_RT_FULL)) {
+ if (!llist_empty(this_cpu_ptr(&lazy_list)))
+ raise_softirq(TIMER_SOFTIRQ);
+ } else
+ irq_work_run_list(this_cpu_ptr(&lazy_list));
}
EXPORT_SYMBOL_GPL(irq_work_run);
+void irq_work_tick(void)
+{
+ struct llist_head *raised = this_cpu_ptr(&raised_list);
+
+ if (!llist_empty(raised) && !arch_irq_work_has_interrupt())
+ irq_work_run_list(raised);
+
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL))
+ irq_work_run_list(this_cpu_ptr(&lazy_list));
+}
+
+#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
+void irq_work_tick_soft(void)
+{
+ irq_work_run_list(this_cpu_ptr(&lazy_list));
+}
+#endif
+
/*
* Synchronize against the irq_work @entry, ensures the entry is not
* currently in use.
@@ -181,7 +199,7 @@
/* Called from stop_machine */
if (WARN_ON_ONCE(cpu != smp_processor_id()))
break;
- __irq_work_run();
+ irq_work_tick();
break;
default:
break;
diff --git a/kernel/itimer.c b/kernel/itimer.c
index 8d262b4..d051390 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -213,6 +213,7 @@
/* We are sharing ->siglock with it_real_fn() */
if (hrtimer_try_to_cancel(timer) < 0) {
spin_unlock_irq(&tsk->sighand->siglock);
+ hrtimer_wait_for_timer(&tsk->signal->real_timer);
goto again;
}
expires = timeval_to_ktime(value->it_value);
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 9659d38..b66ab9e 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -132,6 +132,15 @@
#endif /* CONFIG_KEXEC */
+#if defined(CONFIG_PREEMPT_RT_FULL)
+static ssize_t realtime_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", 1);
+}
+KERNEL_ATTR_RO(realtime);
+#endif
+
/* whether file capabilities are enabled */
static ssize_t fscaps_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
@@ -197,6 +206,9 @@
&vmcoreinfo_attr.attr,
#endif
&rcu_expedited_attr.attr,
+#ifdef CONFIG_PREEMPT_RT_FULL
+ &realtime_attr.attr,
+#endif
NULL
};
diff --git a/kernel/lglock.c b/kernel/lglock.c
index 86ae2ae..f2356df 100644
--- a/kernel/lglock.c
+++ b/kernel/lglock.c
@@ -4,6 +4,15 @@
#include <linux/cpu.h>
#include <linux/string.h>
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define lg_lock_ptr arch_spinlock_t
+# define lg_do_lock(l) arch_spin_lock(l)
+# define lg_do_unlock(l) arch_spin_unlock(l)
+#else
+# define lg_lock_ptr struct rt_mutex
+# define lg_do_lock(l) __rt_spin_lock(l)
+# define lg_do_unlock(l) __rt_spin_unlock(l)
+#endif
/*
* Note there is no uninit, so lglocks cannot be defined in
* modules (but it's fine to use them from there)
@@ -12,51 +21,60 @@
void lg_lock_init(struct lglock *lg, char *name)
{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ int i;
+
+ for_each_possible_cpu(i) {
+ struct rt_mutex *lock = per_cpu_ptr(lg->lock, i);
+
+ rt_mutex_init(lock);
+ }
+#endif
LOCKDEP_INIT_MAP(&lg->lock_dep_map, name, &lg->lock_key, 0);
}
EXPORT_SYMBOL(lg_lock_init);
void lg_local_lock(struct lglock *lg)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
- preempt_disable();
+ migrate_disable();
lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
lock = this_cpu_ptr(lg->lock);
- arch_spin_lock(lock);
+ lg_do_lock(lock);
}
EXPORT_SYMBOL(lg_local_lock);
void lg_local_unlock(struct lglock *lg)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock_release(&lg->lock_dep_map, 1, _RET_IP_);
lock = this_cpu_ptr(lg->lock);
- arch_spin_unlock(lock);
- preempt_enable();
+ lg_do_unlock(lock);
+ migrate_enable();
}
EXPORT_SYMBOL(lg_local_unlock);
void lg_local_lock_cpu(struct lglock *lg, int cpu)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
- preempt_disable();
+ preempt_disable_nort();
lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
lock = per_cpu_ptr(lg->lock, cpu);
- arch_spin_lock(lock);
+ lg_do_lock(lock);
}
EXPORT_SYMBOL(lg_local_lock_cpu);
void lg_local_unlock_cpu(struct lglock *lg, int cpu)
{
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock_release(&lg->lock_dep_map, 1, _RET_IP_);
lock = per_cpu_ptr(lg->lock, cpu);
- arch_spin_unlock(lock);
- preempt_enable();
+ lg_do_unlock(lock);
+ preempt_enable_nort();
}
EXPORT_SYMBOL(lg_local_unlock_cpu);
@@ -64,12 +82,12 @@
{
int i;
- preempt_disable();
+ preempt_disable_nort();
lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
for_each_possible_cpu(i) {
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock = per_cpu_ptr(lg->lock, i);
- arch_spin_lock(lock);
+ lg_do_lock(lock);
}
}
EXPORT_SYMBOL(lg_global_lock);
@@ -80,10 +98,10 @@
lock_release(&lg->lock_dep_map, 1, _RET_IP_);
for_each_possible_cpu(i) {
- arch_spinlock_t *lock;
+ lg_lock_ptr *lock;
lock = per_cpu_ptr(lg->lock, i);
- arch_spin_unlock(lock);
+ lg_do_unlock(lock);
}
- preempt_enable();
+ preempt_enable_nort();
}
EXPORT_SYMBOL(lg_global_unlock);
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index e16c45b..dadf83f 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -650,6 +650,7 @@
struct lockdep_subclass_key *key;
struct list_head *hash_head;
struct lock_class *class;
+ bool is_static = false;
#ifdef CONFIG_DEBUG_LOCKDEP
/*
@@ -677,10 +678,23 @@
/*
* Static locks do not have their class-keys yet - for them the key
- * is the lock object itself:
+ * is the lock object itself. If the lock is in the per cpu area,
+ * the canonical address of the lock (per cpu offset removed) is
+ * used.
*/
- if (unlikely(!lock->key))
- lock->key = (void *)lock;
+ if (unlikely(!lock->key)) {
+ unsigned long can_addr, addr = (unsigned long)lock;
+
+ if (__is_kernel_percpu_address(addr, &can_addr))
+ lock->key = (void *)can_addr;
+ else if (__is_module_percpu_address(addr, &can_addr))
+ lock->key = (void *)can_addr;
+ else if (static_obj(lock))
+ lock->key = (void *)lock;
+ else
+ return ERR_PTR(-EINVAL);
+ is_static = true;
+ }
/*
* NOTE: the class-key must be unique. For dynamic locks, a static
@@ -710,7 +724,7 @@
}
}
- return NULL;
+ return is_static || static_obj(lock->key) ? NULL : ERR_PTR(-EINVAL);
}
/*
@@ -727,13 +741,13 @@
unsigned long flags;
class = look_up_lock_class(lock, subclass);
- if (likely(class))
+ if (likely(!IS_ERR_OR_NULL(class)))
goto out_set_class_cache;
/*
* Debug-check: all keys must be persistent!
- */
- if (!static_obj(lock->key)) {
+ */
+ if (IS_ERR(class)) {
debug_locks_off();
printk("INFO: trying to register non-static key.\n");
printk("the code is fine but needs lockdep annotation.\n");
@@ -3275,7 +3289,7 @@
* Clearly if the lock hasn't been acquired _ever_, we're not
* holding it either, so report failure.
*/
- if (!class)
+ if (IS_ERR_OR_NULL(class))
return 0;
/*
@@ -3541,6 +3555,7 @@
}
}
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* We dont accurately track softirq state in e.g.
* hardirq contexts (such as on 4KSTACKS), so only
@@ -3555,6 +3570,7 @@
DEBUG_LOCKS_WARN_ON(!current->softirqs_enabled);
}
}
+#endif
if (!debug_locks)
print_irqtrace_events(current);
@@ -3935,7 +3951,7 @@
* If the class exists we look it up and zap it:
*/
class = look_up_lock_class(lock, j);
- if (class)
+ if (!IS_ERR_OR_NULL(class))
zap_class(class);
}
/*
diff --git a/kernel/module.c b/kernel/module.c
index a8c4d41..64135e9 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -530,16 +530,7 @@
memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
}
-/**
- * is_module_percpu_address - test whether address is from module static percpu
- * @addr: address to test
- *
- * Test whether @addr belongs to module static percpu area.
- *
- * RETURNS:
- * %true if @addr is from module static percpu area
- */
-bool is_module_percpu_address(unsigned long addr)
+bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
{
struct module *mod;
unsigned int cpu;
@@ -553,9 +544,11 @@
continue;
for_each_possible_cpu(cpu) {
void *start = per_cpu_ptr(mod->percpu, cpu);
+ void *va = (void *)addr;
- if ((void *)addr >= start &&
- (void *)addr < start + mod->percpu_size) {
+ if (va >= start && va < start + mod->percpu_size) {
+ if (can_addr)
+ *can_addr = (unsigned long) (va - start);
preempt_enable();
return true;
}
@@ -566,6 +559,20 @@
return false;
}
+/**
+ * is_module_percpu_address - test whether address is from module static percpu
+ * @addr: address to test
+ *
+ * Test whether @addr belongs to module static percpu area.
+ *
+ * RETURNS:
+ * %true if @addr is from module static percpu area
+ */
+bool is_module_percpu_address(unsigned long addr)
+{
+ return __is_module_percpu_address(addr, NULL);
+}
+
#else /* ... !CONFIG_SMP */
static inline void __percpu *mod_percpu(struct module *mod)
@@ -597,6 +604,11 @@
return false;
}
+bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
+{
+ return false;
+}
+
#endif /* CONFIG_SMP */
#define MODINFO_ATTR(field) \
diff --git a/kernel/panic.c b/kernel/panic.c
index 639255d..232bca8 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -380,9 +380,11 @@
static int init_oops_id(void)
{
+#ifndef CONFIG_PREEMPT_RT_FULL
if (!oops_id)
get_random_bytes(&oops_id, sizeof(oops_id));
else
+#endif
oops_id++;
return 0;
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index c7f31aa..4bf82f8 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -3,6 +3,7 @@
*/
#include <linux/sched.h>
+#include <linux/sched/rt.h>
#include <linux/posix-timers.h>
#include <linux/errno.h>
#include <linux/math64.h>
@@ -663,7 +664,7 @@
/*
* Disarm any old timer after extracting its expiry time.
*/
- BUG_ON(!irqs_disabled());
+ BUG_ON_NONRT(!irqs_disabled());
ret = 0;
old_incr = timer->it.cpu.incr;
@@ -1110,7 +1111,7 @@
/*
* Now re-arm for the new expiry time.
*/
- BUG_ON(!irqs_disabled());
+ BUG_ON_NONRT(!irqs_disabled());
arm_timer(timer);
spin_unlock(&p->sighand->siglock);
@@ -1177,10 +1178,11 @@
sig = tsk->signal;
if (sig->cputimer.running) {
struct task_cputime group_sample;
+ unsigned long flags;
- raw_spin_lock(&sig->cputimer.lock);
+ raw_spin_lock_irqsave(&sig->cputimer.lock, flags);
group_sample = sig->cputimer.cputime;
- raw_spin_unlock(&sig->cputimer.lock);
+ raw_spin_unlock_irqrestore(&sig->cputimer.lock, flags);
if (task_cputime_expired(&group_sample, &sig->cputime_expires))
return 1;
@@ -1194,13 +1196,13 @@
* already updated our counts. We need to check if any timers fire now.
* Interrupts are disabled.
*/
-void run_posix_cpu_timers(struct task_struct *tsk)
+static void __run_posix_cpu_timers(struct task_struct *tsk)
{
LIST_HEAD(firing);
struct k_itimer *timer, *next;
unsigned long flags;
- BUG_ON(!irqs_disabled());
+ BUG_ON_NONRT(!irqs_disabled());
/*
* The fast path checks that there are no expired thread or thread
@@ -1265,6 +1267,190 @@
posix_cpu_timer_kick_nohz();
}
+#ifdef CONFIG_PREEMPT_RT_BASE
+#include <linux/kthread.h>
+#include <linux/cpu.h>
+DEFINE_PER_CPU(struct task_struct *, posix_timer_task);
+DEFINE_PER_CPU(struct task_struct *, posix_timer_tasklist);
+
+static int posix_cpu_timers_thread(void *data)
+{
+ int cpu = (long)data;
+
+ BUG_ON(per_cpu(posix_timer_task,cpu) != current);
+
+ while (!kthread_should_stop()) {
+ struct task_struct *tsk = NULL;
+ struct task_struct *next = NULL;
+
+ if (cpu_is_offline(cpu))
+ goto wait_to_die;
+
+ /* grab task list */
+ raw_local_irq_disable();
+ tsk = per_cpu(posix_timer_tasklist, cpu);
+ per_cpu(posix_timer_tasklist, cpu) = NULL;
+ raw_local_irq_enable();
+
+ /* its possible the list is empty, just return */
+ if (!tsk) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ __set_current_state(TASK_RUNNING);
+ continue;
+ }
+
+ /* Process task list */
+ while (1) {
+ /* save next */
+ next = tsk->posix_timer_list;
+
+ /* run the task timers, clear its ptr and
+ * unreference it
+ */
+ __run_posix_cpu_timers(tsk);
+ tsk->posix_timer_list = NULL;
+ put_task_struct(tsk);
+
+ /* check if this is the last on the list */
+ if (next == tsk)
+ break;
+ tsk = next;
+ }
+ }
+ return 0;
+
+wait_to_die:
+ /* Wait for kthread_stop */
+ set_current_state(TASK_INTERRUPTIBLE);
+ while (!kthread_should_stop()) {
+ schedule();
+ set_current_state(TASK_INTERRUPTIBLE);
+ }
+ __set_current_state(TASK_RUNNING);
+ return 0;
+}
+
+static inline int __fastpath_timer_check(struct task_struct *tsk)
+{
+ /* tsk == current, ensure it is safe to use ->signal/sighand */
+ if (unlikely(tsk->exit_state))
+ return 0;
+
+ if (!task_cputime_zero(&tsk->cputime_expires))
+ return 1;
+
+ if (!task_cputime_zero(&tsk->signal->cputime_expires))
+ return 1;
+
+ return 0;
+}
+
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+ unsigned long cpu = smp_processor_id();
+ struct task_struct *tasklist;
+
+ BUG_ON(!irqs_disabled());
+ if(!per_cpu(posix_timer_task, cpu))
+ return;
+ /* get per-cpu references */
+ tasklist = per_cpu(posix_timer_tasklist, cpu);
+
+ /* check to see if we're already queued */
+ if (!tsk->posix_timer_list && __fastpath_timer_check(tsk)) {
+ get_task_struct(tsk);
+ if (tasklist) {
+ tsk->posix_timer_list = tasklist;
+ } else {
+ /*
+ * The list is terminated by a self-pointing
+ * task_struct
+ */
+ tsk->posix_timer_list = tsk;
+ }
+ per_cpu(posix_timer_tasklist, cpu) = tsk;
+
+ wake_up_process(per_cpu(posix_timer_task, cpu));
+ }
+}
+
+/*
+ * posix_cpu_thread_call - callback that gets triggered when a CPU is added.
+ * Here we can start up the necessary migration thread for the new CPU.
+ */
+static int posix_cpu_thread_call(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ int cpu = (long)hcpu;
+ struct task_struct *p;
+ struct sched_param param;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ p = kthread_create(posix_cpu_timers_thread, hcpu,
+ "posixcputmr/%d",cpu);
+ if (IS_ERR(p))
+ return NOTIFY_BAD;
+ p->flags |= PF_NOFREEZE;
+ kthread_bind(p, cpu);
+ /* Must be high prio to avoid getting starved */
+ param.sched_priority = MAX_RT_PRIO-1;
+ sched_setscheduler(p, SCHED_FIFO, ¶m);
+ per_cpu(posix_timer_task,cpu) = p;
+ break;
+ case CPU_ONLINE:
+ /* Strictly unneccessary, as first user will wake it. */
+ wake_up_process(per_cpu(posix_timer_task,cpu));
+ break;
+#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_UP_CANCELED:
+ /* Unbind it from offline cpu so it can run. Fall thru. */
+ kthread_bind(per_cpu(posix_timer_task, cpu),
+ cpumask_any(cpu_online_mask));
+ kthread_stop(per_cpu(posix_timer_task,cpu));
+ per_cpu(posix_timer_task,cpu) = NULL;
+ break;
+ case CPU_DEAD:
+ kthread_stop(per_cpu(posix_timer_task,cpu));
+ per_cpu(posix_timer_task,cpu) = NULL;
+ break;
+#endif
+ }
+ return NOTIFY_OK;
+}
+
+/* Register at highest priority so that task migration (migrate_all_tasks)
+ * happens before everything else.
+ */
+static struct notifier_block posix_cpu_thread_notifier = {
+ .notifier_call = posix_cpu_thread_call,
+ .priority = 10
+};
+
+static int __init posix_cpu_thread_init(void)
+{
+ void *hcpu = (void *)(long)smp_processor_id();
+ /* Start one for boot CPU. */
+ unsigned long cpu;
+
+ /* init the per-cpu posix_timer_tasklets */
+ for_each_possible_cpu(cpu)
+ per_cpu(posix_timer_tasklist, cpu) = NULL;
+
+ posix_cpu_thread_call(&posix_cpu_thread_notifier, CPU_UP_PREPARE, hcpu);
+ posix_cpu_thread_call(&posix_cpu_thread_notifier, CPU_ONLINE, hcpu);
+ register_cpu_notifier(&posix_cpu_thread_notifier);
+ return 0;
+}
+early_initcall(posix_cpu_thread_init);
+#else /* CONFIG_PREEMPT_RT_BASE */
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+ __run_posix_cpu_timers(tsk);
+}
+#endif /* CONFIG_PREEMPT_RT_BASE */
+
/*
* Set one of the process-wide special case CPU timers or RLIMIT_CPU.
* The tsk->sighand->siglock must be held by the caller.
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 77e6b83..5218a7d 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -497,6 +497,7 @@
static struct pid *good_sigevent(sigevent_t * event)
{
struct task_struct *rtn = current->group_leader;
+ int sig = event->sigev_signo;
if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
(!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
@@ -505,7 +506,8 @@
return NULL;
if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
- ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
+ (sig <= 0 || sig > SIGRTMAX || sig_kernel_only(sig) ||
+ sig_kernel_coredump(sig)))
return NULL;
return task_pid(rtn);
@@ -817,6 +819,20 @@
return overrun;
}
+/*
+ * Protected by RCU!
+ */
+static void timer_wait_for_callback(struct k_clock *kc, struct k_itimer *timr)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (kc->timer_set == common_timer_set)
+ hrtimer_wait_for_timer(&timr->it.real.timer);
+ else
+ /* FIXME: Whacky hack for posix-cpu-timers */
+ schedule_timeout(1);
+#endif
+}
+
/* Set a POSIX.1b interval timer. */
/* timr->it_lock is taken. */
static int
@@ -894,6 +910,7 @@
if (!timr)
return -EINVAL;
+ rcu_read_lock();
kc = clockid_to_kclock(timr->it_clock);
if (WARN_ON_ONCE(!kc || !kc->timer_set))
error = -EINVAL;
@@ -902,9 +919,12 @@
unlock_timer(timr, flag);
if (error == TIMER_RETRY) {
+ timer_wait_for_callback(kc, timr);
rtn = NULL; // We already got the old time...
+ rcu_read_unlock();
goto retry;
}
+ rcu_read_unlock();
if (old_setting && !error &&
copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
@@ -942,10 +962,15 @@
if (!timer)
return -EINVAL;
+ rcu_read_lock();
if (timer_delete_hook(timer) == TIMER_RETRY) {
unlock_timer(timer, flags);
+ timer_wait_for_callback(clockid_to_kclock(timer->it_clock),
+ timer);
+ rcu_read_unlock();
goto retry_delete;
}
+ rcu_read_unlock();
spin_lock(¤t->sighand->siglock);
list_del(&timer->list);
@@ -971,8 +996,18 @@
retry_delete:
spin_lock_irqsave(&timer->it_lock, flags);
- if (timer_delete_hook(timer) == TIMER_RETRY) {
+ /* On RT we can race with a deletion */
+ if (!timer->it_signal) {
unlock_timer(timer, flags);
+ return;
+ }
+
+ if (timer_delete_hook(timer) == TIMER_RETRY) {
+ rcu_read_lock();
+ unlock_timer(timer, flags);
+ timer_wait_for_callback(clockid_to_kclock(timer->it_clock),
+ timer);
+ rcu_read_unlock();
goto retry_delete;
}
list_del(&timer->list);
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 7ef5244..9c312ed 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -275,6 +275,8 @@
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
+
error = syscore_suspend();
if (error) {
printk(KERN_ERR "PM: Some system devices failed to power down, "
@@ -302,6 +304,7 @@
syscore_resume();
Enable_irqs:
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
@@ -427,6 +430,7 @@
goto Enable_cpus;
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
error = syscore_suspend();
if (error)
@@ -460,6 +464,7 @@
syscore_resume();
Enable_irqs:
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
@@ -548,6 +553,7 @@
goto Platform_finish;
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
syscore_suspend();
if (pm_wakeup_pending()) {
error = -EAGAIN;
@@ -560,6 +566,7 @@
Power_up:
syscore_resume();
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
enable_nonboot_cpus();
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 5455d5c..c2372ed 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -210,6 +210,8 @@
arch_suspend_disable_irqs();
BUG_ON(!irqs_disabled());
+ system_state = SYSTEM_SUSPEND;
+
error = syscore_suspend();
if (!error) {
*wakeup = pm_wakeup_pending();
@@ -220,6 +222,8 @@
syscore_resume();
}
+ system_state = SYSTEM_RUNNING;
+
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 1c03157..feba818 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1030,6 +1030,7 @@
{
char *text;
int len = 0;
+ int attempts = 0;
text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
if (!text)
@@ -1041,7 +1042,14 @@
u64 seq;
u32 idx;
enum log_flags prev;
-
+ int num_msg;
+try_again:
+ attempts++;
+ if (attempts > 10) {
+ len = -EBUSY;
+ goto out;
+ }
+ num_msg = 0;
if (clear_seq < log_first_seq) {
/* messages are gone, move to first available one */
clear_seq = log_first_seq;
@@ -1062,6 +1070,14 @@
prev = msg->flags;
idx = log_next(idx);
seq++;
+ num_msg++;
+ if (num_msg > 5) {
+ num_msg = 0;
+ raw_spin_unlock_irq(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
+ if (clear_seq < log_first_seq)
+ goto try_again;
+ }
}
/* move first record forward until length fits into the buffer */
@@ -1075,6 +1091,14 @@
prev = msg->flags;
idx = log_next(idx);
seq++;
+ num_msg++;
+ if (num_msg > 5) {
+ num_msg = 0;
+ raw_spin_unlock_irq(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
+ if (clear_seq < log_first_seq)
+ goto try_again;
+ }
}
/* last message fitting into this dump */
@@ -1115,6 +1139,7 @@
clear_seq = log_next_seq;
clear_idx = log_next_idx;
}
+out:
raw_spin_unlock_irq(&logbuf_lock);
kfree(text);
@@ -1268,6 +1293,12 @@
if (!console_drivers)
return;
+ if (IS_ENABLED(CONFIG_PREEMPT_RT_BASE)) {
+ if (in_irq() || in_nmi())
+ return;
+ }
+
+ migrate_disable();
for_each_console(con) {
if (exclusive_console && con != exclusive_console)
continue;
@@ -1280,6 +1311,7 @@
continue;
con->write(con, text, len);
}
+ migrate_enable();
}
/*
@@ -1339,12 +1371,18 @@
* interrupts disabled. It should return with 'lockbuf_lock'
* released but interrupts still disabled.
*/
-static int console_trylock_for_printk(unsigned int cpu)
+static int console_trylock_for_printk(unsigned int cpu, unsigned long flags)
__releases(&logbuf_lock)
{
int retval = 0, wake = 0;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ int lock = !early_boot_irqs_disabled && !irqs_disabled_flags(flags) &&
+ (preempt_count() <= 1);
+#else
+ int lock = 1;
+#endif
- if (console_trylock()) {
+ if (lock && console_trylock()) {
retval = 1;
/*
@@ -1484,6 +1522,62 @@
return textlen;
}
+#ifdef CONFIG_EARLY_PRINTK
+struct console *early_console;
+
+void early_vprintk(const char *fmt, va_list ap)
+{
+ if (early_console) {
+ char buf[512];
+ int n = vscnprintf(buf, sizeof(buf), fmt, ap);
+
+ early_console->write(early_console, buf, n);
+ }
+}
+
+asmlinkage void early_printk(const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ early_vprintk(fmt, ap);
+ va_end(ap);
+}
+
+/*
+ * This is independent of any log levels - a global
+ * kill switch that turns off all of printk.
+ *
+ * Used by the NMI watchdog if early-printk is enabled.
+ */
+static bool __read_mostly printk_killswitch;
+
+static int __init force_early_printk_setup(char *str)
+{
+ printk_killswitch = true;
+ return 0;
+}
+early_param("force_early_printk", force_early_printk_setup);
+
+void printk_kill(void)
+{
+ printk_killswitch = true;
+}
+
+static int forced_early_printk(const char *fmt, va_list ap)
+{
+ if (!printk_killswitch)
+ return 0;
+ early_vprintk(fmt, ap);
+ return 1;
+}
+#else
+static inline int forced_early_printk(const char *fmt, va_list ap)
+{
+ return 0;
+}
+#endif
+
asmlinkage int vprintk_emit(int facility, int level,
const char *dict, size_t dictlen,
const char *fmt, va_list args)
@@ -1497,6 +1591,13 @@
int this_cpu;
int printed_len = 0;
+ /*
+ * Fall back to early_printk if a debugging subsystem has
+ * killed printk output
+ */
+ if (unlikely(forced_early_printk(fmt, args)))
+ return 1;
+
boot_delay_msec(level);
printk_delay();
@@ -1616,8 +1717,15 @@
* The console_trylock_for_printk() function will release 'logbuf_lock'
* regardless of whether it actually gets the console semaphore or not.
*/
- if (console_trylock_for_printk(this_cpu))
+ if (console_trylock_for_printk(this_cpu, flags)) {
+#ifndef CONFIG_PREEMPT_RT_FULL
console_unlock();
+#else
+ raw_local_irq_restore(flags);
+ console_unlock();
+ raw_local_irq_save(flags);
+#endif
+ }
lockdep_on();
out_restore_irqs:
@@ -1719,29 +1827,6 @@
#endif /* CONFIG_PRINTK */
-#ifdef CONFIG_EARLY_PRINTK
-struct console *early_console;
-
-void early_vprintk(const char *fmt, va_list ap)
-{
- if (early_console) {
- char buf[512];
- int n = vscnprintf(buf, sizeof(buf), fmt, ap);
-
- early_console->write(early_console, buf, n);
- }
-}
-
-asmlinkage void early_printk(const char *fmt, ...)
-{
- va_list ap;
-
- va_start(ap, fmt);
- early_vprintk(fmt, ap);
- va_end(ap);
-}
-#endif
-
static int __add_preferred_console(char *name, int idx, char *options,
char *brl_options)
{
@@ -1982,11 +2067,16 @@
goto out;
len = cont_print_text(text, size);
+#ifndef CONFIG_PREEMPT_RT_FULL
raw_spin_unlock(&logbuf_lock);
stop_critical_timings();
call_console_drivers(cont.level, text, len);
start_critical_timings();
local_irq_restore(flags);
+#else
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+ call_console_drivers(cont.level, text, len);
+#endif
return;
out:
raw_spin_unlock_irqrestore(&logbuf_lock, flags);
@@ -2080,13 +2170,17 @@
console_idx = log_next(console_idx);
console_seq++;
console_prev = msg->flags;
- raw_spin_unlock(&logbuf_lock);
+#ifndef CONFIG_PREEMPT_RT_FULL
+ raw_spin_unlock(&logbuf_lock);
stop_critical_timings(); /* don't trace print latency */
call_console_drivers(level, text, len);
start_critical_timings();
local_irq_restore(flags);
-
+#else
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+ call_console_drivers(level, text, len);
+#endif
if (do_cond_resched)
cond_resched();
}
@@ -2139,6 +2233,11 @@
{
struct console *c;
+ if (IS_ENABLED(CONFIG_PREEMPT_RT_BASE)) {
+ if (in_irq() || in_nmi())
+ return;
+ }
+
/*
* console_unblank can no longer be called in interrupt context unless
* oops_in_progress is set to 1..
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 3e3d784..feffff1 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -135,7 +135,14 @@
spin_lock_irq(&task->sighand->siglock);
if (task_is_traced(task) && !__fatal_signal_pending(task)) {
- task->state = __TASK_TRACED;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+ if (task->state & __TASK_TRACED)
+ task->state = __TASK_TRACED;
+ else
+ task->saved_state = __TASK_TRACED;
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
ret = true;
}
spin_unlock_irq(&task->sighand->siglock);
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index b02a339..7e1dd3e 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -129,6 +129,7 @@
}
EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled);
+#ifndef CONFIG_PREEMPT_RT_FULL
/**
* rcu_read_lock_bh_held() - might we be in RCU-bh read-side critical section?
*
@@ -155,6 +156,7 @@
return in_softirq() || irqs_disabled();
}
EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);
+#endif
#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index c64d0ba..25884c3 100644
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -374,6 +374,7 @@
}
EXPORT_SYMBOL_GPL(call_rcu_sched);
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* Post an RCU bottom-half callback to be invoked after any subsequent
* quiescent state.
@@ -383,6 +384,7 @@
__call_rcu(head, func, &rcu_bh_ctrlblk);
}
EXPORT_SYMBOL_GPL(call_rcu_bh);
+#endif
void rcu_init(void)
{
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index be63101..a31bab6 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -473,6 +473,7 @@
.name = "rcu"
};
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* Definitions for rcu_bh torture testing.
*/
@@ -515,6 +516,12 @@
.name = "rcu_bh"
};
+#else
+static struct rcu_torture_ops rcu_bh_ops = {
+ .ttype = INVALID_RCU_FLAVOR,
+};
+#endif
+
/*
* Definitions for srcu torture testing.
*/
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index a92bd6b..2c230f0 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -55,6 +55,11 @@
#include <linux/random.h>
#include <linux/ftrace_event.h>
#include <linux/suspend.h>
+#include <linux/delay.h>
+#include <linux/gfp.h>
+#include <linux/oom.h>
+#include <linux/smpboot.h>
+#include "time/tick-internal.h"
#include "rcutree.h"
#include <trace/events/rcu.h>
@@ -145,8 +150,6 @@
*/
static int rcu_scheduler_fully_active __read_mostly;
-#ifdef CONFIG_RCU_BOOST
-
/*
* Control variables for per-CPU and per-rcu_node kthreads. These
* handle all flavors of RCU.
@@ -156,8 +159,6 @@
DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
DEFINE_PER_CPU(char, rcu_cpu_has_work);
-#endif /* #ifdef CONFIG_RCU_BOOST */
-
static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu);
static void invoke_rcu_core(void);
static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp);
@@ -199,6 +200,19 @@
rdp->passed_quiesce = 1;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void rcu_preempt_qs(int cpu);
+
+void rcu_bh_qs(int cpu)
+{
+ unsigned long flags;
+
+ /* Callers to this function, rcu_preempt_qs(), must disable irqs. */
+ local_irq_save(flags);
+ rcu_preempt_qs(cpu);
+ local_irq_restore(flags);
+}
+#else
void rcu_bh_qs(int cpu)
{
struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu);
@@ -207,6 +221,7 @@
trace_rcu_grace_period(TPS("rcu_bh"), rdp->gpnum, TPS("cpuqs"));
rdp->passed_quiesce = 1;
}
+#endif
/*
* Note a context switch. This is a quiescent state for RCU-sched,
@@ -263,6 +278,7 @@
}
EXPORT_SYMBOL_GPL(rcu_batches_completed_sched);
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* Return the number of RCU BH batches processed thus far for debug & stats.
*/
@@ -280,6 +296,7 @@
force_quiescent_state(&rcu_bh_state);
}
EXPORT_SYMBOL_GPL(rcu_bh_force_quiescent_state);
+#endif
/*
* Record the number of times rcutorture tests have been initiated and
@@ -1177,7 +1194,7 @@
!ACCESS_ONCE(rsp->gp_flags) ||
!rsp->gp_kthread)
return;
- wake_up(&rsp->gp_wq);
+ swait_wake(&rsp->gp_wq);
}
/*
@@ -1522,7 +1539,7 @@
/* Handle grace-period start. */
for (;;) {
- wait_event_interruptible(rsp->gp_wq,
+ swait_event_interruptible(rsp->gp_wq,
rsp->gp_flags &
RCU_GP_FLAG_INIT);
if ((rsp->gp_flags & RCU_GP_FLAG_INIT) &&
@@ -1541,7 +1558,7 @@
}
for (;;) {
rsp->jiffies_force_qs = jiffies + j;
- ret = wait_event_interruptible_timeout(rsp->gp_wq,
+ ret = swait_event_interruptible_timeout(rsp->gp_wq,
(rsp->gp_flags & RCU_GP_FLAG_FQS) ||
(!ACCESS_ONCE(rnp->qsmask) &&
!rcu_preempt_blocked_readers_cgp(rnp)),
@@ -2260,16 +2277,14 @@
/*
* Do RCU core processing for the current CPU.
*/
-static void rcu_process_callbacks(struct softirq_action *unused)
+static void rcu_process_callbacks(void)
{
struct rcu_state *rsp;
if (cpu_is_offline(smp_processor_id()))
return;
- trace_rcu_utilization(TPS("Start RCU core"));
for_each_rcu_flavor(rsp)
__rcu_process_callbacks(rsp);
- trace_rcu_utilization(TPS("End RCU core"));
}
/*
@@ -2283,19 +2298,106 @@
{
if (unlikely(!ACCESS_ONCE(rcu_scheduler_fully_active)))
return;
- if (likely(!rsp->boost)) {
- rcu_do_batch(rsp, rdp);
- return;
- }
- invoke_rcu_callbacks_kthread();
+ rcu_do_batch(rsp, rdp);
}
+static void rcu_wake_cond(struct task_struct *t, int status)
+{
+ /*
+ * If the thread is yielding, only wake it when this
+ * is invoked from idle
+ */
+ if (t && (status != RCU_KTHREAD_YIELDING || is_idle_task(current)))
+ wake_up_process(t);
+}
+
+/*
+ * Wake up this CPU's rcuc kthread to do RCU core processing.
+ */
static void invoke_rcu_core(void)
{
- if (cpu_online(smp_processor_id()))
- raise_softirq(RCU_SOFTIRQ);
+ unsigned long flags;
+ struct task_struct *t;
+
+ if (!cpu_online(smp_processor_id()))
+ return;
+ local_irq_save(flags);
+ __this_cpu_write(rcu_cpu_has_work, 1);
+ t = __this_cpu_read(rcu_cpu_kthread_task);
+ if (t != NULL && current != t)
+ rcu_wake_cond(t, __this_cpu_read(rcu_cpu_kthread_status));
+ local_irq_restore(flags);
}
+static void rcu_cpu_kthread_park(unsigned int cpu)
+{
+ per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU;
+}
+
+static int rcu_cpu_kthread_should_run(unsigned int cpu)
+{
+ return __this_cpu_read(rcu_cpu_has_work);
+}
+
+/*
+ * Per-CPU kernel thread that invokes RCU callbacks. This replaces the
+ * RCU softirq used in flavors and configurations of RCU that do not
+ * support RCU priority boosting.
+ */
+static void rcu_cpu_kthread(unsigned int cpu)
+{
+ unsigned int *statusp = &__get_cpu_var(rcu_cpu_kthread_status);
+ char work, *workp = &__get_cpu_var(rcu_cpu_has_work);
+ int spincnt;
+
+ for (spincnt = 0; spincnt < 10; spincnt++) {
+ trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait"));
+ local_bh_disable();
+ *statusp = RCU_KTHREAD_RUNNING;
+ this_cpu_inc(rcu_cpu_kthread_loops);
+ local_irq_disable();
+ work = *workp;
+ *workp = 0;
+ local_irq_enable();
+ if (work)
+ rcu_process_callbacks();
+ local_bh_enable();
+ if (*workp == 0) {
+ trace_rcu_utilization(TPS("End CPU kthread@rcu_wait"));
+ *statusp = RCU_KTHREAD_WAITING;
+ return;
+ }
+ }
+ *statusp = RCU_KTHREAD_YIELDING;
+ trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield"));
+ schedule_timeout_interruptible(2);
+ trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
+ *statusp = RCU_KTHREAD_WAITING;
+}
+
+static struct smp_hotplug_thread rcu_cpu_thread_spec = {
+ .store = &rcu_cpu_kthread_task,
+ .thread_should_run = rcu_cpu_kthread_should_run,
+ .thread_fn = rcu_cpu_kthread,
+ .thread_comm = "rcuc/%u",
+ .setup = rcu_cpu_kthread_setup,
+ .park = rcu_cpu_kthread_park,
+};
+
+/*
+ * Spawn per-CPU RCU core processing kthreads.
+ */
+static int __init rcu_spawn_core_kthreads(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ per_cpu(rcu_cpu_has_work, cpu) = 0;
+ BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec));
+ return 0;
+}
+early_initcall(rcu_spawn_core_kthreads);
+
/*
* Handle any core-RCU processing required by a call_rcu() invocation.
*/
@@ -2424,6 +2526,7 @@
}
EXPORT_SYMBOL_GPL(call_rcu_sched);
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* Queue an RCU callback for invocation after a quicker grace period.
*/
@@ -2432,6 +2535,7 @@
__call_rcu(head, func, &rcu_bh_state, -1, 0);
}
EXPORT_SYMBOL_GPL(call_rcu_bh);
+#endif
/*
* Because a context switch is a grace period for RCU-sched and RCU-bh,
@@ -2509,6 +2613,7 @@
}
EXPORT_SYMBOL_GPL(synchronize_sched);
+#ifndef CONFIG_PREEMPT_RT_FULL
/**
* synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed.
*
@@ -2535,6 +2640,7 @@
wait_rcu_gp(call_rcu_bh);
}
EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
+#endif
static int synchronize_sched_expedited_cpu_stop(void *data)
{
@@ -2709,6 +2815,10 @@
/* Check for CPU stalls, if enabled. */
check_cpu_stall(rsp, rdp);
+ /* Is this CPU a NO_HZ_FULL CPU that should ignore RCU? */
+ if (rcu_nohz_full_cpu(rsp))
+ return 0;
+
/* Is the RCU core waiting for a quiescent state from this CPU? */
if (rcu_scheduler_fully_active &&
rdp->qs_pending && !rdp->passed_quiesce) {
@@ -2942,6 +3052,7 @@
mutex_unlock(&rsp->barrier_mutex);
}
+#ifndef CONFIG_PREEMPT_RT_FULL
/**
* rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
*/
@@ -2950,6 +3061,7 @@
_rcu_barrier(&rcu_bh_state);
}
EXPORT_SYMBOL_GPL(rcu_barrier_bh);
+#endif
/**
* rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks.
@@ -3253,7 +3365,7 @@
}
rsp->rda = rda;
- init_waitqueue_head(&rsp->gp_wq);
+ init_swait_head(&rsp->gp_wq);
init_irq_work(&rsp->wakeup_work, rsp_wakeup);
rnp = rsp->level[rcu_num_lvls - 1];
for_each_possible_cpu(i) {
@@ -3349,7 +3461,6 @@
rcu_init_one(&rcu_sched_state, &rcu_sched_data);
rcu_init_one(&rcu_bh_state, &rcu_bh_data);
__rcu_init_preempt();
- open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
/*
* We don't need protection against CPU-hotplug here because
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 52be957..1df8d9e 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -28,6 +28,7 @@
#include <linux/cpumask.h>
#include <linux/seqlock.h>
#include <linux/irq_work.h>
+#include <linux/wait-simple.h>
/*
* Define shape of hierarchy based on NR_CPUS, CONFIG_RCU_FANOUT, and
@@ -200,7 +201,7 @@
/* This can happen due to race conditions. */
#endif /* #ifdef CONFIG_RCU_BOOST */
#ifdef CONFIG_RCU_NOCB_CPU
- wait_queue_head_t nocb_gp_wq[2];
+ struct swait_head nocb_gp_wq[2];
/* Place for rcu_nocb_kthread() to wait GP. */
#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
int need_future_gp[2];
@@ -333,7 +334,7 @@
atomic_long_t nocb_q_count_lazy; /* (approximate). */
int nocb_p_count; /* # CBs being invoked by kthread */
int nocb_p_count_lazy; /* (approximate). */
- wait_queue_head_t nocb_wq; /* For nocb kthreads to sleep on. */
+ struct swait_head nocb_wq; /* For nocb kthreads to sleep on. */
struct task_struct *nocb_kthread;
#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
@@ -403,7 +404,7 @@
unsigned long gpnum; /* Current gp number. */
unsigned long completed; /* # of last completed gp. */
struct task_struct *gp_kthread; /* Task for grace periods. */
- wait_queue_head_t gp_wq; /* Where GP task waits. */
+ struct swait_head gp_wq; /* Where GP task waits. */
int gp_flags; /* Commands for GP task. */
/* End of fields guarded by root rcu_node's lock. */
@@ -527,10 +528,9 @@
static void __init __rcu_init_preempt(void);
static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags);
static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
-static void invoke_rcu_callbacks_kthread(void);
static bool rcu_is_callbacks_kthread(void);
+static void rcu_cpu_kthread_setup(unsigned int cpu);
#ifdef CONFIG_RCU_BOOST
-static void rcu_preempt_do_callbacks(void);
static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
struct rcu_node *rnp);
#endif /* #ifdef CONFIG_RCU_BOOST */
@@ -564,6 +564,7 @@
unsigned long maxj);
static void rcu_bind_gp_kthread(void);
static void rcu_sysidle_init_percpu_data(struct rcu_dynticks *rdtp);
+static bool rcu_nohz_full_cpu(struct rcu_state *rsp);
#endif /* #ifndef RCU_TREE_NONCORE */
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index a55fec5..c50a720 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -24,12 +24,6 @@
* Paul E. McKenney <paulmck@linux.vnet.ibm.com>
*/
-#include <linux/delay.h>
-#include <linux/gfp.h>
-#include <linux/oom.h>
-#include <linux/smpboot.h>
-#include "time/tick-internal.h"
-
#define RCU_KTHREAD_PRIO 1
#ifdef CONFIG_RCU_BOOST
@@ -359,7 +353,7 @@
}
/* Hardware IRQ handlers cannot block. */
- if (in_irq() || in_serving_softirq()) {
+ if (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_OFFSET)) {
local_irq_restore(flags);
return;
}
@@ -656,15 +650,6 @@
t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS;
}
-#ifdef CONFIG_RCU_BOOST
-
-static void rcu_preempt_do_callbacks(void)
-{
- rcu_do_batch(&rcu_preempt_state, &__get_cpu_var(rcu_preempt_data));
-}
-
-#endif /* #ifdef CONFIG_RCU_BOOST */
-
/*
* Queue a preemptible-RCU callback for invocation after a grace period.
*/
@@ -1126,6 +1111,19 @@
#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
+/*
+ * If boosting, set rcuc kthreads to realtime priority.
+ */
+static void rcu_cpu_kthread_setup(unsigned int cpu)
+{
+#ifdef CONFIG_RCU_BOOST
+ struct sched_param sp;
+
+ sp.sched_priority = RCU_KTHREAD_PRIO;
+ sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
+#endif /* #ifdef CONFIG_RCU_BOOST */
+}
+
#ifdef CONFIG_RCU_BOOST
#include "rtmutex_common.h"
@@ -1157,16 +1155,6 @@
#endif /* #else #ifdef CONFIG_RCU_TRACE */
-static void rcu_wake_cond(struct task_struct *t, int status)
-{
- /*
- * If the thread is yielding, only wake it when this
- * is invoked from idle
- */
- if (status != RCU_KTHREAD_YIELDING || is_idle_task(current))
- wake_up_process(t);
-}
-
/*
* Carry out RCU priority boosting on the task indicated by ->exp_tasks
* or ->boost_tasks, advancing the pointer to the next task in the
@@ -1310,23 +1298,6 @@
}
/*
- * Wake up the per-CPU kthread to invoke RCU callbacks.
- */
-static void invoke_rcu_callbacks_kthread(void)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- __this_cpu_write(rcu_cpu_has_work, 1);
- if (__this_cpu_read(rcu_cpu_kthread_task) != NULL &&
- current != __this_cpu_read(rcu_cpu_kthread_task)) {
- rcu_wake_cond(__this_cpu_read(rcu_cpu_kthread_task),
- __this_cpu_read(rcu_cpu_kthread_status));
- }
- local_irq_restore(flags);
-}
-
-/*
* Is the current CPU running the RCU-callbacks kthread?
* Caller must have preemption disabled.
*/
@@ -1380,67 +1351,6 @@
return 0;
}
-static void rcu_kthread_do_work(void)
-{
- rcu_do_batch(&rcu_sched_state, &__get_cpu_var(rcu_sched_data));
- rcu_do_batch(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
- rcu_preempt_do_callbacks();
-}
-
-static void rcu_cpu_kthread_setup(unsigned int cpu)
-{
- struct sched_param sp;
-
- sp.sched_priority = RCU_KTHREAD_PRIO;
- sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
-}
-
-static void rcu_cpu_kthread_park(unsigned int cpu)
-{
- per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU;
-}
-
-static int rcu_cpu_kthread_should_run(unsigned int cpu)
-{
- return __get_cpu_var(rcu_cpu_has_work);
-}
-
-/*
- * Per-CPU kernel thread that invokes RCU callbacks. This replaces the
- * RCU softirq used in flavors and configurations of RCU that do not
- * support RCU priority boosting.
- */
-static void rcu_cpu_kthread(unsigned int cpu)
-{
- unsigned int *statusp = &__get_cpu_var(rcu_cpu_kthread_status);
- char work, *workp = &__get_cpu_var(rcu_cpu_has_work);
- int spincnt;
-
- for (spincnt = 0; spincnt < 10; spincnt++) {
- trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait"));
- local_bh_disable();
- *statusp = RCU_KTHREAD_RUNNING;
- this_cpu_inc(rcu_cpu_kthread_loops);
- local_irq_disable();
- work = *workp;
- *workp = 0;
- local_irq_enable();
- if (work)
- rcu_kthread_do_work();
- local_bh_enable();
- if (*workp == 0) {
- trace_rcu_utilization(TPS("End CPU kthread@rcu_wait"));
- *statusp = RCU_KTHREAD_WAITING;
- return;
- }
- }
- *statusp = RCU_KTHREAD_YIELDING;
- trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield"));
- schedule_timeout_interruptible(2);
- trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
- *statusp = RCU_KTHREAD_WAITING;
-}
-
/*
* Set the per-rcu_node kthread's affinity to cover all CPUs that are
* served by the rcu_node in question. The CPU hotplug lock is still
@@ -1474,27 +1384,14 @@
free_cpumask_var(cm);
}
-static struct smp_hotplug_thread rcu_cpu_thread_spec = {
- .store = &rcu_cpu_kthread_task,
- .thread_should_run = rcu_cpu_kthread_should_run,
- .thread_fn = rcu_cpu_kthread,
- .thread_comm = "rcuc/%u",
- .setup = rcu_cpu_kthread_setup,
- .park = rcu_cpu_kthread_park,
-};
-
/*
* Spawn all kthreads -- called as soon as the scheduler is running.
*/
static int __init rcu_spawn_kthreads(void)
{
struct rcu_node *rnp;
- int cpu;
rcu_scheduler_fully_active = 1;
- for_each_possible_cpu(cpu)
- per_cpu(rcu_cpu_has_work, cpu) = 0;
- BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec));
rnp = rcu_get_root(rcu_state);
(void)rcu_spawn_one_boost_kthread(rcu_state, rnp);
if (NUM_RCU_NODES > 1) {
@@ -1522,11 +1419,6 @@
raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
-static void invoke_rcu_callbacks_kthread(void)
-{
- WARN_ON_ONCE(1);
-}
-
static bool rcu_is_callbacks_kthread(void)
{
return false;
@@ -1553,7 +1445,7 @@
#endif /* #else #ifdef CONFIG_RCU_BOOST */
-#if !defined(CONFIG_RCU_FAST_NO_HZ)
+#if !defined(CONFIG_RCU_FAST_NO_HZ) || defined(CONFIG_PREEMPT_RT_FULL)
/*
* Check to see if any future RCU-related work will need to be done
@@ -1569,6 +1461,9 @@
*delta_jiffies = ULONG_MAX;
return rcu_cpu_has_callbacks(cpu, NULL);
}
+#endif /* !defined(CONFIG_RCU_FAST_NO_HZ) || defined(CONFIG_PREEMPT_RT_FULL) */
+
+#if !defined(CONFIG_RCU_FAST_NO_HZ)
/*
* Because we do not have RCU_FAST_NO_HZ, don't bother cleaning up
@@ -1666,6 +1561,8 @@
return cbs_ready;
}
+#ifndef CONFIG_PREEMPT_RT_FULL
+
/*
* Allow the CPU to enter dyntick-idle mode unless it has callbacks ready
* to invoke. If the CPU has callbacks, try to advance them. Tell the
@@ -1704,6 +1601,7 @@
}
return 0;
}
+#endif /* #ifndef CONFIG_PREEMPT_RT_FULL */
/*
* Prepare a CPU for idle from an RCU perspective. The first major task
@@ -2061,7 +1959,7 @@
*/
static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp)
{
- wake_up_all(&rnp->nocb_gp_wq[rnp->completed & 0x1]);
+ swait_wake_all(&rnp->nocb_gp_wq[rnp->completed & 0x1]);
}
/*
@@ -2079,8 +1977,8 @@
static void rcu_init_one_nocb(struct rcu_node *rnp)
{
- init_waitqueue_head(&rnp->nocb_gp_wq[0]);
- init_waitqueue_head(&rnp->nocb_gp_wq[1]);
+ init_swait_head(&rnp->nocb_gp_wq[0]);
+ init_swait_head(&rnp->nocb_gp_wq[1]);
}
/* Is the specified CPU a no-CPUs CPU? */
@@ -2120,7 +2018,7 @@
return;
len = atomic_long_read(&rdp->nocb_q_count);
if (old_rhpp == &rdp->nocb_head) {
- wake_up(&rdp->nocb_wq); /* ... only if queue was empty ... */
+ swait_wake(&rdp->nocb_wq); /* ... only if queue was empty ... */
rdp->qlen_last_fqs_check = 0;
} else if (len > rdp->qlen_last_fqs_check + qhimark) {
wake_up_process(t); /* ... or if many callbacks queued. */
@@ -2210,7 +2108,7 @@
*/
trace_rcu_future_gp(rnp, rdp, c, TPS("StartWait"));
for (;;) {
- wait_event_interruptible(
+ swait_event_interruptible(
rnp->nocb_gp_wq[c & 0x1],
(d = ULONG_CMP_GE(ACCESS_ONCE(rnp->completed), c)));
if (likely(d))
@@ -2238,7 +2136,7 @@
for (;;) {
/* If not polling, wait for next batch of callbacks. */
if (!rcu_nocb_poll)
- wait_event_interruptible(rdp->nocb_wq, rdp->nocb_head);
+ swait_event_interruptible(rdp->nocb_wq, rdp->nocb_head);
list = ACCESS_ONCE(rdp->nocb_head);
if (!list) {
schedule_timeout_interruptible(1);
@@ -2289,7 +2187,7 @@
static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp)
{
rdp->nocb_tail = &rdp->nocb_head;
- init_waitqueue_head(&rdp->nocb_wq);
+ init_swait_head(&rdp->nocb_wq);
}
/* Create a kthread for each RCU flavor for each no-CBs CPU. */
@@ -2804,3 +2702,23 @@
}
#endif /* #else #ifdef CONFIG_NO_HZ_FULL_SYSIDLE */
+
+/*
+ * Is this CPU a NO_HZ_FULL CPU that should ignore RCU so that the
+ * grace-period kthread will do force_quiescent_state() processing?
+ * The idea is to avoid waking up RCU core processing on such a
+ * CPU unless the grace period has extended for too long.
+ *
+ * This code relies on the fact that all NO_HZ_FULL CPUs are also
+ * CONFIG_RCU_NOCB_CPUs.
+ */
+static bool rcu_nohz_full_cpu(struct rcu_state *rsp)
+{
+#ifdef CONFIG_NO_HZ_FULL
+ if (tick_nohz_full_cpu(smp_processor_id()) &&
+ (!rcu_gp_in_progress(rsp) ||
+ ULONG_CMP_LT(jiffies, ACCESS_ONCE(rsp->gp_start) + HZ)))
+ return 1;
+#endif /* #ifdef CONFIG_NO_HZ_FULL */
+ return 0;
+}
diff --git a/kernel/relay.c b/kernel/relay.c
index 5001c98..b915513 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -339,6 +339,10 @@
{
struct rchan_buf *buf = (struct rchan_buf *)data;
wake_up_interruptible(&buf->read_wait);
+ /*
+ * Stupid polling for now:
+ */
+ mod_timer(&buf->timer, jiffies + 1);
}
/**
@@ -356,6 +360,7 @@
init_waitqueue_head(&buf->read_wait);
kref_init(&buf->kref);
setup_timer(&buf->timer, wakeup_readers, (unsigned long)buf);
+ mod_timer(&buf->timer, jiffies + 1);
} else
del_timer_sync(&buf->timer);
@@ -739,15 +744,6 @@
else
buf->early_bytes += buf->chan->subbuf_size -
buf->padding[old_subbuf];
- smp_mb();
- if (waitqueue_active(&buf->read_wait))
- /*
- * Calling wake_up_interruptible() from here
- * will deadlock if we happen to be logging
- * from the scheduler (trying to re-grab
- * rq->lock), so defer it.
- */
- mod_timer(&buf->timer, jiffies + 1);
}
old = buf->data;
diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index 4aa8a30..3fbcb0d 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -49,7 +49,7 @@
r = ret = 0;
*limit_fail_at = NULL;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
for (c = counter; c != NULL; c = c->parent) {
spin_lock(&c->lock);
r = res_counter_charge_locked(c, val, force);
@@ -69,7 +69,7 @@
spin_unlock(&u->lock);
}
}
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return ret;
}
@@ -103,7 +103,7 @@
struct res_counter *c;
u64 ret = 0;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
for (c = counter; c != top; c = c->parent) {
u64 r;
spin_lock(&c->lock);
@@ -112,7 +112,7 @@
ret = r;
spin_unlock(&c->lock);
}
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return ret;
}
diff --git a/kernel/rt.c b/kernel/rt.c
new file mode 100644
index 0000000..b31716c
--- /dev/null
+++ b/kernel/rt.c
@@ -0,0 +1,456 @@
+/*
+ * kernel/rt.c
+ *
+ * Real-Time Preemption Support
+ *
+ * started by Ingo Molnar:
+ *
+ * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ * historic credit for proving that Linux spinlocks can be implemented via
+ * RT-aware mutexes goes to many people: The Pmutex project (Dirk Grambow
+ * and others) who prototyped it on 2.4 and did lots of comparative
+ * research and analysis; TimeSys, for proving that you can implement a
+ * fully preemptible kernel via the use of IRQ threading and mutexes;
+ * Bill Huey for persuasively arguing on lkml that the mutex model is the
+ * right one; and to MontaVista, who ported pmutexes to 2.6.
+ *
+ * This code is a from-scratch implementation and is not based on pmutexes,
+ * but the idea of converting spinlocks to mutexes is used here too.
+ *
+ * lock debugging, locking tree, deadlock detection:
+ *
+ * Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
+ * Released under the General Public License (GPL).
+ *
+ * Includes portions of the generic R/W semaphore implementation from:
+ *
+ * Copyright (c) 2001 David Howells (dhowells@redhat.com).
+ * - Derived partially from idea by Andrea Arcangeli <andrea@suse.de>
+ * - Derived also from comments by Linus
+ *
+ * Pending ownership of locks and ownership stealing:
+ *
+ * Copyright (C) 2005, Kihon Technologies Inc., Steven Rostedt
+ *
+ * (also by Steven Rostedt)
+ * - Converted single pi_lock to individual task locks.
+ *
+ * By Esben Nielsen:
+ * Doing priority inheritance with help of the scheduler.
+ *
+ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ * - major rework based on Esben Nielsens initial patch
+ * - replaced thread_info references by task_struct refs
+ * - removed task->pending_owner dependency
+ * - BKL drop/reacquire for semaphore style locks to avoid deadlocks
+ * in the scheduler return path as discussed with Steven Rostedt
+ *
+ * Copyright (C) 2006, Kihon Technologies Inc.
+ * Steven Rostedt <rostedt@goodmis.org>
+ * - debugged and patched Thomas Gleixner's rework.
+ * - added back the cmpxchg to the rework.
+ * - turned atomic require back on for SMP.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/rtmutex.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/syscalls.h>
+#include <linux/interrupt.h>
+#include <linux/plist.h>
+#include <linux/fs.h>
+#include <linux/futex.h>
+#include <linux/hrtimer.h>
+
+#include "rtmutex_common.h"
+
+/*
+ * struct mutex functions
+ */
+void __mutex_do_init(struct mutex *mutex, const char *name,
+ struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)mutex, sizeof(*mutex));
+ lockdep_init_map(&mutex->dep_map, name, key, 0);
+#endif
+ mutex->lock.save_state = 0;
+}
+EXPORT_SYMBOL(__mutex_do_init);
+
+void __lockfunc _mutex_lock(struct mutex *lock)
+{
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock);
+
+int __lockfunc _mutex_lock_interruptible(struct mutex *lock)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ ret = rt_mutex_lock_interruptible(&lock->lock);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible);
+
+int __lockfunc _mutex_lock_killable(struct mutex *lock)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ ret = rt_mutex_lock_killable(&lock->lock);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass)
+{
+ mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+ rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock_nested);
+
+void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
+{
+ mutex_acquire_nest(&lock->dep_map, 0, 0, nest, _RET_IP_);
+ rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock_nest_lock);
+
+int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass)
+{
+ int ret;
+
+ mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+ ret = rt_mutex_lock_interruptible(&lock->lock);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible_nested);
+
+int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+ ret = rt_mutex_lock_killable(&lock->lock);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable_nested);
+#endif
+
+int __lockfunc _mutex_trylock(struct mutex *lock)
+{
+ int ret = rt_mutex_trylock(&lock->lock);
+
+ if (ret)
+ mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+
+ return ret;
+}
+EXPORT_SYMBOL(_mutex_trylock);
+
+void __lockfunc _mutex_unlock(struct mutex *lock)
+{
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ rt_mutex_unlock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_unlock);
+
+/*
+ * rwlock_t functions
+ */
+int __lockfunc rt_write_trylock(rwlock_t *rwlock)
+{
+ int ret;
+
+ migrate_disable();
+ ret = rt_mutex_trylock(&rwlock->lock);
+
+ if (ret)
+ rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
+ else
+ migrate_enable();
+
+ return ret;
+}
+EXPORT_SYMBOL(rt_write_trylock);
+
+int __lockfunc rt_write_trylock_irqsave(rwlock_t *rwlock, unsigned long *flags)
+{
+ int ret;
+
+ *flags = 0;
+ ret = rt_write_trylock(rwlock);
+ return ret;
+}
+EXPORT_SYMBOL(rt_write_trylock_irqsave);
+
+int __lockfunc rt_read_trylock(rwlock_t *rwlock)
+{
+ struct rt_mutex *lock = &rwlock->lock;
+ int ret = 1;
+
+ /*
+ * recursive read locks succeed when current owns the lock,
+ * but not when read_depth == 0 which means that the lock is
+ * write locked.
+ */
+ if (rt_mutex_owner(lock) != current) {
+ migrate_disable();
+ ret = rt_mutex_trylock(lock);
+ if (ret)
+ rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
+ else
+ migrate_enable();
+ } else if (!rwlock->read_depth) {
+ ret = 0;
+ }
+
+ if (ret)
+ rwlock->read_depth++;
+
+ return ret;
+}
+EXPORT_SYMBOL(rt_read_trylock);
+
+void __lockfunc rt_write_lock(rwlock_t *rwlock)
+{
+ rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
+ migrate_disable();
+ __rt_spin_lock(&rwlock->lock);
+}
+EXPORT_SYMBOL(rt_write_lock);
+
+void __lockfunc rt_read_lock(rwlock_t *rwlock)
+{
+ struct rt_mutex *lock = &rwlock->lock;
+
+ /*
+ * recursive read locks succeed when current owns the lock
+ */
+ if (rt_mutex_owner(lock) != current) {
+ rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
+ migrate_disable();
+ __rt_spin_lock(lock);
+ }
+ rwlock->read_depth++;
+}
+
+EXPORT_SYMBOL(rt_read_lock);
+
+void __lockfunc rt_write_unlock(rwlock_t *rwlock)
+{
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
+ __rt_spin_unlock(&rwlock->lock);
+ migrate_enable();
+}
+EXPORT_SYMBOL(rt_write_unlock);
+
+void __lockfunc rt_read_unlock(rwlock_t *rwlock)
+{
+ /* Release the lock only when read_depth is down to 0 */
+ if (--rwlock->read_depth == 0) {
+ rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
+ __rt_spin_unlock(&rwlock->lock);
+ migrate_enable();
+ }
+}
+EXPORT_SYMBOL(rt_read_unlock);
+
+unsigned long __lockfunc rt_write_lock_irqsave(rwlock_t *rwlock)
+{
+ rt_write_lock(rwlock);
+
+ return 0;
+}
+EXPORT_SYMBOL(rt_write_lock_irqsave);
+
+unsigned long __lockfunc rt_read_lock_irqsave(rwlock_t *rwlock)
+{
+ rt_read_lock(rwlock);
+
+ return 0;
+}
+EXPORT_SYMBOL(rt_read_lock_irqsave);
+
+void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)rwlock, sizeof(*rwlock));
+ lockdep_init_map(&rwlock->dep_map, name, key, 0);
+#endif
+ rwlock->lock.save_state = 1;
+ rwlock->read_depth = 0;
+}
+EXPORT_SYMBOL(__rt_rwlock_init);
+
+/*
+ * rw_semaphores
+ */
+
+void rt_up_write(struct rw_semaphore *rwsem)
+{
+ rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
+ rt_mutex_unlock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_up_write);
+
+void rt_up_read(struct rw_semaphore *rwsem)
+{
+ if (--rwsem->read_depth == 0) {
+ rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
+ rt_mutex_unlock(&rwsem->lock);
+ }
+}
+EXPORT_SYMBOL(rt_up_read);
+
+/*
+ * downgrade a write lock into a read lock
+ * - just wake up any readers at the front of the queue
+ */
+void rt_downgrade_write(struct rw_semaphore *rwsem)
+{
+ BUG_ON(rt_mutex_owner(&rwsem->lock) != current);
+ rwsem->read_depth = 1;
+}
+EXPORT_SYMBOL(rt_downgrade_write);
+
+int rt_down_write_trylock(struct rw_semaphore *rwsem)
+{
+ int ret = rt_mutex_trylock(&rwsem->lock);
+
+ if (ret)
+ rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(rt_down_write_trylock);
+
+void rt_down_write(struct rw_semaphore *rwsem)
+{
+ rwsem_acquire(&rwsem->dep_map, 0, 0, _RET_IP_);
+ rt_mutex_lock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_down_write);
+
+void rt_down_write_nested(struct rw_semaphore *rwsem, int subclass)
+{
+ rwsem_acquire(&rwsem->dep_map, subclass, 0, _RET_IP_);
+ rt_mutex_lock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_down_write_nested);
+
+void rt_down_write_nested_lock(struct rw_semaphore *rwsem,
+ struct lockdep_map *nest)
+{
+ rwsem_acquire_nest(&rwsem->dep_map, 0, 0, nest, _RET_IP_);
+ rt_mutex_lock(&rwsem->lock);
+}
+
+int rt_down_read_trylock(struct rw_semaphore *rwsem)
+{
+ struct rt_mutex *lock = &rwsem->lock;
+ int ret = 1;
+
+ /*
+ * recursive read locks succeed when current owns the rwsem,
+ * but not when read_depth == 0 which means that the rwsem is
+ * write locked.
+ */
+ if (rt_mutex_owner(lock) != current) {
+ ret = rt_mutex_trylock(&rwsem->lock);
+ if (ret)
+ rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
+ } else if (!rwsem->read_depth) {
+ ret = 0;
+ }
+
+ if (ret)
+ rwsem->read_depth++;
+ return ret;
+}
+EXPORT_SYMBOL(rt_down_read_trylock);
+
+static void __rt_down_read(struct rw_semaphore *rwsem, int subclass)
+{
+ struct rt_mutex *lock = &rwsem->lock;
+
+ if (rt_mutex_owner(lock) != current) {
+ rwsem_acquire(&rwsem->dep_map, subclass, 0, _RET_IP_);
+ rt_mutex_lock(&rwsem->lock);
+ }
+ rwsem->read_depth++;
+}
+
+void rt_down_read(struct rw_semaphore *rwsem)
+{
+ __rt_down_read(rwsem, 0);
+}
+EXPORT_SYMBOL(rt_down_read);
+
+void rt_down_read_nested(struct rw_semaphore *rwsem, int subclass)
+{
+ __rt_down_read(rwsem, subclass);
+}
+EXPORT_SYMBOL(rt_down_read_nested);
+
+void __rt_rwsem_init(struct rw_semaphore *rwsem, const char *name,
+ struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)rwsem, sizeof(*rwsem));
+ lockdep_init_map(&rwsem->dep_map, name, key, 0);
+#endif
+ rwsem->read_depth = 0;
+ rwsem->lock.save_state = 0;
+}
+EXPORT_SYMBOL(__rt_rwsem_init);
+
+/**
+ * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
+ * @cnt: the atomic which we are to dec
+ * @lock: the mutex to return holding if we dec to 0
+ *
+ * return true and hold lock if we dec to 0, return false otherwise
+ */
+int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
+{
+ /* dec if we can't possibly hit 0 */
+ if (atomic_add_unless(cnt, -1, 1))
+ return 0;
+ /* we might hit 0, so take the lock */
+ mutex_lock(lock);
+ if (!atomic_dec_and_test(cnt)) {
+ /* when we actually did the dec, we didn't hit 0 */
+ mutex_unlock(lock);
+ return 0;
+ }
+ /* we hit 0, and we hold the lock */
+ return 1;
+}
+EXPORT_SYMBOL(atomic_dec_and_mutex_lock);
diff --git a/kernel/rtmutex-debug.c b/kernel/rtmutex-debug.c
index 13b243a..2035a46 100644
--- a/kernel/rtmutex-debug.c
+++ b/kernel/rtmutex-debug.c
@@ -66,12 +66,13 @@
* the deadlock. We print when we return. act_waiter can be NULL in
* case of a remove waiter operation.
*/
-void debug_rt_mutex_deadlock(int detect, struct rt_mutex_waiter *act_waiter,
+void debug_rt_mutex_deadlock(enum rtmutex_chainwalk chwalk,
+ struct rt_mutex_waiter *act_waiter,
struct rt_mutex *lock)
{
struct task_struct *task;
- if (!debug_locks || detect || !act_waiter)
+ if (!debug_locks || chwalk == RT_MUTEX_FULL_CHAINWALK || !act_waiter)
return;
task = rt_mutex_owner(act_waiter->lock);
diff --git a/kernel/rtmutex-debug.h b/kernel/rtmutex-debug.h
index ab29b6a..d0519c3 100644
--- a/kernel/rtmutex-debug.h
+++ b/kernel/rtmutex-debug.h
@@ -20,14 +20,15 @@
extern void debug_rt_mutex_proxy_lock(struct rt_mutex *lock,
struct task_struct *powner);
extern void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock);
-extern void debug_rt_mutex_deadlock(int detect, struct rt_mutex_waiter *waiter,
+extern void debug_rt_mutex_deadlock(enum rtmutex_chainwalk chwalk,
+ struct rt_mutex_waiter *waiter,
struct rt_mutex *lock);
extern void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter);
# define debug_rt_mutex_reset_waiter(w) \
do { (w)->deadlock_lock = NULL; } while (0)
-static inline int debug_rt_mutex_detect_deadlock(struct rt_mutex_waiter *waiter,
- int detect)
+static inline bool debug_rt_mutex_detect_deadlock(struct rt_mutex_waiter *waiter,
+ enum rtmutex_chainwalk walk)
{
return (waiter != NULL);
}
diff --git a/kernel/rtmutex-tester.c b/kernel/rtmutex-tester.c
index 1d96dd0..a6b605b 100644
--- a/kernel/rtmutex-tester.c
+++ b/kernel/rtmutex-tester.c
@@ -16,7 +16,7 @@
#include <linux/freezer.h>
#include <linux/stat.h>
-#include "rtmutex.h"
+#include "rtmutex_common.h"
#define MAX_RT_TEST_THREADS 8
#define MAX_RT_TEST_MUTEXES 8
@@ -107,7 +107,7 @@
td->mutexes[id] = 1;
td->event = atomic_add_return(1, &rttest_event);
- ret = rt_mutex_lock_interruptible(&mutexes[id], 0);
+ ret = rt_mutex_lock_interruptible(&mutexes[id]);
td->event = atomic_add_return(1, &rttest_event);
td->mutexes[id] = ret ? 0 : 4;
return ret ? -EINTR : 0;
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 132c6a0..43d98d3 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -8,6 +8,12 @@
* Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt
* Copyright (C) 2006 Esben Nielsen
*
+ * Adaptive Spinlocks:
+ * Copyright (C) 2008 Novell, Inc., Gregory Haskins, Sven Dietrich,
+ * and Peter Morreale,
+ * Adaptive Spinlocks simplification:
+ * Copyright (C) 2008 Red Hat, Inc., Steven Rostedt <srostedt@redhat.com>
+ *
* See Documentation/rt-mutex-design.txt for details.
*/
#include <linux/spinlock.h>
@@ -15,6 +21,7 @@
#include <linux/sched.h>
#include <linux/sched/rt.h>
#include <linux/timer.h>
+#include <linux/ww_mutex.h>
#include "rtmutex_common.h"
@@ -132,6 +139,12 @@
WRITE_ONCE(*p, owner & ~RT_MUTEX_HAS_WAITERS);
}
+static int rt_mutex_real_waiter(struct rt_mutex_waiter *waiter)
+{
+ return waiter && waiter != PI_WAKEUP_INPROGRESS &&
+ waiter != PI_REQUEUE_INPROGRESS;
+}
+
/*
* We can speed up the acquire/release, if the architecture
* supports cmpxchg and if there's no debugging state to be set up
@@ -207,6 +220,37 @@
}
#endif
+static inline void
+rt_mutex_enqueue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter)
+{
+ plist_add(&waiter->list_entry, &lock->wait_list);
+}
+
+static inline void
+rt_mutex_dequeue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter)
+{
+ plist_del(&waiter->list_entry, &lock->wait_list);
+}
+
+static inline void
+rt_mutex_enqueue_pi(struct task_struct *task, struct rt_mutex_waiter *waiter)
+{
+ waiter->pi_list_entry.prio = waiter->list_entry.prio;
+ plist_add(&waiter->pi_list_entry, &task->pi_waiters);
+}
+
+static inline void
+rt_mutex_dequeue_pi(struct task_struct *task, struct rt_mutex_waiter *waiter)
+{
+ plist_del(&waiter->pi_list_entry, &task->pi_waiters);
+}
+
+static inline void init_lists(struct rt_mutex *lock)
+{
+ if (unlikely(!lock->wait_list.node_list.prev))
+ plist_head_init(&lock->wait_list);
+}
+
/*
* Calculate task priority from the waiter list priority
*
@@ -223,6 +267,18 @@
}
/*
+ * Called by sched_setscheduler() to check whether the priority change
+ * is overruled by a possible priority boosting.
+ */
+int rt_mutex_check_prio(struct task_struct *task, int newprio)
+{
+ if (!task_has_pi_waiters(task))
+ return 0;
+
+ return task_top_pi_waiter(task)->pi_list_entry.prio <= newprio;
+}
+
+/*
* Adjust the priority of a task, after its pi_waiters got modified.
*
* This can be both boosting and unboosting. task->pi_lock must be held.
@@ -253,6 +309,40 @@
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
}
+static void rt_mutex_wake_waiter(struct rt_mutex_waiter *waiter)
+{
+ if (waiter->savestate)
+ wake_up_lock_sleeper(waiter->task);
+ else
+ wake_up_process(waiter->task);
+}
+
+/*
+ * Deadlock detection is conditional:
+ *
+ * If CONFIG_DEBUG_RT_MUTEXES=n, deadlock detection is only conducted
+ * if the detect argument is == RT_MUTEX_FULL_CHAINWALK.
+ *
+ * If CONFIG_DEBUG_RT_MUTEXES=y, deadlock detection is always
+ * conducted independent of the detect argument.
+ *
+ * If the waiter argument is NULL this indicates the deboost path and
+ * deadlock detection is disabled independent of the detect argument
+ * and the config settings.
+ */
+static bool rt_mutex_cond_detect_deadlock(struct rt_mutex_waiter *waiter,
+ enum rtmutex_chainwalk chwalk)
+{
+ /*
+ * This is just a wrapper function for the following call,
+ * because debug_rt_mutex_detect_deadlock() smells like a magic
+ * debug feature and I wanted to keep the cond function in the
+ * main source file along with the comments instead of having
+ * two of the same in the headers.
+ */
+ return debug_rt_mutex_detect_deadlock(waiter, chwalk);
+}
+
/*
* Max number of times we'll walk the boosting chain:
*/
@@ -260,7 +350,8 @@
static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p)
{
- return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL;
+ struct rt_mutex_waiter *waiter = p->pi_blocked_on;
+ return rt_mutex_real_waiter(waiter) ? waiter->lock : NULL;
}
/*
@@ -283,21 +374,65 @@
* @top_task: the current top waiter
*
* Returns 0 or -EDEADLK.
+ *
+ * Chain walk basics and protection scope
+ *
+ * [R] refcount on task
+ * [P] task->pi_lock held
+ * [L] rtmutex->wait_lock held
+ *
+ * Step Description Protected by
+ * function arguments:
+ * @task [R]
+ * @orig_lock if != NULL @top_task is blocked on it
+ * @next_lock Unprotected. Cannot be
+ * dereferenced. Only used for
+ * comparison.
+ * @orig_waiter if != NULL @top_task is blocked on it
+ * @top_task current, or in case of proxy
+ * locking protected by calling
+ * code
+ * again:
+ * loop_sanity_check();
+ * retry:
+ * [1] lock(task->pi_lock); [R] acquire [P]
+ * [2] waiter = task->pi_blocked_on; [P]
+ * [3] check_exit_conditions_1(); [P]
+ * [4] lock = waiter->lock; [P]
+ * [5] if (!try_lock(lock->wait_lock)) { [P] try to acquire [L]
+ * unlock(task->pi_lock); release [P]
+ * goto retry;
+ * }
+ * [6] check_exit_conditions_2(); [P] + [L]
+ * [7] requeue_lock_waiter(lock, waiter); [P] + [L]
+ * [8] unlock(task->pi_lock); release [P]
+ * put_task_struct(task); release [R]
+ * [9] check_exit_conditions_3(); [L]
+ * [10] task = owner(lock); [L]
+ * get_task_struct(task); [L] acquire [R]
+ * lock(task->pi_lock); [L] acquire [P]
+ * [11] requeue_pi_waiter(tsk, waiters(lock));[P] + [L]
+ * [12] check_exit_conditions_4(); [P] + [L]
+ * [13] unlock(task->pi_lock); release [P]
+ * unlock(lock->wait_lock); release [L]
+ * goto again;
*/
static int rt_mutex_adjust_prio_chain(struct task_struct *task,
- int deadlock_detect,
+ enum rtmutex_chainwalk chwalk,
struct rt_mutex *orig_lock,
struct rt_mutex *next_lock,
struct rt_mutex_waiter *orig_waiter,
struct task_struct *top_task)
{
- struct rt_mutex *lock;
struct rt_mutex_waiter *waiter, *top_waiter = orig_waiter;
- int detect_deadlock, ret = 0, depth = 0;
+ struct rt_mutex_waiter *prerequeue_top_waiter;
+ int ret = 0, depth = 0;
+ struct rt_mutex *lock;
+ bool detect_deadlock;
unsigned long flags;
+ bool requeue = true;
- detect_deadlock = debug_rt_mutex_detect_deadlock(orig_waiter,
- deadlock_detect);
+ detect_deadlock = rt_mutex_cond_detect_deadlock(orig_waiter, chwalk);
/*
* The (de)boosting is a step by step approach with a lot of
@@ -306,6 +441,9 @@
* carefully whether things change under us.
*/
again:
+ /*
+ * We limit the lock chain length for each invocation.
+ */
if (++depth > max_lock_depth) {
static int prev_max;
@@ -323,19 +461,34 @@
return -EDEADLK;
}
+
+ /*
+ * We are fully preemptible here and only hold the refcount on
+ * @task. So everything can have changed under us since the
+ * caller or our own code below (goto retry/again) dropped all
+ * locks.
+ */
retry:
/*
- * Task can not go away as we did a get_task() before !
+ * [1] Task cannot go away as we did a get_task() before !
*/
raw_spin_lock_irqsave(&task->pi_lock, flags);
+ /*
+ * [2] Get the waiter on which @task is blocked on.
+ */
waiter = task->pi_blocked_on;
+
+ /*
+ * [3] check_exit_conditions_1() protected by task->pi_lock.
+ */
+
/*
* Check whether the end of the boosting chain has been
* reached or the state of the chain has changed while we
* dropped the locks.
*/
- if (!waiter)
+ if (!rt_mutex_real_waiter(waiter))
goto out_unlock_pi;
/*
@@ -367,20 +520,41 @@
goto out_unlock_pi;
/*
* If deadlock detection is off, we stop here if we
- * are not the top pi waiter of the task.
+ * are not the top pi waiter of the task. If deadlock
+ * detection is enabled we continue, but stop the
+ * requeueing in the chain walk.
*/
- if (!detect_deadlock && top_waiter != task_top_pi_waiter(task))
- goto out_unlock_pi;
+ if (top_waiter != task_top_pi_waiter(task)) {
+ if (!detect_deadlock)
+ goto out_unlock_pi;
+ else
+ requeue = false;
+ }
}
/*
- * When deadlock detection is off then we check, if further
- * priority adjustment is necessary.
+ * If the waiter priority is the same as the task priority
+ * then there is no further priority adjustment necessary. If
+ * deadlock detection is off, we stop the chain walk. If its
+ * enabled we continue, but stop the requeueing in the chain
+ * walk.
*/
- if (!detect_deadlock && waiter->list_entry.prio == task->prio)
- goto out_unlock_pi;
+ if (waiter->list_entry.prio == task->prio) {
+ if (!detect_deadlock)
+ goto out_unlock_pi;
+ else
+ requeue = false;
+ }
+ /*
+ * [4] Get the next lock
+ */
lock = waiter->lock;
+ /*
+ * [5] We need to trylock here as we are holding task->pi_lock,
+ * which is the reverse lock order versus the other rtmutex
+ * operations.
+ */
if (!raw_spin_trylock(&lock->wait_lock)) {
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
cpu_relax();
@@ -388,81 +562,183 @@
}
/*
+ * [6] check_exit_conditions_2() protected by task->pi_lock and
+ * lock->wait_lock.
+ *
* Deadlock detection. If the lock is the same as the original
* lock which caused us to walk the lock chain or if the
* current lock is owned by the task which initiated the chain
* walk, we detected a deadlock.
*/
if (lock == orig_lock || rt_mutex_owner(lock) == top_task) {
- debug_rt_mutex_deadlock(deadlock_detect, orig_waiter, lock);
+ debug_rt_mutex_deadlock(chwalk, orig_waiter, lock);
raw_spin_unlock(&lock->wait_lock);
ret = -EDEADLK;
goto out_unlock_pi;
}
- top_waiter = rt_mutex_top_waiter(lock);
-
- /* Requeue the waiter */
- plist_del(&waiter->list_entry, &lock->wait_list);
- waiter->list_entry.prio = task->prio;
- plist_add(&waiter->list_entry, &lock->wait_list);
-
- /* Release the task */
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
- if (!rt_mutex_owner(lock)) {
+ /*
+ * If we just follow the lock chain for deadlock detection, no
+ * need to do all the requeue operations. To avoid a truckload
+ * of conditionals around the various places below, just do the
+ * minimum chain walk checks.
+ */
+ if (!requeue) {
/*
- * If the requeue above changed the top waiter, then we need
- * to wake the new top waiter up to try to get the lock.
+ * No requeue[7] here. Just release @task [8]
*/
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ put_task_struct(task);
- if (top_waiter != rt_mutex_top_waiter(lock))
- wake_up_process(rt_mutex_top_waiter(lock)->task);
+ /*
+ * [9] check_exit_conditions_3 protected by lock->wait_lock.
+ * If there is no owner of the lock, end of chain.
+ */
+ if (!rt_mutex_owner(lock)) {
+ raw_spin_unlock(&lock->wait_lock);
+ return 0;
+ }
+
+ /* [10] Grab the next task, i.e. owner of @lock */
+ task = rt_mutex_owner(lock);
+ get_task_struct(task);
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+
+ /*
+ * No requeue [11] here. We just do deadlock detection.
+ *
+ * [12] Store whether owner is blocked
+ * itself. Decision is made after dropping the locks
+ */
+ next_lock = task_blocked_on_lock(task);
+ /*
+ * Get the top waiter for the next iteration
+ */
+ top_waiter = rt_mutex_top_waiter(lock);
+
+ /* [13] Drop locks */
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
raw_spin_unlock(&lock->wait_lock);
- goto out_put_task;
+
+ /* If owner is not blocked, end of chain. */
+ if (!next_lock)
+ goto out_put_task;
+ goto again;
}
+
+ /*
+ * Store the current top waiter before doing the requeue
+ * operation on @lock. We need it for the boost/deboost
+ * decision below.
+ */
+ prerequeue_top_waiter = rt_mutex_top_waiter(lock);
+
+ /* [7] Requeue the waiter in the lock waiter list. */
+ rt_mutex_dequeue(lock, waiter);
+ waiter->list_entry.prio = task->prio;
+ rt_mutex_enqueue(lock, waiter);
+
+ /* [8] Release the task */
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
put_task_struct(task);
- /* Grab the next task */
+ /*
+ * [9] check_exit_conditions_3 protected by lock->wait_lock.
+ *
+ * We must abort the chain walk if there is no lock owner even
+ * in the dead lock detection case, as we have nothing to
+ * follow here. This is the end of the chain we are walking.
+ */
+ if (!rt_mutex_owner(lock)) {
+ struct rt_mutex_waiter *lock_top_waiter;
+
+ /*
+ * If the requeue [7] above changed the top waiter,
+ * then we need to wake the new top waiter up to try
+ * to get the lock.
+ */
+ lock_top_waiter = rt_mutex_top_waiter(lock);
+ if (prerequeue_top_waiter != lock_top_waiter)
+ rt_mutex_wake_waiter(lock_top_waiter);
+ raw_spin_unlock(&lock->wait_lock);
+ return 0;
+ }
+
+ /* [10] Grab the next task, i.e. the owner of @lock */
task = rt_mutex_owner(lock);
get_task_struct(task);
raw_spin_lock_irqsave(&task->pi_lock, flags);
+ /* [11] requeue the pi waiters if necessary */
if (waiter == rt_mutex_top_waiter(lock)) {
- /* Boost the owner */
- plist_del(&top_waiter->pi_list_entry, &task->pi_waiters);
- waiter->pi_list_entry.prio = waiter->list_entry.prio;
- plist_add(&waiter->pi_list_entry, &task->pi_waiters);
+ /*
+ * The waiter became the new top (highest priority)
+ * waiter on the lock. Replace the previous top waiter
+ * in the owner tasks pi waiters list with this waiter
+ * and adjust the priority of the owner.
+ */
+ rt_mutex_dequeue_pi(task, prerequeue_top_waiter);
+ rt_mutex_enqueue_pi(task, waiter);
__rt_mutex_adjust_prio(task);
- } else if (top_waiter == waiter) {
- /* Deboost the owner */
- plist_del(&waiter->pi_list_entry, &task->pi_waiters);
+ } else if (prerequeue_top_waiter == waiter) {
+ /*
+ * The waiter was the top waiter on the lock, but is
+ * no longer the top prority waiter. Replace waiter in
+ * the owner tasks pi waiters list with the new top
+ * (highest priority) waiter and adjust the priority
+ * of the owner.
+ * The new top waiter is stored in @waiter so that
+ * @waiter == @top_waiter evaluates to true below and
+ * we continue to deboost the rest of the chain.
+ */
+ rt_mutex_dequeue_pi(task, waiter);
waiter = rt_mutex_top_waiter(lock);
- waiter->pi_list_entry.prio = waiter->list_entry.prio;
- plist_add(&waiter->pi_list_entry, &task->pi_waiters);
+ rt_mutex_enqueue_pi(task, waiter);
__rt_mutex_adjust_prio(task);
+ } else {
+ /*
+ * Nothing changed. No need to do any priority
+ * adjustment.
+ */
}
/*
+ * [12] check_exit_conditions_4() protected by task->pi_lock
+ * and lock->wait_lock. The actual decisions are made after we
+ * dropped the locks.
+ *
* Check whether the task which owns the current lock is pi
* blocked itself. If yes we store a pointer to the lock for
* the lock chain change detection above. After we dropped
* task->pi_lock next_lock cannot be dereferenced anymore.
*/
next_lock = task_blocked_on_lock(task);
-
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
-
+ /*
+ * Store the top waiter of @lock for the end of chain walk
+ * decision below.
+ */
top_waiter = rt_mutex_top_waiter(lock);
+
+ /* [13] Drop the locks */
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
raw_spin_unlock(&lock->wait_lock);
/*
+ * Make the actual exit decisions [12], based on the stored
+ * values.
+ *
* We reached the end of the lock chain. Stop right here. No
* point to go back just to figure that out.
*/
if (!next_lock)
goto out_put_task;
+ /*
+ * If the current waiter is not the top waiter on the lock,
+ * then we can stop the chain walk here if we are not in full
+ * deadlock detection mode.
+ */
if (!detect_deadlock && waiter != top_waiter)
goto out_put_task;
@@ -476,82 +752,146 @@
return ret;
}
+
+#define STEAL_NORMAL 0
+#define STEAL_LATERAL 1
+
+/*
+ * Note that RT tasks are excluded from lateral-steals to prevent the
+ * introduction of an unbounded latency
+ */
+static inline int lock_is_stealable(struct task_struct *task,
+ struct task_struct *pendowner, int mode)
+{
+ if (mode == STEAL_NORMAL || rt_task(task)) {
+ if (task->prio >= pendowner->prio)
+ return 0;
+ } else if (task->prio > pendowner->prio)
+ return 0;
+ return 1;
+}
+
/*
* Try to take an rt-mutex
*
* Must be called with lock->wait_lock held.
*
- * @lock: the lock to be acquired.
- * @task: the task which wants to acquire the lock
- * @waiter: the waiter that is queued to the lock's wait list. (could be NULL)
+ * @lock: The lock to be acquired.
+ * @task: The task which wants to acquire the lock
+ * @waiter: The waiter that is queued to the lock's wait list if the
+ * callsite called task_blocked_on_lock(), otherwise NULL
*/
-static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
- struct rt_mutex_waiter *waiter)
+static int
+__try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
+ struct rt_mutex_waiter *waiter, int mode)
{
+ unsigned long flags;
+
/*
- * We have to be careful here if the atomic speedups are
- * enabled, such that, when
- * - no other waiter is on the lock
- * - the lock has been released since we did the cmpxchg
- * the lock can be released or taken while we are doing the
- * checks and marking the lock with RT_MUTEX_HAS_WAITERS.
+ * Before testing whether we can acquire @lock, we set the
+ * RT_MUTEX_HAS_WAITERS bit in @lock->owner. This forces all
+ * other tasks which try to modify @lock into the slow path
+ * and they serialize on @lock->wait_lock.
*
- * The atomic acquire/release aware variant of
- * mark_rt_mutex_waiters uses a cmpxchg loop. After setting
- * the WAITERS bit, the atomic release / acquire can not
- * happen anymore and lock->wait_lock protects us from the
- * non-atomic case.
+ * The RT_MUTEX_HAS_WAITERS bit can have a transitional state
+ * as explained at the top of this file if and only if:
*
- * Note, that this might set lock->owner =
- * RT_MUTEX_HAS_WAITERS in the case the lock is not contended
- * any more. This is fixed up when we take the ownership.
- * This is the transitional state explained at the top of this file.
+ * - There is a lock owner. The caller must fixup the
+ * transient state if it does a trylock or leaves the lock
+ * function due to a signal or timeout.
+ *
+ * - @task acquires the lock and there are no other
+ * waiters. This is undone in rt_mutex_set_owner(@task) at
+ * the end of this function.
*/
mark_rt_mutex_waiters(lock);
+ /*
+ * If @lock has an owner, give up.
+ */
if (rt_mutex_owner(lock))
return 0;
/*
- * It will get the lock because of one of these conditions:
- * 1) there is no waiter
- * 2) higher priority than waiters
- * 3) it is top waiter
+ * If @waiter != NULL, @task has already enqueued the waiter
+ * into @lock waiter list. If @waiter == NULL then this is a
+ * trylock attempt.
*/
- if (rt_mutex_has_waiters(lock)) {
- if (task->prio >= rt_mutex_top_waiter(lock)->list_entry.prio) {
- if (!waiter || waiter != rt_mutex_top_waiter(lock))
- return 0;
- }
- }
-
- if (waiter || rt_mutex_has_waiters(lock)) {
- unsigned long flags;
- struct rt_mutex_waiter *top;
-
- raw_spin_lock_irqsave(&task->pi_lock, flags);
-
- /* remove the queued waiter. */
- if (waiter) {
- plist_del(&waiter->list_entry, &lock->wait_list);
- task->pi_blocked_on = NULL;
- }
+ if (waiter) {
+ /*
+ * If waiter is not the highest priority waiter of
+ * @lock, give up.
+ */
+ if (waiter != rt_mutex_top_waiter(lock))
+ return 0;
/*
- * We have to enqueue the top waiter(if it exists) into
- * task->pi_waiters list.
+ * We can acquire the lock. Remove the waiter from the
+ * lock waiters list.
+ */
+ rt_mutex_dequeue(lock, waiter);
+
+ } else {
+ /*
+ * If the lock has waiters already we check whether @task is
+ * eligible to take over the lock.
+ *
+ * If there are no other waiters, @task can acquire
+ * the lock. @task->pi_blocked_on is NULL, so it does
+ * not need to be dequeued.
*/
if (rt_mutex_has_waiters(lock)) {
- top = rt_mutex_top_waiter(lock);
- top->pi_list_entry.prio = top->list_entry.prio;
- plist_add(&top->pi_list_entry, &task->pi_waiters);
+ struct task_struct *pown = rt_mutex_top_waiter(lock)->task;
+
+ /*
+ * If @task->prio is greater than or equal to
+ * the top waiter priority (kernel view),
+ * @task lost.
+ */
+ if (task != pown && !lock_is_stealable(task, pown, mode))
+ return 0;
+
+ /*
+ * The current top waiter stays enqueued. We
+ * don't have to change anything in the lock
+ * waiters order.
+ */
+ } else {
+ /*
+ * No waiters. Take the lock without the
+ * pi_lock dance.@task->pi_blocked_on is NULL
+ * and we have no waiters to enqueue in @task
+ * pi waiters list.
+ */
+ goto takeit;
}
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
}
+ /*
+ * Clear @task->pi_blocked_on. Requires protection by
+ * @task->pi_lock. Redundant operation for the @waiter == NULL
+ * case, but conditionals are more expensive than a redundant
+ * store.
+ */
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+ task->pi_blocked_on = NULL;
+ /*
+ * Finish the lock acquisition. @task is the new owner. If
+ * other waiters exist we have to insert the highest priority
+ * waiter into @task->pi_waiters list.
+ */
+ if (rt_mutex_has_waiters(lock))
+ rt_mutex_enqueue_pi(task, rt_mutex_top_waiter(lock));
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+
+takeit:
/* We got the lock. */
debug_rt_mutex_lock(lock);
+ /*
+ * This either preserves the RT_MUTEX_HAS_WAITERS bit if there
+ * are still waiters or clears it.
+ */
rt_mutex_set_owner(lock, task);
rt_mutex_deadlock_account_lock(lock, task);
@@ -559,6 +899,13 @@
return 1;
}
+static inline int
+try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
+ struct rt_mutex_waiter *waiter)
+{
+ return __try_to_take_rt_mutex(lock, task, waiter, STEAL_NORMAL);
+}
+
/*
* Task blocks on lock.
*
@@ -569,7 +916,7 @@
static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
struct task_struct *task,
- int detect_deadlock)
+ enum rtmutex_chainwalk chwalk)
{
struct task_struct *owner = rt_mutex_owner(lock);
struct rt_mutex_waiter *top_waiter = waiter;
@@ -590,6 +937,23 @@
return -EDEADLK;
raw_spin_lock_irqsave(&task->pi_lock, flags);
+
+ /*
+ * In the case of futex requeue PI, this will be a proxy
+ * lock. The task will wake unaware that it is enqueueed on
+ * this lock. Avoid blocking on two locks and corrupting
+ * pi_blocked_on via the PI_WAKEUP_INPROGRESS
+ * flag. futex_wait_requeue_pi() sets this when it wakes up
+ * before requeue (due to a signal or timeout). Do not enqueue
+ * the task if PI_WAKEUP_INPROGRESS is set.
+ */
+ if (task != current && task->pi_blocked_on == PI_WAKEUP_INPROGRESS) {
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ return -EAGAIN;
+ }
+
+ BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on));
+
__rt_mutex_adjust_prio(task);
waiter->task = task;
waiter->lock = lock;
@@ -599,7 +963,7 @@
/* Get the top priority waiter on the lock */
if (rt_mutex_has_waiters(lock))
top_waiter = rt_mutex_top_waiter(lock);
- plist_add(&waiter->list_entry, &lock->wait_list);
+ rt_mutex_enqueue(lock, waiter);
task->pi_blocked_on = waiter;
@@ -610,13 +974,13 @@
raw_spin_lock_irqsave(&owner->pi_lock, flags);
if (waiter == rt_mutex_top_waiter(lock)) {
- plist_del(&top_waiter->pi_list_entry, &owner->pi_waiters);
- plist_add(&waiter->pi_list_entry, &owner->pi_waiters);
+ rt_mutex_dequeue_pi(owner, top_waiter);
+ rt_mutex_enqueue_pi(owner, waiter);
__rt_mutex_adjust_prio(owner);
- if (owner->pi_blocked_on)
+ if (rt_mutex_real_waiter(owner->pi_blocked_on))
chain_walk = 1;
- } else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock)) {
+ } else if (rt_mutex_cond_detect_deadlock(waiter, chwalk)) {
chain_walk = 1;
}
@@ -641,7 +1005,7 @@
raw_spin_unlock(&lock->wait_lock);
- res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock,
+ res = rt_mutex_adjust_prio_chain(owner, chwalk, lock,
next_lock, waiter, task);
raw_spin_lock(&lock->wait_lock);
@@ -672,7 +1036,7 @@
* boosted mode and go back to normal after releasing
* lock->wait_lock.
*/
- plist_del(&waiter->pi_list_entry, ¤t->pi_waiters);
+ rt_mutex_dequeue_pi(current, waiter);
/*
* As we are waking up the top waiter, and the waiter stays
@@ -691,7 +1055,7 @@
* long as we hold lock->wait_lock. The waiter task needs to
* acquire it in order to dequeue the waiter.
*/
- wake_up_process(waiter->task);
+ rt_mutex_wake_waiter(waiter);
}
/*
@@ -703,41 +1067,44 @@
static void remove_waiter(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter)
{
- int first = (waiter == rt_mutex_top_waiter(lock));
+ bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock));
struct task_struct *owner = rt_mutex_owner(lock);
struct rt_mutex *next_lock = NULL;
unsigned long flags;
raw_spin_lock_irqsave(¤t->pi_lock, flags);
- plist_del(&waiter->list_entry, &lock->wait_list);
+ rt_mutex_dequeue(lock, waiter);
current->pi_blocked_on = NULL;
raw_spin_unlock_irqrestore(¤t->pi_lock, flags);
- if (!owner)
+ /*
+ * Only update priority if the waiter was the highest priority
+ * waiter of the lock and there is an owner to update.
+ */
+ if (!owner || !is_top_waiter)
return;
- if (first) {
+ raw_spin_lock_irqsave(&owner->pi_lock, flags);
- raw_spin_lock_irqsave(&owner->pi_lock, flags);
+ rt_mutex_dequeue_pi(owner, waiter);
- plist_del(&waiter->pi_list_entry, &owner->pi_waiters);
+ if (rt_mutex_has_waiters(lock))
+ rt_mutex_enqueue_pi(owner, rt_mutex_top_waiter(lock));
- if (rt_mutex_has_waiters(lock)) {
- struct rt_mutex_waiter *next;
+ __rt_mutex_adjust_prio(owner);
- next = rt_mutex_top_waiter(lock);
- plist_add(&next->pi_list_entry, &owner->pi_waiters);
- }
- __rt_mutex_adjust_prio(owner);
-
- /* Store the lock on which owner is blocked or NULL */
+ /* Store the lock on which owner is blocked or NULL */
+ if (rt_mutex_real_waiter(owner->pi_blocked_on))
next_lock = task_blocked_on_lock(owner);
- raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
- }
+ raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
+ /*
+ * Don't walk the chain, if the owner task is not blocked
+ * itself.
+ */
if (!next_lock)
return;
@@ -746,7 +1113,8 @@
raw_spin_unlock(&lock->wait_lock);
- rt_mutex_adjust_prio_chain(owner, 0, lock, next_lock, NULL, current);
+ rt_mutex_adjust_prio_chain(owner, RT_MUTEX_MIN_CHAINWALK, lock,
+ next_lock, NULL, current);
raw_spin_lock(&lock->wait_lock);
}
@@ -765,24 +1133,373 @@
raw_spin_lock_irqsave(&task->pi_lock, flags);
waiter = task->pi_blocked_on;
- if (!waiter || waiter->list_entry.prio == task->prio) {
+ if (!rt_mutex_real_waiter(waiter) ||
+ waiter->list_entry.prio == task->prio) {
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
return;
}
next_lock = waiter->lock;
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
/* gets dropped in rt_mutex_adjust_prio_chain()! */
get_task_struct(task);
-
- rt_mutex_adjust_prio_chain(task, 0, NULL, next_lock, NULL, task);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL,
+ next_lock, NULL, task);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * preemptible spin_lock functions:
+ */
+static inline void rt_spin_lock_fastlock(struct rt_mutex *lock,
+ void (*slowfn)(struct rt_mutex *lock))
+{
+ might_sleep();
+
+ if (likely(rt_mutex_cmpxchg(lock, NULL, current)))
+ rt_mutex_deadlock_account_lock(lock, current);
+ else
+ slowfn(lock);
+}
+
+static inline void rt_spin_lock_fastunlock(struct rt_mutex *lock,
+ void (*slowfn)(struct rt_mutex *lock))
+{
+ if (likely(rt_mutex_cmpxchg(lock, current, NULL)))
+ rt_mutex_deadlock_account_unlock(current);
+ else
+ slowfn(lock);
+}
+
+#ifdef CONFIG_SMP
+/*
+ * Note that owner is a speculative pointer and dereferencing relies
+ * on rcu_read_lock() and the check against the lock owner.
+ */
+static int adaptive_wait(struct rt_mutex *lock,
+ struct task_struct *owner)
+{
+ int res = 0;
+
+ rcu_read_lock();
+ for (;;) {
+ if (owner != rt_mutex_owner(lock))
+ break;
+ /*
+ * Ensure that owner->on_cpu is dereferenced _after_
+ * checking the above to be valid.
+ */
+ barrier();
+ if (!owner->on_cpu) {
+ res = 1;
+ break;
+ }
+ cpu_relax();
+ }
+ rcu_read_unlock();
+ return res;
+}
+#else
+static int adaptive_wait(struct rt_mutex *lock,
+ struct task_struct *orig_owner)
+{
+ return 1;
+}
+#endif
+
+# define pi_lock(lock) raw_spin_lock_irq(lock)
+# define pi_unlock(lock) raw_spin_unlock_irq(lock)
+
+/*
+ * Slow path lock function spin_lock style: this variant is very
+ * careful not to miss any non-lock wakeups.
+ *
+ * We store the current state under p->pi_lock in p->saved_state and
+ * the try_to_wake_up() code handles this accordingly.
+ */
+static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
+{
+ struct task_struct *lock_owner, *self = current;
+ struct rt_mutex_waiter waiter, *top_waiter;
+ int ret;
+
+ rt_mutex_init_waiter(&waiter, true);
+
+ raw_spin_lock(&lock->wait_lock);
+ init_lists(lock);
+
+ if (__try_to_take_rt_mutex(lock, self, NULL, STEAL_LATERAL)) {
+ raw_spin_unlock(&lock->wait_lock);
+ return;
+ }
+
+ BUG_ON(rt_mutex_owner(lock) == self);
+
+ /*
+ * We save whatever state the task is in and we'll restore it
+ * after acquiring the lock taking real wakeups into account
+ * as well. We are serialized via pi_lock against wakeups. See
+ * try_to_wake_up().
+ */
+ pi_lock(&self->pi_lock);
+ self->saved_state = self->state;
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ pi_unlock(&self->pi_lock);
+
+ ret = task_blocks_on_rt_mutex(lock, &waiter, self, RT_MUTEX_MIN_CHAINWALK);
+ BUG_ON(ret);
+
+ for (;;) {
+ /* Try to acquire the lock again. */
+ if (__try_to_take_rt_mutex(lock, self, &waiter, STEAL_LATERAL))
+ break;
+
+ top_waiter = rt_mutex_top_waiter(lock);
+ lock_owner = rt_mutex_owner(lock);
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ debug_rt_mutex_print_deadlock(&waiter);
+
+ if (top_waiter != &waiter || adaptive_wait(lock, lock_owner))
+ schedule_rt_mutex(lock);
+
+ raw_spin_lock(&lock->wait_lock);
+
+ pi_lock(&self->pi_lock);
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ pi_unlock(&self->pi_lock);
+ }
+
+ /*
+ * Restore the task state to current->saved_state. We set it
+ * to the original state above and the try_to_wake_up() code
+ * has possibly updated it when a real (non-rtmutex) wakeup
+ * happened while we were blocked. Clear saved_state so
+ * try_to_wakeup() does not get confused.
+ */
+ pi_lock(&self->pi_lock);
+ __set_current_state(self->saved_state);
+ self->saved_state = TASK_RUNNING;
+ pi_unlock(&self->pi_lock);
+
+ /*
+ * try_to_take_rt_mutex() sets the waiter bit
+ * unconditionally. We might have to fix that up:
+ */
+ fixup_rt_mutex_waiters(lock);
+
+ BUG_ON(rt_mutex_has_waiters(lock) && &waiter == rt_mutex_top_waiter(lock));
+ BUG_ON(!plist_node_empty(&waiter.list_entry));
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ debug_rt_mutex_free_waiter(&waiter);
+}
+
+/*
+ * Slow path to release a rt_mutex spin_lock style
+ */
+static void __sched __rt_spin_lock_slowunlock(struct rt_mutex *lock)
+{
+ debug_rt_mutex_unlock(lock);
+
+ rt_mutex_deadlock_account_unlock(current);
+
+ if (!rt_mutex_has_waiters(lock)) {
+ lock->owner = NULL;
+ raw_spin_unlock(&lock->wait_lock);
+ return;
+ }
+
+ wakeup_next_waiter(lock);
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ /* Undo pi boosting.when necessary */
+ rt_mutex_adjust_prio(current);
+}
+
+static void noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
+{
+ raw_spin_lock(&lock->wait_lock);
+ __rt_spin_lock_slowunlock(lock);
+}
+
+static void noinline __sched rt_spin_lock_slowunlock_hirq(struct rt_mutex *lock)
+{
+ int ret;
+
+ do {
+ ret = raw_spin_trylock(&lock->wait_lock);
+ } while (!ret);
+
+ __rt_spin_lock_slowunlock(lock);
+}
+
+void __lockfunc rt_spin_lock(spinlock_t *lock)
+{
+ rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
+ spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+}
+EXPORT_SYMBOL(rt_spin_lock);
+
+void __lockfunc __rt_spin_lock(struct rt_mutex *lock)
+{
+ rt_spin_lock_fastlock(lock, rt_spin_lock_slowlock);
+}
+EXPORT_SYMBOL(__rt_spin_lock);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass)
+{
+ rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
+ spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+}
+EXPORT_SYMBOL(rt_spin_lock_nested);
+#endif
+
+void __lockfunc rt_spin_unlock(spinlock_t *lock)
+{
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ spin_release(&lock->dep_map, 1, _RET_IP_);
+ rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock);
+}
+EXPORT_SYMBOL(rt_spin_unlock);
+
+void __lockfunc rt_spin_unlock_after_trylock_in_irq(spinlock_t *lock)
+{
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ spin_release(&lock->dep_map, 1, _RET_IP_);
+ rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock_hirq);
+}
+
+void __lockfunc __rt_spin_unlock(struct rt_mutex *lock)
+{
+ rt_spin_lock_fastunlock(lock, rt_spin_lock_slowunlock);
+}
+EXPORT_SYMBOL(__rt_spin_unlock);
+
+/*
+ * Wait for the lock to get unlocked: instead of polling for an unlock
+ * (like raw spinlocks do), we lock and unlock, to force the kernel to
+ * schedule if there's contention:
+ */
+void __lockfunc rt_spin_unlock_wait(spinlock_t *lock)
+{
+ spin_lock(lock);
+ spin_unlock(lock);
+}
+EXPORT_SYMBOL(rt_spin_unlock_wait);
+
+int __lockfunc rt_spin_trylock(spinlock_t *lock)
+{
+ int ret = rt_mutex_trylock(&lock->lock);
+
+ if (ret)
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock);
+
+int __lockfunc rt_spin_trylock_bh(spinlock_t *lock)
+{
+ int ret;
+
+ local_bh_disable();
+ ret = rt_mutex_trylock(&lock->lock);
+ if (ret) {
+ migrate_disable();
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ } else
+ local_bh_enable();
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_bh);
+
+int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags)
+{
+ int ret;
+
+ *flags = 0;
+ ret = rt_mutex_trylock(&lock->lock);
+ if (ret) {
+ migrate_disable();
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_irqsave);
+
+int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock)
+{
+ /* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
+ if (atomic_add_unless(atomic, -1, 1))
+ return 0;
+ migrate_disable();
+ rt_spin_lock(lock);
+ if (atomic_dec_and_test(atomic))
+ return 1;
+ rt_spin_unlock(lock);
+ migrate_enable();
+ return 0;
+}
+EXPORT_SYMBOL(atomic_dec_and_spin_lock);
+
+void
+__rt_spin_lock_init(spinlock_t *lock, char *name, struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+ lockdep_init_map(&lock->dep_map, name, key, 0);
+#endif
+}
+EXPORT_SYMBOL(__rt_spin_lock_init);
+
+#endif /* PREEMPT_RT_FULL */
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+ struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+ struct ww_acquire_ctx *hold_ctx = ACCESS_ONCE(ww->ctx);
+
+ if (!hold_ctx)
+ return 0;
+
+ if (unlikely(ctx == hold_ctx))
+ return -EALREADY;
+
+ if (ctx->stamp - hold_ctx->stamp <= LONG_MAX &&
+ (ctx->stamp != hold_ctx->stamp || ctx > hold_ctx)) {
+#ifdef CONFIG_DEBUG_MUTEXES
+ DEBUG_LOCKS_WARN_ON(ctx->contending_lock);
+ ctx->contending_lock = ww;
+#endif
+ return -EDEADLK;
+ }
+
+ return 0;
+}
+#else
+static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+ BUG();
+ return 0;
+}
+
+#endif
+
/**
* __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop
* @lock: the rt_mutex to take
* @state: the state the task should block in (TASK_INTERRUPTIBLE
- * or TASK_UNINTERRUPTIBLE)
+ * or TASK_UNINTERRUPTIBLE)
* @timeout: the pre-initialized and started timer, or NULL for none
* @waiter: the pre-initialized rt_mutex_waiter
*
@@ -791,7 +1508,8 @@
static int __sched
__rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- struct rt_mutex_waiter *waiter)
+ struct rt_mutex_waiter *waiter,
+ struct ww_acquire_ctx *ww_ctx)
{
int ret = 0;
@@ -814,6 +1532,12 @@
break;
}
+ if (ww_ctx && ww_ctx->acquired > 0) {
+ ret = __mutex_lock_check_stamp(lock, ww_ctx);
+ if (ret)
+ break;
+ }
+
raw_spin_unlock(&lock->wait_lock);
debug_rt_mutex_print_deadlock(waiter);
@@ -827,6 +1551,82 @@
return ret;
}
+static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww,
+ struct ww_acquire_ctx *ww_ctx)
+{
+#ifdef CONFIG_DEBUG_MUTEXES
+ /*
+ * If this WARN_ON triggers, you used ww_mutex_lock to acquire,
+ * but released with a normal mutex_unlock in this call.
+ *
+ * This should never happen, always use ww_mutex_unlock.
+ */
+ DEBUG_LOCKS_WARN_ON(ww->ctx);
+
+ /*
+ * Not quite done after calling ww_acquire_done() ?
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->done_acquire);
+
+ if (ww_ctx->contending_lock) {
+ /*
+ * After -EDEADLK you tried to
+ * acquire a different ww_mutex? Bad!
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock != ww);
+
+ /*
+ * You called ww_mutex_lock after receiving -EDEADLK,
+ * but 'forgot' to unlock everything else first?
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->acquired > 0);
+ ww_ctx->contending_lock = NULL;
+ }
+
+ /*
+ * Naughty, using a different class will lead to undefined behavior!
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class);
+#endif
+ ww_ctx->acquired++;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+ struct ww_acquire_ctx *ww_ctx)
+{
+ struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+ struct rt_mutex_waiter *waiter;
+
+ /*
+ * This branch gets optimized out for the common case,
+ * and is only important for ww_mutex_lock.
+ */
+ ww_mutex_lock_acquired(ww, ww_ctx);
+ ww->ctx = ww_ctx;
+
+ /*
+ * Give any possible sleeping processes the chance to wake up,
+ * so they can recheck if they have to back off.
+ */
+ plist_for_each_entry(waiter, &lock->wait_list, list_entry) {
+
+ /* XXX debug rt mutex waiter wakeup */
+
+ BUG_ON(waiter->lock != lock);
+ rt_mutex_wake_waiter(waiter);
+ }
+}
+
+#else
+
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+ struct ww_acquire_ctx *ww_ctx)
+{
+ BUG();
+}
+#endif
+
static void rt_mutex_handle_deadlock(int res, int detect_deadlock,
struct rt_mutex_waiter *w)
{
@@ -853,17 +1653,21 @@
static int __sched
rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- int detect_deadlock)
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx)
{
struct rt_mutex_waiter waiter;
int ret = 0;
- debug_rt_mutex_init_waiter(&waiter);
+ rt_mutex_init_waiter(&waiter, false);
raw_spin_lock(&lock->wait_lock);
+ init_lists(lock);
/* Try to acquire the lock again: */
if (try_to_take_rt_mutex(lock, current, NULL)) {
+ if (ww_ctx)
+ ww_mutex_account_lock(lock, ww_ctx);
raw_spin_unlock(&lock->wait_lock);
return 0;
}
@@ -877,16 +1681,26 @@
timeout->task = NULL;
}
- ret = task_blocks_on_rt_mutex(lock, &waiter, current, detect_deadlock);
+ ret = task_blocks_on_rt_mutex(lock, &waiter, current, chwalk);
if (likely(!ret))
- ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
+ ret = __rt_mutex_slowlock(lock, state, timeout, &waiter, ww_ctx);
+ else if (ww_ctx) {
+ /* ww_mutex received EDEADLK, let it become EALREADY */
+ ret = __mutex_lock_check_stamp(lock, ww_ctx);
+ BUG_ON(!ret);
+ }
set_current_state(TASK_RUNNING);
if (unlikely(ret)) {
- remove_waiter(lock, &waiter);
- rt_mutex_handle_deadlock(ret, detect_deadlock, &waiter);
+ if (rt_mutex_has_waiters(lock))
+ remove_waiter(lock, &waiter);
+ /* ww_mutex want to report EDEADLK/EALREADY, let them */
+ if (!ww_ctx)
+ rt_mutex_handle_deadlock(ret, chwalk, &waiter);
+ } else if (ww_ctx) {
+ ww_mutex_account_lock(lock, ww_ctx);
}
/*
@@ -909,22 +1723,33 @@
/*
* Slow path try-lock function:
*/
-static inline int
-rt_mutex_slowtrylock(struct rt_mutex *lock)
+static inline int rt_mutex_slowtrylock(struct rt_mutex *lock)
{
- int ret = 0;
+ int ret;
- raw_spin_lock(&lock->wait_lock);
+ /*
+ * If the lock already has an owner we fail to get the lock.
+ * This can be done without taking the @lock->wait_lock as
+ * it is only being read, and this is a trylock anyway.
+ */
+ if (rt_mutex_owner(lock))
+ return 0;
- if (likely(rt_mutex_owner(lock) != current)) {
+ /*
+ * The mutex has currently no owner. Lock the wait lock and
+ * try to acquire the lock.
+ */
+ if (!raw_spin_trylock(&lock->wait_lock))
+ return 0;
+ init_lists(lock);
- ret = try_to_take_rt_mutex(lock, current, NULL);
- /*
- * try_to_take_rt_mutex() sets the lock waiters
- * bit unconditionally. Clean this up.
- */
- fixup_rt_mutex_waiters(lock);
- }
+ ret = try_to_take_rt_mutex(lock, current, NULL);
+
+ /*
+ * try_to_take_rt_mutex() sets the lock waiters bit
+ * unconditionally. Clean this up.
+ */
+ fixup_rt_mutex_waiters(lock);
raw_spin_unlock(&lock->wait_lock);
@@ -1002,30 +1827,35 @@
*/
static inline int
rt_mutex_fastlock(struct rt_mutex *lock, int state,
- int detect_deadlock,
+ struct ww_acquire_ctx *ww_ctx,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- int detect_deadlock))
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx))
{
- if (!detect_deadlock && likely(rt_mutex_cmpxchg(lock, NULL, current))) {
+ if (likely(rt_mutex_cmpxchg(lock, NULL, current))) {
rt_mutex_deadlock_account_lock(lock, current);
return 0;
} else
- return slowfn(lock, state, NULL, detect_deadlock);
+ return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK, ww_ctx);
}
static inline int
rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
- struct hrtimer_sleeper *timeout, int detect_deadlock,
+ struct hrtimer_sleeper *timeout,
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- int detect_deadlock))
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx))
{
- if (!detect_deadlock && likely(rt_mutex_cmpxchg(lock, NULL, current))) {
+ if (chwalk == RT_MUTEX_MIN_CHAINWALK &&
+ likely(rt_mutex_cmpxchg(lock, NULL, current))) {
rt_mutex_deadlock_account_lock(lock, current);
return 0;
} else
- return slowfn(lock, state, timeout, detect_deadlock);
+ return slowfn(lock, state, timeout, chwalk, ww_ctx);
}
static inline int
@@ -1058,54 +1888,80 @@
{
might_sleep();
- rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, 0, rt_mutex_slowlock);
+ rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, NULL, rt_mutex_slowlock);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock);
/**
* rt_mutex_lock_interruptible - lock a rt_mutex interruptible
*
- * @lock: the rt_mutex to be locked
- * @detect_deadlock: deadlock detection on/off
+ * @lock: the rt_mutex to be locked
*
* Returns:
- * 0 on success
- * -EINTR when interrupted by a signal
- * -EDEADLK when the lock would deadlock (when deadlock detection is on)
+ * 0 on success
+ * -EINTR when interrupted by a signal
*/
-int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock,
- int detect_deadlock)
+int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock)
{
might_sleep();
- return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE,
- detect_deadlock, rt_mutex_slowlock);
+ return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, NULL, rt_mutex_slowlock);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
+/*
+ * Futex variant with full deadlock detection.
+ */
+int rt_mutex_timed_futex_lock(struct rt_mutex *lock,
+ struct hrtimer_sleeper *timeout)
+{
+ might_sleep();
+
+ return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
+ RT_MUTEX_FULL_CHAINWALK, NULL,
+ rt_mutex_slowlock);
+}
+
+/**
+ * rt_mutex_lock_killable - lock a rt_mutex killable
+ *
+ * @lock: the rt_mutex to be locked
+ *
+ * Returns:
+ * 0 on success
+ * -EINTR when interrupted by a signal
+ * -EDEADLK when the lock would deadlock (when deadlock detection is on)
+ */
+int __sched rt_mutex_lock_killable(struct rt_mutex *lock)
+{
+ might_sleep();
+
+ return rt_mutex_fastlock(lock, TASK_KILLABLE,
+ NULL, rt_mutex_slowlock);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);
+
/**
* rt_mutex_timed_lock - lock a rt_mutex interruptible
* the timeout structure is provided
* by the caller
*
- * @lock: the rt_mutex to be locked
+ * @lock: the rt_mutex to be locked
* @timeout: timeout structure or NULL (no timeout)
- * @detect_deadlock: deadlock detection on/off
*
* Returns:
- * 0 on success
- * -EINTR when interrupted by a signal
+ * 0 on success
+ * -EINTR when interrupted by a signal
* -ETIMEDOUT when the timeout expired
- * -EDEADLK when the lock would deadlock (when deadlock detection is on)
*/
int
-rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout,
- int detect_deadlock)
+rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout)
{
might_sleep();
return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
- detect_deadlock, rt_mutex_slowlock);
+ RT_MUTEX_MIN_CHAINWALK,
+ NULL, rt_mutex_slowlock);
}
EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
@@ -1163,12 +2019,11 @@
void __rt_mutex_init(struct rt_mutex *lock, const char *name)
{
lock->owner = NULL;
- raw_spin_lock_init(&lock->wait_lock);
plist_head_init(&lock->wait_list);
debug_rt_mutex_init(lock, name);
}
-EXPORT_SYMBOL_GPL(__rt_mutex_init);
+EXPORT_SYMBOL(__rt_mutex_init);
/**
* rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a
@@ -1183,7 +2038,7 @@
void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner)
{
- __rt_mutex_init(lock, NULL);
+ rt_mutex_init(lock);
debug_rt_mutex_proxy_lock(lock, proxy_owner);
rt_mutex_set_owner(lock, proxy_owner);
rt_mutex_deadlock_account_lock(lock, proxy_owner);
@@ -1210,7 +2065,6 @@
* @lock: the rt_mutex to take
* @waiter: the pre-initialized rt_mutex_waiter
* @task: the task to prepare
- * @detect_deadlock: perform deadlock detection (1) or not (0)
*
* Returns:
* 0 - task blocked on lock
@@ -1221,7 +2075,7 @@
*/
int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
- struct task_struct *task, int detect_deadlock)
+ struct task_struct *task)
{
int ret;
@@ -1232,8 +2086,38 @@
return 1;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /*
+ * In PREEMPT_RT there's an added race.
+ * If the task, that we are about to requeue, times out,
+ * it can set the PI_WAKEUP_INPROGRESS. This tells the requeue
+ * to skip this task. But right after the task sets
+ * its pi_blocked_on to PI_WAKEUP_INPROGRESS it can then
+ * block on the spin_lock(&hb->lock), which in RT is an rtmutex.
+ * This will replace the PI_WAKEUP_INPROGRESS with the actual
+ * lock that it blocks on. We *must not* place this task
+ * on this proxy lock in that case.
+ *
+ * To prevent this race, we first take the task's pi_lock
+ * and check if it has updated its pi_blocked_on. If it has,
+ * we assume that it woke up and we return -EAGAIN.
+ * Otherwise, we set the task's pi_blocked_on to
+ * PI_REQUEUE_INPROGRESS, so that if the task is waking up
+ * it will know that we are in the process of requeuing it.
+ */
+ raw_spin_lock_irq(&task->pi_lock);
+ if (task->pi_blocked_on) {
+ raw_spin_unlock_irq(&task->pi_lock);
+ raw_spin_unlock(&lock->wait_lock);
+ return -EAGAIN;
+ }
+ task->pi_blocked_on = PI_REQUEUE_INPROGRESS;
+ raw_spin_unlock_irq(&task->pi_lock);
+#endif
+
/* We enforce deadlock detection for futexes */
- ret = task_blocks_on_rt_mutex(lock, waiter, task, 1);
+ ret = task_blocks_on_rt_mutex(lock, waiter, task,
+ RT_MUTEX_FULL_CHAINWALK);
if (ret && !rt_mutex_owner(lock)) {
/*
@@ -1245,7 +2129,7 @@
ret = 0;
}
- if (unlikely(ret))
+ if (ret && rt_mutex_has_waiters(lock))
remove_waiter(lock, waiter);
raw_spin_unlock(&lock->wait_lock);
@@ -1279,22 +2163,20 @@
* rt_mutex_finish_proxy_lock() - Complete lock acquisition
* @lock: the rt_mutex we were woken on
* @to: the timeout, null if none. hrtimer should already have
- * been started.
+ * been started.
* @waiter: the pre-initialized rt_mutex_waiter
- * @detect_deadlock: perform deadlock detection (1) or not (0)
*
* Complete the lock acquisition started our behalf by another thread.
*
* Returns:
* 0 - success
- * <0 - error, one of -EINTR, -ETIMEDOUT, or -EDEADLK
+ * <0 - error, one of -EINTR, -ETIMEDOUT
*
* Special API call for PI-futex requeue support
*/
int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
struct hrtimer_sleeper *to,
- struct rt_mutex_waiter *waiter,
- int detect_deadlock)
+ struct rt_mutex_waiter *waiter)
{
int ret;
@@ -1302,7 +2184,7 @@
set_current_state(TASK_INTERRUPTIBLE);
- ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter);
+ ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter, NULL);
set_current_state(TASK_RUNNING);
@@ -1319,3 +2201,89 @@
return ret;
}
+
+static inline int
+ww_mutex_deadlock_injection(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
+ unsigned tmp;
+
+ if (ctx->deadlock_inject_countdown-- == 0) {
+ tmp = ctx->deadlock_inject_interval;
+ if (tmp > UINT_MAX/4)
+ tmp = UINT_MAX;
+ else
+ tmp = tmp*2 + tmp + tmp/2;
+
+ ctx->deadlock_inject_interval = tmp;
+ ctx->deadlock_inject_countdown = tmp;
+ ctx->contending_lock = lock;
+
+ ww_mutex_unlock(lock);
+
+ return -EDEADLK;
+ }
+#endif
+
+ return 0;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+int __sched
+__ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx)
+{
+ int ret;
+
+ might_sleep();
+
+ mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map, _RET_IP_);
+ ret = rt_mutex_slowlock(&lock->base.lock, TASK_INTERRUPTIBLE, NULL, 0, ww_ctx);
+ if (ret)
+ mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+ else if (!ret && ww_ctx->acquired > 1)
+ return ww_mutex_deadlock_injection(lock, ww_ctx);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__ww_mutex_lock_interruptible);
+
+int __sched
+__ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx)
+{
+ int ret;
+
+ might_sleep();
+
+ mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map, _RET_IP_);
+ ret = rt_mutex_slowlock(&lock->base.lock, TASK_UNINTERRUPTIBLE, NULL, 0, ww_ctx);
+ if (ret)
+ mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+ else if (!ret && ww_ctx->acquired > 1)
+ return ww_mutex_deadlock_injection(lock, ww_ctx);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__ww_mutex_lock);
+
+void __sched ww_mutex_unlock(struct ww_mutex *lock)
+{
+ int nest = !!lock->ctx;
+
+ /*
+ * The unlocking fastpath is the 0->1 transition from 'locked'
+ * into 'unlocked' state:
+ */
+ if (nest) {
+#ifdef CONFIG_DEBUG_MUTEXES
+ DEBUG_LOCKS_WARN_ON(!lock->ctx->acquired);
+#endif
+ if (lock->ctx->acquired > 0)
+ lock->ctx->acquired--;
+ lock->ctx = NULL;
+ }
+
+ mutex_release(&lock->base.dep_map, nest, _RET_IP_);
+ rt_mutex_unlock(&lock->base.lock);
+}
+EXPORT_SYMBOL(ww_mutex_unlock);
+#endif
diff --git a/kernel/rtmutex.h b/kernel/rtmutex.h
index f6a1f3c..c406058 100644
--- a/kernel/rtmutex.h
+++ b/kernel/rtmutex.h
@@ -22,10 +22,15 @@
#define debug_rt_mutex_init(m, n) do { } while (0)
#define debug_rt_mutex_deadlock(d, a ,l) do { } while (0)
#define debug_rt_mutex_print_deadlock(w) do { } while (0)
-#define debug_rt_mutex_detect_deadlock(w,d) (d)
#define debug_rt_mutex_reset_waiter(w) do { } while (0)
static inline void rt_mutex_print_deadlock(struct rt_mutex_waiter *w)
{
WARN(1, "rtmutex deadlock detected\n");
}
+
+static inline bool debug_rt_mutex_detect_deadlock(struct rt_mutex_waiter *w,
+ enum rtmutex_chainwalk walk)
+{
+ return walk == RT_MUTEX_FULL_CHAINWALK;
+}
diff --git a/kernel/rtmutex_common.h b/kernel/rtmutex_common.h
index 1823c09..1192c0d 100644
--- a/kernel/rtmutex_common.h
+++ b/kernel/rtmutex_common.h
@@ -49,6 +49,7 @@
struct plist_node pi_list_entry;
struct task_struct *task;
struct rt_mutex *lock;
+ bool savestate;
#ifdef CONFIG_DEBUG_RT_MUTEXES
unsigned long ip;
struct pid *deadlock_task_pid;
@@ -102,8 +103,26 @@
}
/*
+ * Constants for rt mutex functions which have a selectable deadlock
+ * detection.
+ *
+ * RT_MUTEX_MIN_CHAINWALK: Stops the lock chain walk when there are
+ * no further PI adjustments to be made.
+ *
+ * RT_MUTEX_FULL_CHAINWALK: Invoke deadlock detection with a full
+ * walk of the lock chain.
+ */
+enum rtmutex_chainwalk {
+ RT_MUTEX_MIN_CHAINWALK,
+ RT_MUTEX_FULL_CHAINWALK,
+};
+
+/*
* PI-futex support (proxy locking functions, etc.):
*/
+#define PI_WAKEUP_INPROGRESS ((struct rt_mutex_waiter *) 1)
+#define PI_REQUEUE_INPROGRESS ((struct rt_mutex_waiter *) 2)
+
extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);
extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner);
@@ -111,12 +130,11 @@
struct task_struct *proxy_owner);
extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
- struct task_struct *task,
- int detect_deadlock);
+ struct task_struct *task);
extern int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
struct hrtimer_sleeper *to,
- struct rt_mutex_waiter *waiter,
- int detect_deadlock);
+ struct rt_mutex_waiter *waiter);
+extern int rt_mutex_timed_futex_lock(struct rt_mutex *l, struct hrtimer_sleeper *to);
#ifdef CONFIG_DEBUG_RT_MUTEXES
# include "rtmutex-debug.h"
@@ -124,4 +142,12 @@
# include "rtmutex.h"
#endif
+static inline void
+rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savestate)
+{
+ debug_rt_mutex_init_waiter(waiter);
+ waiter->task = NULL;
+ waiter->savestate = savestate;
+}
+
#endif
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 54adcf3..fc4b0c1 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -12,6 +12,7 @@
endif
obj-y += core.o proc.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o
+obj-y += work-simple.o
obj-$(CONFIG_SMP) += cpupri.o
obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
obj-$(CONFIG_SCHEDSTATS) += stats.o
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 602b6c0..6dafacf 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -270,7 +270,11 @@
* Number of tasks to iterate in a single balance run.
* Limited because this is done with IRQs disabled.
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
const_debug unsigned int sysctl_sched_nr_migrate = 32;
+#else
+const_debug unsigned int sysctl_sched_nr_migrate = 8;
+#endif
/*
* period over which we average the RT time consumption, measured
@@ -489,6 +493,7 @@
hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
rq->hrtick_timer.function = hrtick;
+ rq->hrtick_timer.irqsafe = 1;
}
#else /* CONFIG_SCHED_HRTICK */
static inline void hrtick_clear(struct rq *rq)
@@ -533,6 +538,37 @@
smp_send_reschedule(cpu);
}
+#ifdef CONFIG_PREEMPT_LAZY
+void resched_task_lazy(struct task_struct *p)
+{
+ int cpu;
+
+ if (!sched_feat(PREEMPT_LAZY)) {
+ resched_task(p);
+ return;
+ }
+
+ assert_raw_spin_locked(&task_rq(p)->lock);
+
+ if (test_tsk_need_resched(p))
+ return;
+
+ if (test_tsk_need_resched_lazy(p))
+ return;
+
+ set_tsk_need_resched_lazy(p);
+
+ cpu = task_cpu(p);
+ if (cpu == smp_processor_id())
+ return;
+
+ /* NEED_RESCHED_LAZY must be visible before we test polling */
+ smp_mb();
+ if (!tsk_is_polling(p))
+ smp_send_reschedule(cpu);
+}
+#endif
+
void resched_cpu(int cpu)
{
struct rq *rq = cpu_rq(cpu);
@@ -658,17 +694,34 @@
#endif /* CONFIG_NO_HZ_COMMON */
#ifdef CONFIG_NO_HZ_FULL
+
+static int ksoftirqd_running(void)
+{
+ struct task_struct *softirqd;
+
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL))
+ return 0;
+ softirqd = this_cpu_ksoftirqd();
+ if (softirqd && softirqd->on_rq)
+ return 1;
+ return 0;
+}
+
bool sched_can_stop_tick(void)
{
- struct rq *rq;
+ struct rq *rq;
- rq = this_rq();
+ rq = this_rq();
- /* Make sure rq->nr_running update is visible after the IPI */
- smp_rmb();
+ /* Make sure rq->nr_running update is visible after the IPI */
+ smp_rmb();
- /* More than one running task need preemption */
- if (rq->nr_running > 1)
+ /*
+ * More than one running task need preemption
+ *
+ * NOTE, RT: if ksoftirqd is awake, subtract it.
+ */
+ if (rq->nr_running - ksoftirqd_running() > 1)
return false;
return true;
@@ -697,6 +750,17 @@
assert_raw_spin_locked(&task_rq(p)->lock);
set_tsk_need_resched(p);
}
+#ifdef CONFIG_PREEMPT_LAZY
+void resched_task_lazy(struct task_struct *p)
+{
+ if (!sched_feat(PREEMPT_LAZY)) {
+ resched_task(p);
+ return;
+ }
+ assert_raw_spin_locked(&task_rq(p)->lock);
+ set_tsk_need_resched_lazy(p);
+}
+#endif
#endif /* CONFIG_SMP */
#if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \
@@ -1029,6 +1093,18 @@
static int migration_cpu_stop(void *data);
+static bool check_task_state(struct task_struct *p, long match_state)
+{
+ bool match = false;
+
+ raw_spin_lock_irq(&p->pi_lock);
+ if (p->state == match_state || p->saved_state == match_state)
+ match = true;
+ raw_spin_unlock_irq(&p->pi_lock);
+
+ return match;
+}
+
/*
* wait_task_inactive - wait for a thread to unschedule.
*
@@ -1073,7 +1149,7 @@
* is actually now running somewhere else!
*/
while (task_running(rq, p)) {
- if (match_state && unlikely(p->state != match_state))
+ if (match_state && !check_task_state(p, match_state))
return 0;
cpu_relax();
}
@@ -1088,7 +1164,8 @@
running = task_running(rq, p);
on_rq = p->on_rq;
ncsw = 0;
- if (!match_state || p->state == match_state)
+ if (!match_state || p->state == match_state
+ || p->saved_state == match_state)
ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
task_rq_unlock(rq, p, &flags);
@@ -1313,10 +1390,6 @@
{
activate_task(rq, p, en_flags);
p->on_rq = 1;
-
- /* if a worker is waking up, notify workqueue */
- if (p->flags & PF_WQ_WORKER)
- wq_worker_waking_up(p, cpu_of(rq));
}
/*
@@ -1326,9 +1399,9 @@
ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
{
check_preempt_curr(rq, p, wake_flags);
- trace_sched_wakeup(p, true);
-
p->state = TASK_RUNNING;
+ trace_sched_wakeup(p);
+
#ifdef CONFIG_SMP
if (p->sched_class->task_woken) {
/*
@@ -1495,8 +1568,29 @@
*/
smp_mb__before_spinlock();
raw_spin_lock_irqsave(&p->pi_lock, flags);
- if (!(p->state & state))
+ if (!(p->state & state)) {
+ /*
+ * The task might be running due to a spinlock sleeper
+ * wakeup. Check the saved state and set it to running
+ * if the wakeup condition is true.
+ */
+ if (!(wake_flags & WF_LOCK_SLEEPER)) {
+ if (p->saved_state & state) {
+ p->saved_state = TASK_RUNNING;
+ success = 1;
+ }
+ }
goto out;
+ }
+
+ /*
+ * If this is a regular wakeup, then we can unconditionally
+ * clear the saved state of a "lock sleeper".
+ */
+ if (!(wake_flags & WF_LOCK_SLEEPER))
+ p->saved_state = TASK_RUNNING;
+
+ trace_sched_waking(p);
success = 1; /* we're going to change ->state */
cpu = task_cpu(p);
@@ -1580,42 +1674,6 @@
}
/**
- * try_to_wake_up_local - try to wake up a local task with rq lock held
- * @p: the thread to be awakened
- *
- * Put @p on the run-queue if it's not already there. The caller must
- * ensure that this_rq() is locked, @p is bound to this_rq() and not
- * the current task.
- */
-static void try_to_wake_up_local(struct task_struct *p)
-{
- struct rq *rq = task_rq(p);
-
- if (WARN_ON_ONCE(rq != this_rq()) ||
- WARN_ON_ONCE(p == current))
- return;
-
- lockdep_assert_held(&rq->lock);
-
- if (!raw_spin_trylock(&p->pi_lock)) {
- raw_spin_unlock(&rq->lock);
- raw_spin_lock(&p->pi_lock);
- raw_spin_lock(&rq->lock);
- }
-
- if (!(p->state & TASK_NORMAL))
- goto out;
-
- if (!p->on_rq)
- ttwu_activate(rq, p, ENQUEUE_WAKEUP);
-
- ttwu_do_wakeup(rq, p, 0);
- ttwu_stat(p, smp_processor_id(), 0);
-out:
- raw_spin_unlock(&p->pi_lock);
-}
-
-/**
* wake_up_process - Wake up a specific process
* @p: The process to be woken up.
*
@@ -1633,6 +1691,18 @@
}
EXPORT_SYMBOL(wake_up_process);
+/**
+ * wake_up_lock_sleeper - Wake up a specific process blocked on a "sleeping lock"
+ * @p: The process to be woken up.
+ *
+ * Same as wake_up_process() above, but wake_flags=WF_LOCK_SLEEPER to indicate
+ * the nature of the wakeup.
+ */
+int wake_up_lock_sleeper(struct task_struct *p)
+{
+ return try_to_wake_up(p, TASK_ALL, WF_LOCK_SLEEPER);
+}
+
int wake_up_state(struct task_struct *p, unsigned int state)
{
return try_to_wake_up(p, state, 0);
@@ -1770,6 +1840,9 @@
/* Want to start with kernel preemption disabled. */
task_thread_info(p)->preempt_count = 1;
#endif
+#ifdef CONFIG_HAVE_PREEMPT_LAZY
+ task_thread_info(p)->preempt_lazy_count = 0;
+#endif
#ifdef CONFIG_SMP
plist_node_init(&p->pushable_tasks, MAX_PRIO);
#endif
@@ -1804,7 +1877,7 @@
rq = __task_rq_lock(p);
activate_task(rq, p, 0);
p->on_rq = 1;
- trace_sched_wakeup_new(p, true);
+ trace_sched_wakeup_new(p);
check_preempt_curr(rq, p, WF_FORK);
#ifdef CONFIG_SMP
if (p->sched_class->task_woken)
@@ -1936,8 +2009,12 @@
finish_arch_post_lock_switch();
fire_sched_in_preempt_notifiers(current);
+ /*
+ * We use mmdrop_delayed() here so we don't have to do the
+ * full __mmdrop() when we are the last user.
+ */
if (mm)
- mmdrop(mm);
+ mmdrop_delayed(mm);
if (unlikely(prev_state == TASK_DEAD)) {
/*
* Remove function-return probe instances associated with this
@@ -2263,16 +2340,6 @@
}
#endif
-notrace unsigned long get_parent_ip(unsigned long addr)
-{
- if (in_lock_functions(addr)) {
- addr = CALLER_ADDR2;
- if (in_lock_functions(addr))
- addr = CALLER_ADDR3;
- }
- return addr;
-}
-
#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
defined(CONFIG_PREEMPT_TRACER))
@@ -2293,8 +2360,13 @@
DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
PREEMPT_MASK - 10);
#endif
- if (preempt_count() == val)
- trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ if (preempt_count() == val) {
+ unsigned long ip = get_lock_parent_ip();
+#ifdef CONFIG_DEBUG_PREEMPT
+ current->preempt_disable_ip = ip;
+#endif
+ trace_preempt_off(CALLER_ADDR0, ip);
+ }
}
EXPORT_SYMBOL(add_preempt_count);
@@ -2315,7 +2387,7 @@
#endif
if (preempt_count() == val)
- trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip());
preempt_count() -= val;
}
EXPORT_SYMBOL(sub_preempt_count);
@@ -2337,6 +2409,13 @@
print_modules();
if (irqs_disabled())
print_irqtrace_events(prev);
+#ifdef CONFIG_DEBUG_PREEMPT
+ if (in_atomic_preempt_off()) {
+ pr_err("Preemption disabled at:");
+ print_ip_sym(current->preempt_disable_ip);
+ pr_cont("\n");
+ }
+#endif
dump_stack();
add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
}
@@ -2360,6 +2439,133 @@
schedstat_inc(this_rq(), sched_count);
}
+#if defined(CONFIG_PREEMPT_RT_FULL) && defined(CONFIG_SMP)
+#define MIGRATE_DISABLE_SET_AFFIN (1<<30) /* Can't make a negative */
+#define migrate_disabled_updated(p) ((p)->migrate_disable & MIGRATE_DISABLE_SET_AFFIN)
+#define migrate_disable_count(p) ((p)->migrate_disable & ~MIGRATE_DISABLE_SET_AFFIN)
+
+static inline void update_migrate_disable(struct task_struct *p)
+{
+ const struct cpumask *mask;
+
+ if (likely(!p->migrate_disable))
+ return;
+
+ /* Did we already update affinity? */
+ if (unlikely(migrate_disabled_updated(p)))
+ return;
+
+ /*
+ * Since this is always current we can get away with only locking
+ * rq->lock, the ->cpus_allowed value can normally only be changed
+ * while holding both p->pi_lock and rq->lock, but seeing that this
+ * is current, we cannot actually be waking up, so all code that
+ * relies on serialization against p->pi_lock is out of scope.
+ *
+ * Having rq->lock serializes us against things like
+ * set_cpus_allowed_ptr() that can still happen concurrently.
+ */
+ mask = tsk_cpus_allowed(p);
+
+ if (p->sched_class->set_cpus_allowed)
+ p->sched_class->set_cpus_allowed(p, mask);
+ /* mask==cpumask_of(task_cpu(p)) which has a cpumask_weight==1 */
+ p->nr_cpus_allowed = 1;
+
+ /* Let migrate_enable know to fix things back up */
+ p->migrate_disable |= MIGRATE_DISABLE_SET_AFFIN;
+}
+
+void migrate_disable(void)
+{
+ struct task_struct *p = current;
+
+ if (in_atomic() || irqs_disabled()) {
+#ifdef CONFIG_SCHED_DEBUG
+ p->migrate_disable_atomic++;
+#endif
+ return;
+ }
+
+#ifdef CONFIG_SCHED_DEBUG
+ if (unlikely(p->migrate_disable_atomic)) {
+ tracing_off();
+ WARN_ON_ONCE(1);
+ }
+#endif
+
+ if (p->migrate_disable) {
+ p->migrate_disable++;
+ return;
+ }
+
+ preempt_disable();
+ preempt_lazy_disable();
+ pin_current_cpu();
+ p->migrate_disable = 1;
+ preempt_enable();
+}
+EXPORT_SYMBOL(migrate_disable);
+
+void migrate_enable(void)
+{
+ struct task_struct *p = current;
+ const struct cpumask *mask;
+ unsigned long flags;
+ struct rq *rq;
+
+ if (in_atomic() || irqs_disabled()) {
+#ifdef CONFIG_SCHED_DEBUG
+ p->migrate_disable_atomic--;
+#endif
+ return;
+ }
+
+#ifdef CONFIG_SCHED_DEBUG
+ if (unlikely(p->migrate_disable_atomic)) {
+ tracing_off();
+ WARN_ON_ONCE(1);
+ }
+#endif
+ WARN_ON_ONCE(p->migrate_disable <= 0);
+
+ if (migrate_disable_count(p) > 1) {
+ p->migrate_disable--;
+ return;
+ }
+
+ preempt_disable();
+ if (unlikely(migrate_disabled_updated(p))) {
+ /*
+ * Undo whatever update_migrate_disable() did, also see there
+ * about locking.
+ */
+ rq = this_rq();
+ raw_spin_lock_irqsave(&rq->lock, flags);
+
+ /*
+ * Clearing migrate_disable causes tsk_cpus_allowed to
+ * show the tasks original cpu affinity.
+ */
+ p->migrate_disable = 0;
+ mask = tsk_cpus_allowed(p);
+ if (p->sched_class->set_cpus_allowed)
+ p->sched_class->set_cpus_allowed(p, mask);
+ p->nr_cpus_allowed = cpumask_weight(mask);
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
+ } else
+ p->migrate_disable = 0;
+
+ unpin_current_cpu();
+ preempt_enable();
+ preempt_lazy_enable();
+}
+EXPORT_SYMBOL(migrate_enable);
+#else
+static inline void update_migrate_disable(struct task_struct *p) { }
+#define migrate_disabled_updated(p) 0
+#endif
+
static void put_prev_task(struct rq *rq, struct task_struct *prev)
{
if (prev->on_rq || rq->skip_clock_update < 0)
@@ -2459,6 +2665,8 @@
smp_mb__before_spinlock();
raw_spin_lock_irq(&rq->lock);
+ update_migrate_disable(prev);
+
switch_count = &prev->nivcsw;
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
if (unlikely(signal_pending_state(prev->state, prev))) {
@@ -2466,19 +2674,6 @@
} else {
deactivate_task(rq, prev, DEQUEUE_SLEEP);
prev->on_rq = 0;
-
- /*
- * If a worker went to sleep, notify and ask workqueue
- * whether it wants to wake up a task to maintain
- * concurrency.
- */
- if (prev->flags & PF_WQ_WORKER) {
- struct task_struct *to_wakeup;
-
- to_wakeup = wq_worker_sleeping(prev, cpu);
- if (to_wakeup)
- try_to_wake_up_local(to_wakeup);
- }
}
switch_count = &prev->nvcsw;
}
@@ -2491,6 +2686,7 @@
put_prev_task(rq, prev);
next = pick_next_task(rq);
clear_tsk_need_resched(prev);
+ clear_tsk_need_resched_lazy(prev);
rq->skip_clock_update = 0;
if (likely(prev != next)) {
@@ -2519,9 +2715,20 @@
static inline void sched_submit_work(struct task_struct *tsk)
{
- if (!tsk->state || tsk_is_pi_blocked(tsk))
+ if (!tsk->state)
return;
/*
+ * If a worker went to sleep, notify and ask workqueue whether
+ * it wants to wake up a task to maintain concurrency.
+ */
+ if (tsk->flags & PF_WQ_WORKER)
+ wq_worker_sleeping(tsk);
+
+
+ if (tsk_is_pi_blocked(tsk))
+ return;
+
+ /*
* If we are going to sleep and we have plugged IO queued,
* make sure to submit it to avoid deadlocks.
*/
@@ -2529,12 +2736,19 @@
blk_schedule_flush_plug(tsk);
}
+static inline void sched_update_worker(struct task_struct *tsk)
+{
+ if (tsk->flags & PF_WQ_WORKER)
+ wq_worker_running(tsk);
+}
+
asmlinkage void __sched schedule(void)
{
struct task_struct *tsk = current;
sched_submit_work(tsk);
__schedule();
+ sched_update_worker(tsk);
}
EXPORT_SYMBOL(schedule);
@@ -2565,6 +2779,30 @@
preempt_disable();
}
+#ifdef CONFIG_PREEMPT_LAZY
+/*
+ * If TIF_NEED_RESCHED is then we allow to be scheduled away since this is
+ * set by a RT task. Oterwise we try to avoid beeing scheduled out as long as
+ * preempt_lazy_count counter >0.
+ */
+static __always_inline int preemptible_lazy(void)
+{
+ if (test_thread_flag(TIF_NEED_RESCHED))
+ return 1;
+ if (current_thread_info()->preempt_lazy_count)
+ return 0;
+ return 1;
+}
+
+#else
+
+static inline int preemptible_lazy(void)
+{
+ return 1;
+}
+
+#endif
+
#ifdef CONFIG_PREEMPT
/*
* this is the entry point to schedule() from in-kernel preemption
@@ -2579,10 +2817,21 @@
*/
if (likely(!preemptible()))
return;
+ if (!preemptible_lazy())
+ return;
do {
add_preempt_count_notrace(PREEMPT_ACTIVE);
+ /*
+ * The add/subtract must not be traced by the function
+ * tracer. But we still want to account for the
+ * preempt off latency tracer. Since the _notrace versions
+ * of add/subtract skip the accounting for latency tracer
+ * we must force it manually.
+ */
+ start_critical_timings();
__schedule();
+ stop_critical_timings();
sub_preempt_count_notrace(PREEMPT_ACTIVE);
/*
@@ -2755,10 +3004,10 @@
{
unsigned long flags;
- spin_lock_irqsave(&x->wait.lock, flags);
+ raw_spin_lock_irqsave(&x->wait.lock, flags);
x->done++;
- __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
- spin_unlock_irqrestore(&x->wait.lock, flags);
+ __swait_wake_locked(&x->wait, TASK_NORMAL, 1);
+ raw_spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete);
@@ -2775,10 +3024,10 @@
{
unsigned long flags;
- spin_lock_irqsave(&x->wait.lock, flags);
+ raw_spin_lock_irqsave(&x->wait.lock, flags);
x->done += UINT_MAX/2;
- __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
- spin_unlock_irqrestore(&x->wait.lock, flags);
+ __swait_wake_locked(&x->wait, TASK_NORMAL, 0);
+ raw_spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete_all);
@@ -2787,20 +3036,20 @@
long (*action)(long), long timeout, int state)
{
if (!x->done) {
- DECLARE_WAITQUEUE(wait, current);
+ DEFINE_SWAITER(wait);
- __add_wait_queue_tail_exclusive(&x->wait, &wait);
+ swait_prepare_locked(&x->wait, &wait);
do {
if (signal_pending_state(state, current)) {
timeout = -ERESTARTSYS;
break;
}
__set_current_state(state);
- spin_unlock_irq(&x->wait.lock);
+ raw_spin_unlock_irq(&x->wait.lock);
timeout = action(timeout);
- spin_lock_irq(&x->wait.lock);
+ raw_spin_lock_irq(&x->wait.lock);
} while (!x->done && timeout);
- __remove_wait_queue(&x->wait, &wait);
+ swait_finish_locked(&x->wait, &wait);
if (!x->done)
return timeout;
}
@@ -2814,9 +3063,9 @@
{
might_sleep();
- spin_lock_irq(&x->wait.lock);
+ raw_spin_lock_irq(&x->wait.lock);
timeout = do_wait_for_common(x, action, timeout, state);
- spin_unlock_irq(&x->wait.lock);
+ raw_spin_unlock_irq(&x->wait.lock);
return timeout;
}
@@ -2992,12 +3241,12 @@
unsigned long flags;
int ret = 1;
- spin_lock_irqsave(&x->wait.lock, flags);
+ raw_spin_lock_irqsave(&x->wait.lock, flags);
if (!x->done)
ret = 0;
else
x->done--;
- spin_unlock_irqrestore(&x->wait.lock, flags);
+ raw_spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}
EXPORT_SYMBOL(try_wait_for_completion);
@@ -3015,10 +3264,10 @@
unsigned long flags;
int ret = 1;
- spin_lock_irqsave(&x->wait.lock, flags);
+ raw_spin_lock_irqsave(&x->wait.lock, flags);
if (!x->done)
ret = 0;
- spin_unlock_irqrestore(&x->wait.lock, flags);
+ raw_spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}
EXPORT_SYMBOL(completion_done);
@@ -3079,7 +3328,8 @@
* This function changes the 'effective' priority of a task. It does
* not touch ->normal_prio like __setscheduler().
*
- * Used by the rt_mutex code to implement priority inheritance logic.
+ * Used by the rt_mutex code to implement priority inheritance
+ * logic. Call site only calls if the priority of the task changed.
*/
void rt_mutex_setprio(struct task_struct *p, int prio)
{
@@ -3317,20 +3567,25 @@
return pid ? find_task_by_vpid(pid) : current;
}
-/* Actually do priority change: must hold rq lock. */
-static void
-__setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
+static void __setscheduler_params(struct task_struct *p, int policy, int prio)
{
p->policy = policy;
p->rt_priority = prio;
p->normal_prio = normal_prio(p);
+ set_load_weight(p);
+}
+
+/* Actually do priority change: must hold rq lock. */
+static void
+__setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
+{
+ __setscheduler_params(p, policy, prio);
/* we are holding p->pi_lock already */
p->prio = rt_mutex_getprio(p);
if (rt_prio(p->prio))
p->sched_class = &rt_sched_class;
else
p->sched_class = &fair_sched_class;
- set_load_weight(p);
}
/*
@@ -3352,6 +3607,7 @@
static int __sched_setscheduler(struct task_struct *p, int policy,
const struct sched_param *param, bool user)
{
+ int newprio = MAX_RT_PRIO - 1 - param->sched_priority;
int retval, oldprio, oldpolicy = -1, on_rq, running;
unsigned long flags;
const struct sched_class *prev_class;
@@ -3447,10 +3703,13 @@
}
/*
- * If not changing anything there's no need to proceed further:
+ * If not changing anything there's no need to proceed
+ * further, but store a possible modification of
+ * reset_on_fork.
*/
if (unlikely(policy == p->policy && (!rt_policy(policy) ||
param->sched_priority == p->rt_priority))) {
+ p->sched_reset_on_fork = reset_on_fork;
task_rq_unlock(rq, p, &flags);
return 0;
}
@@ -3476,6 +3735,25 @@
task_rq_unlock(rq, p, &flags);
goto recheck;
}
+
+ p->sched_reset_on_fork = reset_on_fork;
+ oldprio = p->prio;
+
+ /*
+ * Special case for priority boosted tasks.
+ *
+ * If the new priority is lower or equal (user space view)
+ * than the current (boosted) priority, we just store the new
+ * normal parameters and do not touch the scheduler class and
+ * the runqueue. This will be done when the task deboost
+ * itself.
+ */
+ if (rt_mutex_check_prio(p, newprio)) {
+ __setscheduler_params(p, policy, param->sched_priority);
+ task_rq_unlock(rq, p, &flags);
+ return 0;
+ }
+
on_rq = p->on_rq;
running = task_current(rq, p);
if (on_rq)
@@ -3483,17 +3761,18 @@
if (running)
p->sched_class->put_prev_task(rq, p);
- p->sched_reset_on_fork = reset_on_fork;
-
- oldprio = p->prio;
prev_class = p->sched_class;
__setscheduler(rq, p, policy, param->sched_priority);
if (running)
p->sched_class->set_curr_task(rq);
- if (on_rq)
- enqueue_task(rq, p, 0);
-
+ if (on_rq) {
+ /*
+ * We enqueue to tail when the priority of a task is
+ * increased (user space view).
+ */
+ enqueue_task(rq, p, oldprio <= p->prio ? ENQUEUE_HEAD : 0);
+ }
check_class_changed(rq, p, prev_class, oldprio);
preempt_disable(); /* avoid rq from going away on us */
task_rq_unlock(rq, p, &flags);
@@ -3876,9 +4155,17 @@
static void __cond_resched(void)
{
- add_preempt_count(PREEMPT_ACTIVE);
- __schedule();
- sub_preempt_count(PREEMPT_ACTIVE);
+ do {
+ add_preempt_count(PREEMPT_ACTIVE);
+ __schedule();
+ sub_preempt_count(PREEMPT_ACTIVE);
+ /*
+ * Check again in case we missed a preemption
+ * opportunity between schedule and now.
+ */
+ barrier();
+
+ } while (need_resched());
}
int __sched _cond_resched(void)
@@ -3919,6 +4206,7 @@
}
EXPORT_SYMBOL(__cond_resched_lock);
+#ifndef CONFIG_PREEMPT_RT_FULL
int __sched __cond_resched_softirq(void)
{
BUG_ON(!in_softirq());
@@ -3932,6 +4220,7 @@
return 0;
}
EXPORT_SYMBOL(__cond_resched_softirq);
+#endif
/**
* yield - yield the current processor to other threads.
@@ -4282,6 +4571,7 @@
rcu_read_unlock();
rq->curr = rq->idle = idle;
+ idle->on_rq = 1;
#if defined(CONFIG_SMP)
idle->on_cpu = 1;
#endif
@@ -4289,7 +4579,9 @@
/* Set the preempt count _outside_ the spinlocks! */
task_thread_info(idle)->preempt_count = 0;
-
+#ifdef CONFIG_HAVE_PREEMPT_LAZY
+ task_thread_info(idle)->preempt_lazy_count = 0;
+#endif
/*
* The idle tasks have their own, simple scheduling class:
*/
@@ -4304,11 +4596,90 @@
#ifdef CONFIG_SMP
void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
{
- if (p->sched_class && p->sched_class->set_cpus_allowed)
- p->sched_class->set_cpus_allowed(p, new_mask);
-
+ if (!migrate_disabled_updated(p)) {
+ if (p->sched_class && p->sched_class->set_cpus_allowed)
+ p->sched_class->set_cpus_allowed(p, new_mask);
+ p->nr_cpus_allowed = cpumask_weight(new_mask);
+ }
cpumask_copy(&p->cpus_allowed, new_mask);
- p->nr_cpus_allowed = cpumask_weight(new_mask);
+}
+
+static DEFINE_PER_CPU(struct cpumask, sched_cpumasks);
+static DEFINE_MUTEX(sched_down_mutex);
+static cpumask_t sched_down_cpumask;
+
+void tell_sched_cpu_down_begin(int cpu)
+{
+ mutex_lock(&sched_down_mutex);
+ cpumask_set_cpu(cpu, &sched_down_cpumask);
+ mutex_unlock(&sched_down_mutex);
+}
+
+void tell_sched_cpu_down_done(int cpu)
+{
+ mutex_lock(&sched_down_mutex);
+ cpumask_clear_cpu(cpu, &sched_down_cpumask);
+ mutex_unlock(&sched_down_mutex);
+}
+
+/**
+ * migrate_me - try to move the current task off this cpu
+ *
+ * Used by the pin_current_cpu() code to try to get tasks
+ * to move off the current CPU as it is going down.
+ * It will only move the task if the task isn't pinned to
+ * the CPU (with migrate_disable, affinity or NO_SETAFFINITY)
+ * and the task has to be in a RUNNING state. Otherwise the
+ * movement of the task will wake it up (change its state
+ * to running) when the task did not expect it.
+ *
+ * Returns 1 if it succeeded in moving the current task
+ * 0 otherwise.
+ */
+int migrate_me(void)
+{
+ struct task_struct *p = current;
+ struct migration_arg arg;
+ struct cpumask *cpumask;
+ struct cpumask *mask;
+ unsigned long flags;
+ unsigned int dest_cpu;
+ struct rq *rq;
+
+ /*
+ * We can not migrate tasks bounded to a CPU or tasks not
+ * running. The movement of the task will wake it up.
+ */
+ if (p->flags & PF_NO_SETAFFINITY || p->state)
+ return 0;
+
+ mutex_lock(&sched_down_mutex);
+ rq = task_rq_lock(p, &flags);
+
+ cpumask = &__get_cpu_var(sched_cpumasks);
+ mask = &p->cpus_allowed;
+
+ cpumask_andnot(cpumask, mask, &sched_down_cpumask);
+
+ if (!cpumask_weight(cpumask)) {
+ /* It's only on this CPU? */
+ task_rq_unlock(rq, p, &flags);
+ mutex_unlock(&sched_down_mutex);
+ return 0;
+ }
+
+ dest_cpu = cpumask_any_and(cpu_active_mask, cpumask);
+
+ arg.task = p;
+ arg.dest_cpu = dest_cpu;
+
+ task_rq_unlock(rq, p, &flags);
+
+ stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
+ tlb_migrate_finish(p->mm);
+ mutex_unlock(&sched_down_mutex);
+
+ return 1;
}
/*
@@ -4354,7 +4725,7 @@
do_set_cpus_allowed(p, new_mask);
/* Can the task run on the task's current CPU? If so, we're done */
- if (cpumask_test_cpu(task_cpu(p), new_mask))
+ if (cpumask_test_cpu(task_cpu(p), new_mask) || __migrate_disabled(p))
goto out;
dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
@@ -4443,6 +4814,8 @@
#ifdef CONFIG_HOTPLUG_CPU
+static DEFINE_PER_CPU(struct mm_struct *, idle_last_mm);
+
/*
* Ensures that the idle task is using init_mm right before its cpu goes
* offline.
@@ -4455,7 +4828,12 @@
if (mm != &init_mm)
switch_mm(mm, &init_mm, current);
- mmdrop(mm);
+
+ /*
+ * Defer the cleanup to an alive cpu. On RT we can neither
+ * call mmdrop() nor mmdrop_delayed() from here.
+ */
+ per_cpu(idle_last_mm, smp_processor_id()) = mm;
}
/*
@@ -4780,6 +5158,10 @@
case CPU_DEAD:
calc_load_migrate(rq);
+ if (per_cpu(idle_last_mm, cpu)) {
+ mmdrop(per_cpu(idle_last_mm, cpu));
+ per_cpu(idle_last_mm, cpu) = NULL;
+ }
break;
#endif
}
@@ -6659,7 +7041,8 @@
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
static inline int preempt_count_equals(int preempt_offset)
{
- int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth();
+ int nested = (preempt_count() & ~PREEMPT_ACTIVE) +
+ sched_rcu_preempt_depth();
return (nested == preempt_offset);
}
@@ -6669,7 +7052,8 @@
static unsigned long prev_jiffy; /* ratelimiting */
rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */
- if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) ||
+ if ((preempt_count_equals(preempt_offset) && !irqs_disabled() &&
+ !is_idle_task(current)) ||
system_state != SYSTEM_RUNNING || oops_in_progress)
return;
if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
@@ -6687,6 +7071,13 @@
debug_show_held_locks(current);
if (irqs_disabled())
print_irqtrace_events(current);
+#ifdef CONFIG_DEBUG_PREEMPT
+ if (!preempt_count_equals(preempt_offset)) {
+ pr_err("Preemption disabled at:");
+ print_ip_sym(current->preempt_disable_ip);
+ pr_cont("\n");
+ }
+#endif
dump_stack();
}
EXPORT_SYMBOL(__might_sleep);
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index cfe2f268af..760e149 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -655,37 +655,45 @@
void vtime_account_system(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_gen_account_irq_exit(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
if (context_tracking_in_user())
tsk->vtime_snap_whence = VTIME_USER;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_account_user(struct task_struct *tsk)
{
cputime_t delta_cpu;
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
delta_cpu = get_vtime_delta(tsk);
tsk->vtime_snap_whence = VTIME_SYS;
account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_user_enter(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
tsk->vtime_snap_whence = VTIME_USER;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
void vtime_guest_enter(struct task_struct *tsk)
@@ -697,19 +705,23 @@
* synchronization against the reader (task_gtime())
* that can thus safely catch up with a tickless delta.
*/
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
current->flags |= PF_VCPU;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
EXPORT_SYMBOL_GPL(vtime_guest_enter);
void vtime_guest_exit(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
+ raw_spin_lock(&tsk->vtime_lock);
+ write_seqcount_begin(&tsk->vtime_seq);
__vtime_account_system(tsk);
current->flags &= ~PF_VCPU;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seq);
+ raw_spin_unlock(&tsk->vtime_lock);
}
EXPORT_SYMBOL_GPL(vtime_guest_exit);
@@ -722,24 +734,30 @@
void arch_vtime_task_switch(struct task_struct *prev)
{
- write_seqlock(&prev->vtime_seqlock);
+ raw_spin_lock(&prev->vtime_lock);
+ write_seqcount_begin(&prev->vtime_seq);
prev->vtime_snap_whence = VTIME_SLEEPING;
- write_sequnlock(&prev->vtime_seqlock);
+ write_seqcount_end(&prev->vtime_seq);
+ raw_spin_unlock(&prev->vtime_lock);
- write_seqlock(¤t->vtime_seqlock);
+ raw_spin_lock(¤t->vtime_lock);
+ write_seqcount_begin(¤t->vtime_seq);
current->vtime_snap_whence = VTIME_SYS;
current->vtime_snap = sched_clock_cpu(smp_processor_id());
- write_sequnlock(¤t->vtime_seqlock);
+ write_seqcount_end(¤t->vtime_seq);
+ raw_spin_unlock(¤t->vtime_lock);
}
void vtime_init_idle(struct task_struct *t, int cpu)
{
unsigned long flags;
- write_seqlock_irqsave(&t->vtime_seqlock, flags);
+ raw_spin_lock_irqsave(&t->vtime_lock, flags);
+ write_seqcount_begin(&t->vtime_seq);
t->vtime_snap_whence = VTIME_SYS;
t->vtime_snap = sched_clock_cpu(cpu);
- write_sequnlock_irqrestore(&t->vtime_seqlock, flags);
+ write_seqcount_end(&t->vtime_seq);
+ raw_spin_unlock_irqrestore(&t->vtime_lock, flags);
}
cputime_t task_gtime(struct task_struct *t)
@@ -748,13 +766,13 @@
cputime_t gtime;
do {
- seq = read_seqbegin(&t->vtime_seqlock);
+ seq = read_seqcount_begin(&t->vtime_seq);
gtime = t->gtime;
if (t->flags & PF_VCPU)
gtime += vtime_delta(t);
- } while (read_seqretry(&t->vtime_seqlock, seq));
+ } while (read_seqcount_retry(&t->vtime_seq, seq));
return gtime;
}
@@ -777,7 +795,7 @@
*udelta = 0;
*sdelta = 0;
- seq = read_seqbegin(&t->vtime_seqlock);
+ seq = read_seqcount_begin(&t->vtime_seq);
if (u_dst)
*u_dst = *u_src;
@@ -801,7 +819,7 @@
if (t->vtime_snap_whence == VTIME_SYS)
*sdelta = delta;
}
- } while (read_seqretry(&t->vtime_seqlock, seq));
+ } while (read_seqcount_retry(&t->vtime_seq, seq));
}
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 0efe4a2..f10a1ec 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -256,6 +256,9 @@
P(rt_throttled);
PN(rt_time);
PN(rt_runtime);
+#ifdef CONFIG_SMP
+ P(rt_nr_migratory);
+#endif
#undef PN
#undef P
@@ -585,6 +588,10 @@
#endif
P(policy);
P(prio);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ P(migrate_disable);
+#endif
+ P(nr_cpus_allowed);
#undef PN
#undef __PN
#undef P
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8986222..773c5db 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1896,7 +1896,7 @@
ideal_runtime = sched_slice(cfs_rq, curr);
delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
if (delta_exec > ideal_runtime) {
- resched_task(rq_of(cfs_rq)->curr);
+ resched_task_lazy(rq_of(cfs_rq)->curr);
/*
* The current task ran long enough, ensure it doesn't get
* re-elected due to buddy favours.
@@ -1920,7 +1920,7 @@
return;
if (delta > ideal_runtime)
- resched_task(rq_of(cfs_rq)->curr);
+ resched_task_lazy(rq_of(cfs_rq)->curr);
}
static void
@@ -2041,7 +2041,7 @@
* validating it and just reschedule.
*/
if (queued) {
- resched_task(rq_of(cfs_rq)->curr);
+ resched_task_lazy(rq_of(cfs_rq)->curr);
return;
}
/*
@@ -2231,7 +2231,7 @@
* hierarchy can be throttled
*/
if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr))
- resched_task(rq_of(cfs_rq)->curr);
+ resched_task_lazy(rq_of(cfs_rq)->curr);
}
static __always_inline
@@ -2831,7 +2831,7 @@
if (delta < 0) {
if (rq->curr == p)
- resched_task(p);
+ resched_task_lazy(p);
return;
}
@@ -3698,7 +3698,7 @@
return;
preempt:
- resched_task(curr);
+ resched_task_lazy(curr);
/*
* Only set the backward buddy when the current task is still
* on the rq. This can happen when a wakeup gets interleaved
@@ -5978,7 +5978,7 @@
* 'current' within the tree based on its new key value.
*/
swap(curr->vruntime, se->vruntime);
- resched_task(rq->curr);
+ resched_task_lazy(rq->curr);
}
se->vruntime -= cfs_rq->min_vruntime;
@@ -6003,7 +6003,7 @@
*/
if (rq->curr == p) {
if (p->prio > oldprio)
- resched_task(rq->curr);
+ resched_task_lazy(rq->curr);
} else
check_preempt_curr(rq, p, 0);
}
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 99399f8..4594051 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -50,11 +50,18 @@
*/
SCHED_FEAT(NONTASK_POWER, true)
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* Queue remote wakeups on the target CPU and process them
* using the scheduler IPI. Reduces rq->lock contention/bounces.
*/
SCHED_FEAT(TTWU_QUEUE, true)
+#else
+SCHED_FEAT(TTWU_QUEUE, false)
+# ifdef CONFIG_PREEMPT_LAZY
+SCHED_FEAT(PREEMPT_LAZY, true)
+# endif
+#endif
SCHED_FEAT(FORCE_SD_OVERLAP, false)
SCHED_FEAT(RT_RUNTIME_SHARE, true)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index ce4ec3a..209e2d3 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -43,6 +43,7 @@
hrtimer_init(&rt_b->rt_period_timer,
CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ rt_b->rt_period_timer.irqsafe = 1;
rt_b->rt_period_timer.function = sched_rt_period_timer;
}
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 2f761b7..547c136 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -915,6 +915,7 @@
#define WF_SYNC 0x01 /* waker goes to sleep after wakeup */
#define WF_FORK 0x02 /* child wakeup after fork */
#define WF_MIGRATED 0x4 /* internal use, task got migrated */
+#define WF_LOCK_SLEEPER 0x08 /* wakeup spinlock "sleeper" */
/*
* To aid in avoiding the subversion of "niceness" due to uneven distribution
@@ -1061,6 +1062,15 @@
extern void resched_task(struct task_struct *p);
extern void resched_cpu(int cpu);
+#ifdef CONFIG_PREEMPT_LAZY
+extern void resched_task_lazy(struct task_struct *tsk);
+#else
+static inline void resched_task_lazy(struct task_struct *tsk)
+{
+ resched_task(tsk);
+}
+#endif
+
extern struct rt_bandwidth def_rt_bandwidth;
extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
diff --git a/kernel/sched/work-simple.c b/kernel/sched/work-simple.c
new file mode 100644
index 0000000..c996f75
--- /dev/null
+++ b/kernel/sched/work-simple.c
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2014 BMW Car IT GmbH, Daniel Wagner daniel.wagner@bmw-carit.de
+ *
+ * Provides a framework for enqueuing callbacks from irq context
+ * PREEMPT_RT_FULL safe. The callbacks are executed in kthread context.
+ */
+
+#include <linux/wait-simple.h>
+#include <linux/work-simple.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#define SWORK_EVENT_PENDING (1 << 0)
+
+static DEFINE_MUTEX(worker_mutex);
+static struct sworker *glob_worker;
+
+struct sworker {
+ struct list_head events;
+ struct swait_head wq;
+
+ raw_spinlock_t lock;
+
+ struct task_struct *task;
+ int refs;
+};
+
+static bool swork_readable(struct sworker *worker)
+{
+ bool r;
+
+ if (kthread_should_stop())
+ return true;
+
+ raw_spin_lock_irq(&worker->lock);
+ r = !list_empty(&worker->events);
+ raw_spin_unlock_irq(&worker->lock);
+
+ return r;
+}
+
+static int swork_kthread(void *arg)
+{
+ struct sworker *worker = arg;
+
+ for (;;) {
+ swait_event_interruptible(worker->wq,
+ swork_readable(worker));
+ if (kthread_should_stop())
+ break;
+
+ raw_spin_lock_irq(&worker->lock);
+ while (!list_empty(&worker->events)) {
+ struct swork_event *sev;
+
+ sev = list_first_entry(&worker->events,
+ struct swork_event, item);
+ list_del(&sev->item);
+ raw_spin_unlock_irq(&worker->lock);
+
+ WARN_ON_ONCE(!test_and_clear_bit(SWORK_EVENT_PENDING,
+ &sev->flags));
+ sev->func(sev);
+ raw_spin_lock_irq(&worker->lock);
+ }
+ raw_spin_unlock_irq(&worker->lock);
+ }
+ return 0;
+}
+
+static struct sworker *swork_create(void)
+{
+ struct sworker *worker;
+
+ worker = kzalloc(sizeof(*worker), GFP_KERNEL);
+ if (!worker)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&worker->events);
+ raw_spin_lock_init(&worker->lock);
+ init_swait_head(&worker->wq);
+
+ worker->task = kthread_run(swork_kthread, worker, "kswork");
+ if (IS_ERR(worker->task)) {
+ kfree(worker);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return worker;
+}
+
+static void swork_destroy(struct sworker *worker)
+{
+ kthread_stop(worker->task);
+
+ WARN_ON(!list_empty(&worker->events));
+ kfree(worker);
+}
+
+/**
+ * swork_queue - queue swork
+ *
+ * Returns %false if @work was already on a queue, %true otherwise.
+ *
+ * The work is queued and processed on a random CPU
+ */
+bool swork_queue(struct swork_event *sev)
+{
+ unsigned long flags;
+
+ if (test_and_set_bit(SWORK_EVENT_PENDING, &sev->flags))
+ return false;
+
+ raw_spin_lock_irqsave(&glob_worker->lock, flags);
+ list_add_tail(&sev->item, &glob_worker->events);
+ raw_spin_unlock_irqrestore(&glob_worker->lock, flags);
+
+ swait_wake(&glob_worker->wq);
+ return true;
+}
+EXPORT_SYMBOL_GPL(swork_queue);
+
+/**
+ * swork_get - get an instance of the sworker
+ *
+ * Returns an negative error code if the initialization if the worker did not
+ * work, %0 otherwise.
+ *
+ */
+int swork_get(void)
+{
+ struct sworker *worker;
+
+ mutex_lock(&worker_mutex);
+ if (!glob_worker) {
+ worker = swork_create();
+ if (IS_ERR(worker)) {
+ mutex_unlock(&worker_mutex);
+ return -ENOMEM;
+ }
+
+ glob_worker = worker;
+ }
+
+ glob_worker->refs++;
+ mutex_unlock(&worker_mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(swork_get);
+
+/**
+ * swork_put - puts an instance of the sworker
+ *
+ * Will destroy the sworker thread. This function must not be called until all
+ * queued events have been completed.
+ */
+void swork_put(void)
+{
+ mutex_lock(&worker_mutex);
+
+ glob_worker->refs--;
+ if (glob_worker->refs > 0)
+ goto out;
+
+ swork_destroy(glob_worker);
+ glob_worker = NULL;
+out:
+ mutex_unlock(&worker_mutex);
+}
+EXPORT_SYMBOL_GPL(swork_put);
diff --git a/kernel/signal.c b/kernel/signal.c
index 1a1b0e8..00c5ab0 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -14,6 +14,7 @@
#include <linux/export.h>
#include <linux/init.h>
#include <linux/sched.h>
+#include <linux/sched/rt.h>
#include <linux/fs.h>
#include <linux/tty.h>
#include <linux/binfmts.h>
@@ -349,13 +350,45 @@
return false;
}
+#ifdef __HAVE_ARCH_CMPXCHG
+static inline struct sigqueue *get_task_cache(struct task_struct *t)
+{
+ struct sigqueue *q = t->sigqueue_cache;
+
+ if (cmpxchg(&t->sigqueue_cache, q, NULL) != q)
+ return NULL;
+ return q;
+}
+
+static inline int put_task_cache(struct task_struct *t, struct sigqueue *q)
+{
+ if (cmpxchg(&t->sigqueue_cache, NULL, q) == NULL)
+ return 0;
+ return 1;
+}
+
+#else
+
+static inline struct sigqueue *get_task_cache(struct task_struct *t)
+{
+ return NULL;
+}
+
+static inline int put_task_cache(struct task_struct *t, struct sigqueue *q)
+{
+ return 1;
+}
+
+#endif
+
/*
* allocate a new signal queue record
* - this may be called without locks if and only if t == current, otherwise an
* appropriate lock must be held to stop the target task from exiting
*/
static struct sigqueue *
-__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit)
+__sigqueue_do_alloc(int sig, struct task_struct *t, gfp_t flags,
+ int override_rlimit, int fromslab)
{
struct sigqueue *q = NULL;
struct user_struct *user;
@@ -372,7 +405,10 @@
if (override_rlimit ||
atomic_read(&user->sigpending) <=
task_rlimit(t, RLIMIT_SIGPENDING)) {
- q = kmem_cache_alloc(sigqueue_cachep, flags);
+ if (!fromslab)
+ q = get_task_cache(t);
+ if (!q)
+ q = kmem_cache_alloc(sigqueue_cachep, flags);
} else {
print_dropped_signal(sig);
}
@@ -389,6 +425,13 @@
return q;
}
+static struct sigqueue *
+__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags,
+ int override_rlimit)
+{
+ return __sigqueue_do_alloc(sig, t, flags, override_rlimit, 0);
+}
+
static void __sigqueue_free(struct sigqueue *q)
{
if (q->flags & SIGQUEUE_PREALLOC)
@@ -398,6 +441,21 @@
kmem_cache_free(sigqueue_cachep, q);
}
+static void sigqueue_free_current(struct sigqueue *q)
+{
+ struct user_struct *up;
+
+ if (q->flags & SIGQUEUE_PREALLOC)
+ return;
+
+ up = q->user;
+ if (rt_prio(current->normal_prio) && !put_task_cache(current, q)) {
+ atomic_dec(&up->sigpending);
+ free_uid(up);
+ } else
+ __sigqueue_free(q);
+}
+
void flush_sigqueue(struct sigpending *queue)
{
struct sigqueue *q;
@@ -411,6 +469,21 @@
}
/*
+ * Called from __exit_signal. Flush tsk->pending and
+ * tsk->sigqueue_cache
+ */
+void flush_task_sigqueue(struct task_struct *tsk)
+{
+ struct sigqueue *q;
+
+ flush_sigqueue(&tsk->pending);
+
+ q = get_task_cache(tsk);
+ if (q)
+ kmem_cache_free(sigqueue_cachep, q);
+}
+
+/*
* Flush all pending signals for a task.
*/
void __flush_signals(struct task_struct *t)
@@ -562,7 +635,7 @@
still_pending:
list_del_init(&first->list);
copy_siginfo(info, &first->info);
- __sigqueue_free(first);
+ sigqueue_free_current(first);
} else {
/*
* Ok, it wasn't in the queue. This must be
@@ -608,6 +681,8 @@
{
int signr;
+ WARN_ON_ONCE(tsk != current);
+
/* We only dequeue private signals from ourselves, we don't let
* signalfd steal them
*/
@@ -1230,8 +1305,8 @@
* We don't want to have recursive SIGSEGV's etc, for example,
* that is why we also clear SIGNAL_UNKILLABLE.
*/
-int
-force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
+static int
+do_force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
{
unsigned long int flags;
int ret, blocked, ignored;
@@ -1256,6 +1331,39 @@
return ret;
}
+int force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
+{
+/*
+ * On some archs, PREEMPT_RT has to delay sending a signal from a trap
+ * since it can not enable preemption, and the signal code's spin_locks
+ * turn into mutexes. Instead, it must set TIF_NOTIFY_RESUME which will
+ * send the signal on exit of the trap.
+ */
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+ if (in_atomic()) {
+ if (WARN_ON_ONCE(t != current))
+ return 0;
+ if (WARN_ON_ONCE(t->forced_info.si_signo))
+ return 0;
+
+ if (is_si_special(info)) {
+ WARN_ON_ONCE(info != SEND_SIG_PRIV);
+ t->forced_info.si_signo = sig;
+ t->forced_info.si_errno = 0;
+ t->forced_info.si_code = SI_KERNEL;
+ t->forced_info.si_pid = 0;
+ t->forced_info.si_uid = 0;
+ } else {
+ t->forced_info = *info;
+ }
+
+ set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
+ return 0;
+ }
+#endif
+ return do_force_sig_info(sig, info, t);
+}
+
/*
* Nuke all other threads in the group.
*/
@@ -1286,12 +1394,12 @@
struct sighand_struct *sighand;
for (;;) {
- local_irq_save(*flags);
+ local_irq_save_nort(*flags);
rcu_read_lock();
sighand = rcu_dereference(tsk->sighand);
if (unlikely(sighand == NULL)) {
rcu_read_unlock();
- local_irq_restore(*flags);
+ local_irq_restore_nort(*flags);
break;
}
@@ -1302,7 +1410,7 @@
}
spin_unlock(&sighand->siglock);
rcu_read_unlock();
- local_irq_restore(*flags);
+ local_irq_restore_nort(*flags);
}
return sighand;
@@ -1547,7 +1655,8 @@
*/
struct sigqueue *sigqueue_alloc(void)
{
- struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0);
+ /* Preallocated sigqueue objects always from the slabcache ! */
+ struct sigqueue *q = __sigqueue_do_alloc(-1, current, GFP_KERNEL, 0, 1);
if (q)
q->flags |= SIGQUEUE_PREALLOC;
@@ -1908,15 +2017,7 @@
if (gstop_done && ptrace_reparented(current))
do_notify_parent_cldstop(current, false, why);
- /*
- * Don't want to allow preemption here, because
- * sys_ptrace() needs this task to be inactive.
- *
- * XXX: implement read_unlock_no_resched().
- */
- preempt_disable();
read_unlock(&tasklist_lock);
- preempt_enable_no_resched();
freezable_schedule();
} else {
/*
diff --git a/kernel/softirq.c b/kernel/softirq.c
index b331c87..315b048 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -21,10 +21,12 @@
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/rcupdate.h>
+#include <linux/delay.h>
#include <linux/ftrace.h>
#include <linux/smp.h>
#include <linux/smpboot.h>
#include <linux/tick.h>
+#include <linux/locallock.h>
#define CREATE_TRACE_POINTS
#include <trace/events/irq.h>
@@ -56,12 +58,108 @@
static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp;
DEFINE_PER_CPU(struct task_struct *, ksoftirqd);
+#ifdef CONFIG_PREEMPT_RT_FULL
+#define TIMER_SOFTIRQS ((1 << TIMER_SOFTIRQ) | (1 << HRTIMER_SOFTIRQ))
+DEFINE_PER_CPU(struct task_struct *, ktimer_softirqd);
+#endif
char *softirq_to_name[NR_SOFTIRQS] = {
"HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "BLOCK_IOPOLL",
"TASKLET", "SCHED", "HRTIMER", "RCU"
};
+#ifdef CONFIG_NO_HZ_COMMON
+# ifdef CONFIG_PREEMPT_RT_FULL
+
+struct softirq_runner {
+ struct task_struct *runner[NR_SOFTIRQS];
+};
+
+static DEFINE_PER_CPU(struct softirq_runner, softirq_runners);
+
+static inline void softirq_set_runner(unsigned int sirq)
+{
+ struct softirq_runner *sr = &__get_cpu_var(softirq_runners);
+
+ sr->runner[sirq] = current;
+}
+
+static inline void softirq_clr_runner(unsigned int sirq)
+{
+ struct softirq_runner *sr = &__get_cpu_var(softirq_runners);
+
+ sr->runner[sirq] = NULL;
+}
+
+/*
+ * On preempt-rt a softirq running context might be blocked on a
+ * lock. There might be no other runnable task on this CPU because the
+ * lock owner runs on some other CPU. So we have to go into idle with
+ * the pending bit set. Therefor we need to check this otherwise we
+ * warn about false positives which confuses users and defeats the
+ * whole purpose of this test.
+ *
+ * This code is called with interrupts disabled.
+ */
+void softirq_check_pending_idle(void)
+{
+ static int rate_limit;
+ struct softirq_runner *sr = &__get_cpu_var(softirq_runners);
+ u32 warnpending;
+ int i;
+
+ if (rate_limit >= 10)
+ return;
+
+ warnpending = local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK;
+ for (i = 0; i < NR_SOFTIRQS; i++) {
+ struct task_struct *tsk = sr->runner[i];
+
+ /*
+ * The wakeup code in rtmutex.c wakes up the task
+ * _before_ it sets pi_blocked_on to NULL under
+ * tsk->pi_lock. So we need to check for both: state
+ * and pi_blocked_on.
+ */
+ if (tsk) {
+ raw_spin_lock(&tsk->pi_lock);
+ if (tsk->pi_blocked_on || tsk->state == TASK_RUNNING) {
+ /* Clear all bits pending in that task */
+ warnpending &= ~(tsk->softirqs_raised);
+ warnpending &= ~(1 << i);
+ }
+ raw_spin_unlock(&tsk->pi_lock);
+ }
+ }
+
+ if (warnpending) {
+ printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+ warnpending);
+ rate_limit++;
+ }
+}
+# else
+/*
+ * On !PREEMPT_RT we just printk rate limited:
+ */
+void softirq_check_pending_idle(void)
+{
+ static int rate_limit;
+
+ if (rate_limit < 10 &&
+ (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) {
+ printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+ local_softirq_pending());
+ rate_limit++;
+ }
+}
+# endif
+
+#else /* !CONFIG_NO_HZ_COMMON */
+static inline void softirq_set_runner(unsigned int sirq) { }
+static inline void softirq_clr_runner(unsigned int sirq) { }
+#endif
+
/*
* we cannot loop indefinitely here to avoid userspace starvation,
* but we also don't want to introduce a worst case 1/HZ latency
@@ -77,6 +175,70 @@
wake_up_process(tsk);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void wakeup_timer_softirqd(void)
+{
+ /* Interrupts are disabled: no need to stop preemption */
+ struct task_struct *tsk = __this_cpu_read(ktimer_softirqd);
+
+ if (tsk && tsk->state != TASK_RUNNING)
+ wake_up_process(tsk);
+}
+#endif
+
+static void handle_softirq(unsigned int vec_nr, int cpu, int need_rcu_bh_qs)
+{
+ struct softirq_action *h = softirq_vec + vec_nr;
+ unsigned int prev_count = preempt_count();
+
+ kstat_incr_softirqs_this_cpu(vec_nr);
+ trace_softirq_entry(vec_nr);
+ h->action(h);
+ trace_softirq_exit(vec_nr);
+
+ if (unlikely(prev_count != preempt_count())) {
+ pr_err("softirq %u %s %p preempt count leak: %08x -> %08x\n",
+ vec_nr, softirq_to_name[vec_nr], h->action,
+ prev_count, (unsigned int) preempt_count());
+ preempt_count() = prev_count;
+ }
+ if (need_rcu_bh_qs)
+ rcu_bh_qs(cpu);
+}
+
+#ifndef CONFIG_PREEMPT_RT_FULL
+static inline int ksoftirqd_softirq_pending(void)
+{
+ return local_softirq_pending();
+}
+
+static void handle_pending_softirqs(u32 pending, int cpu, int need_rcu_bh_qs)
+{
+ unsigned int vec_nr;
+
+ local_irq_enable();
+ for (vec_nr = 0; pending; vec_nr++, pending >>= 1) {
+ if (pending & 1)
+ handle_softirq(vec_nr, cpu, need_rcu_bh_qs);
+ }
+ local_irq_disable();
+}
+
+static void run_ksoftirqd(unsigned int cpu)
+{
+ local_irq_disable();
+ if (ksoftirqd_softirq_pending()) {
+ __do_softirq();
+ local_irq_enable();
+ cond_resched();
+ preempt_disable();
+ rcu_note_context_switch(cpu);
+ preempt_enable();
+ return;
+ }
+ local_irq_enable();
+}
+
/*
* preempt_count and SOFTIRQ_OFFSET usage:
* - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving
@@ -115,7 +277,7 @@
raw_local_irq_restore(flags);
if (preempt_count() == cnt)
- trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ trace_preempt_off(CALLER_ADDR0, get_lock_parent_ip());
}
#else /* !CONFIG_TRACE_IRQFLAGS */
static inline void __local_bh_disable(unsigned long ip, unsigned int cnt)
@@ -209,14 +371,51 @@
#define MAX_SOFTIRQ_TIME msecs_to_jiffies(2)
#define MAX_SOFTIRQ_RESTART 10
+#ifdef CONFIG_TRACE_IRQFLAGS
+/*
+ * Convoluted means of passing __do_softirq() a message through the various
+ * architecture execute_on_stack() bits.
+ *
+ * When we run softirqs from irq_exit() and thus on the hardirq stack we need
+ * to keep the lockdep irq context tracking as tight as possible in order to
+ * not miss-qualify lock contexts and miss possible deadlocks.
+ */
+static DEFINE_PER_CPU(int, softirq_from_hardirq);
+
+static inline void lockdep_softirq_from_hardirq(void)
+{
+ this_cpu_write(softirq_from_hardirq, 1);
+}
+
+static inline void lockdep_softirq_start(void)
+{
+ if (this_cpu_read(softirq_from_hardirq))
+ trace_hardirq_exit();
+ lockdep_softirq_enter();
+}
+
+static inline void lockdep_softirq_end(void)
+{
+ lockdep_softirq_exit();
+ if (this_cpu_read(softirq_from_hardirq)) {
+ this_cpu_write(softirq_from_hardirq, 0);
+ trace_hardirq_enter();
+ }
+}
+
+#else
+static inline void lockdep_softirq_from_hardirq(void) { }
+static inline void lockdep_softirq_start(void) { }
+static inline void lockdep_softirq_end(void) { }
+#endif
+
asmlinkage void __do_softirq(void)
{
- struct softirq_action *h;
- __u32 pending;
unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
- int cpu;
unsigned long old_flags = current->flags;
int max_restart = MAX_SOFTIRQ_RESTART;
+ __u32 pending;
+ int cpu;
/*
* Mask out PF_MEMALLOC s current task context is borrowed for the
@@ -229,43 +428,14 @@
account_irq_enter_time(current);
__local_bh_disable(_RET_IP_, SOFTIRQ_OFFSET);
- lockdep_softirq_enter();
+ lockdep_softirq_start();
cpu = smp_processor_id();
restart:
/* Reset the pending bitmask before enabling irqs */
set_softirq_pending(0);
- local_irq_enable();
-
- h = softirq_vec;
-
- do {
- if (pending & 1) {
- unsigned int vec_nr = h - softirq_vec;
- int prev_count = preempt_count();
-
- kstat_incr_softirqs_this_cpu(vec_nr);
-
- trace_softirq_entry(vec_nr);
- h->action(h);
- trace_softirq_exit(vec_nr);
- if (unlikely(prev_count != preempt_count())) {
- printk(KERN_ERR "huh, entered softirq %u %s %p"
- "with preempt_count %08x,"
- " exited with %08x?\n", vec_nr,
- softirq_to_name[vec_nr], h->action,
- prev_count, preempt_count());
- preempt_count() = prev_count;
- }
-
- rcu_bh_qs(cpu);
- }
- h++;
- pending >>= 1;
- } while (pending);
-
- local_irq_disable();
+ handle_pending_softirqs(pending, cpu, 1);
pending = local_softirq_pending();
if (pending) {
@@ -276,8 +446,7 @@
wakeup_softirqd();
}
- lockdep_softirq_exit();
-
+ lockdep_softirq_end();
account_irq_exit_time(current);
__local_bh_enable(SOFTIRQ_OFFSET);
tsk_restore_flags(current, old_flags, PF_MEMALLOC);
@@ -306,6 +475,315 @@
#endif
/*
+ * This function must run with irqs disabled!
+ */
+void raise_softirq_irqoff(unsigned int nr)
+{
+ __raise_softirq_irqoff(nr);
+
+ /*
+ * If we're in an interrupt or softirq, we're done
+ * (this also catches softirq-disabled code). We will
+ * actually run the softirq once we return from
+ * the irq or softirq.
+ *
+ * Otherwise we wake up ksoftirqd to make sure we
+ * schedule the softirq soon.
+ */
+ if (!in_interrupt())
+ wakeup_softirqd();
+}
+
+void __raise_softirq_irqoff(unsigned int nr)
+{
+ trace_softirq_raise(nr);
+ or_softirq_pending(1UL << nr);
+}
+
+static inline void local_bh_disable_nort(void) { local_bh_disable(); }
+static inline void _local_bh_enable_nort(void) { _local_bh_enable(); }
+static void ksoftirqd_set_sched_params(unsigned int cpu) { }
+
+#else /* !PREEMPT_RT_FULL */
+
+/*
+ * On RT we serialize softirq execution with a cpu local lock per softirq
+ */
+static DEFINE_PER_CPU(struct local_irq_lock [NR_SOFTIRQS], local_softirq_locks);
+
+void __init softirq_early_init(void)
+{
+ int i;
+
+ for (i = 0; i < NR_SOFTIRQS; i++)
+ local_irq_lock_init(local_softirq_locks[i]);
+}
+
+static void lock_softirq(int which)
+{
+ local_lock(local_softirq_locks[which]);
+}
+
+static void unlock_softirq(int which)
+{
+ local_unlock(local_softirq_locks[which]);
+}
+
+static void do_single_softirq(int which, int need_rcu_bh_qs)
+{
+ unsigned long old_flags = current->flags;
+
+ current->flags &= ~PF_MEMALLOC;
+ vtime_account_irq_enter(current);
+ current->flags |= PF_IN_SOFTIRQ;
+ lockdep_softirq_enter();
+ local_irq_enable();
+ handle_softirq(which, smp_processor_id(), need_rcu_bh_qs);
+ local_irq_disable();
+ lockdep_softirq_exit();
+ current->flags &= ~PF_IN_SOFTIRQ;
+ vtime_account_irq_enter(current);
+ tsk_restore_flags(current, old_flags, PF_MEMALLOC);
+}
+
+/*
+ * Called with interrupts disabled. Process softirqs which were raised
+ * in current context (or on behalf of ksoftirqd).
+ */
+static void do_current_softirqs(int need_rcu_bh_qs)
+{
+ while (current->softirqs_raised) {
+ int i = __ffs(current->softirqs_raised);
+ unsigned int pending, mask = (1U << i);
+
+ current->softirqs_raised &= ~mask;
+ local_irq_enable();
+
+ /*
+ * If the lock is contended, we boost the owner to
+ * process the softirq or leave the critical section
+ * now.
+ */
+ lock_softirq(i);
+ local_irq_disable();
+ softirq_set_runner(i);
+ /*
+ * Check with the local_softirq_pending() bits,
+ * whether we need to process this still or if someone
+ * else took care of it.
+ */
+ pending = local_softirq_pending();
+ if (pending & mask) {
+ set_softirq_pending(pending & ~mask);
+ do_single_softirq(i, need_rcu_bh_qs);
+ }
+ softirq_clr_runner(i);
+ WARN_ON(current->softirq_nestcnt != 1);
+ local_irq_enable();
+ unlock_softirq(i);
+ local_irq_disable();
+ }
+}
+
+void local_bh_disable(void)
+{
+ if (++current->softirq_nestcnt == 1)
+ migrate_disable();
+}
+EXPORT_SYMBOL(local_bh_disable);
+
+void local_bh_enable(void)
+{
+ if (WARN_ON(current->softirq_nestcnt == 0))
+ return;
+
+ local_irq_disable();
+ if (current->softirq_nestcnt == 1 && current->softirqs_raised)
+ do_current_softirqs(1);
+ local_irq_enable();
+
+ if (--current->softirq_nestcnt == 0)
+ migrate_enable();
+}
+EXPORT_SYMBOL(local_bh_enable);
+
+void local_bh_enable_ip(unsigned long ip)
+{
+ local_bh_enable();
+}
+EXPORT_SYMBOL(local_bh_enable_ip);
+
+void _local_bh_enable(void)
+{
+ if (WARN_ON(current->softirq_nestcnt == 0))
+ return;
+ if (--current->softirq_nestcnt == 0)
+ migrate_enable();
+}
+EXPORT_SYMBOL(_local_bh_enable);
+
+int in_serving_softirq(void)
+{
+ return current->flags & PF_IN_SOFTIRQ;
+}
+EXPORT_SYMBOL(in_serving_softirq);
+
+/* Called with preemption disabled */
+static void run_ksoftirqd(unsigned int cpu)
+{
+ local_irq_disable();
+ current->softirq_nestcnt++;
+ do_current_softirqs(1);
+ current->softirq_nestcnt--;
+ local_irq_enable();
+ rcu_note_context_switch(cpu);
+}
+
+/*
+ * Called from netif_rx_ni(). Preemption enabled, but migration
+ * disabled. So the cpu can't go away under us.
+ */
+void thread_do_softirq(void)
+{
+ if (!in_serving_softirq() && current->softirqs_raised) {
+ current->softirq_nestcnt++;
+ do_current_softirqs(0);
+ current->softirq_nestcnt--;
+ }
+}
+
+static void do_raise_softirq_irqoff(unsigned int nr)
+{
+ unsigned int mask;
+
+ mask = 1UL << nr;
+
+ trace_softirq_raise(nr);
+ or_softirq_pending(mask);
+
+ /*
+ * If we are not in a hard interrupt and inside a bh disabled
+ * region, we simply raise the flag on current. local_bh_enable()
+ * will make sure that the softirq is executed. Otherwise we
+ * delegate it to ksoftirqd.
+ */
+ if (!in_irq() && current->softirq_nestcnt)
+ current->softirqs_raised |= mask;
+ else if (!__this_cpu_read(ksoftirqd) || !__this_cpu_read(ktimer_softirqd))
+ return;
+
+ if (mask & TIMER_SOFTIRQS)
+ __this_cpu_read(ktimer_softirqd)->softirqs_raised |= mask;
+ else
+ __this_cpu_read(ksoftirqd)->softirqs_raised |= mask;
+}
+
+static void wakeup_proper_softirq(unsigned int nr)
+{
+ if ((1UL << nr) & TIMER_SOFTIRQS)
+ wakeup_timer_softirqd();
+ else
+ wakeup_softirqd();
+}
+
+void __raise_softirq_irqoff(unsigned int nr)
+{
+ do_raise_softirq_irqoff(nr);
+ if (!in_irq() && !current->softirq_nestcnt)
+ wakeup_proper_softirq(nr);
+}
+
+/*
+ * Same as __raise_softirq_irqoff() but will process them in ksoftirqd
+ */
+void __raise_softirq_irqoff_ksoft(unsigned int nr)
+{
+ unsigned int mask;
+
+ if (WARN_ON_ONCE(!__this_cpu_read(ksoftirqd) ||
+ !__this_cpu_read(ktimer_softirqd)))
+ return;
+ mask = 1UL << nr;
+
+ trace_softirq_raise(nr);
+ or_softirq_pending(mask);
+ if (mask & TIMER_SOFTIRQS)
+ __this_cpu_read(ktimer_softirqd)->softirqs_raised |= mask;
+ else
+ __this_cpu_read(ksoftirqd)->softirqs_raised |= mask;
+ wakeup_proper_softirq(nr);
+}
+
+/*
+ * This function must run with irqs disabled!
+ */
+void raise_softirq_irqoff(unsigned int nr)
+{
+ do_raise_softirq_irqoff(nr);
+
+ /*
+ * If we're in an hard interrupt we let irq return code deal
+ * with the wakeup of ksoftirqd.
+ */
+ if (in_irq())
+ return;
+
+ /*
+ * If we are in thread context but outside of a bh disabled
+ * region, we need to wake ksoftirqd as well.
+ *
+ * CHECKME: Some of the places which do that could be wrapped
+ * into local_bh_disable/enable pairs. Though it's unclear
+ * whether this is worth the effort. To find those places just
+ * raise a WARN() if the condition is met.
+ */
+ if (!current->softirq_nestcnt)
+ wakeup_softirqd();
+}
+
+static inline int ksoftirqd_softirq_pending(void)
+{
+ return current->softirqs_raised;
+}
+
+static inline void local_bh_disable_nort(void) { }
+static inline void _local_bh_enable_nort(void) { }
+
+static inline void ksoftirqd_set_sched_params(unsigned int cpu)
+{
+ /* Take over all but timer pending softirqs when starting */
+ local_irq_disable();
+ current->softirqs_raised = local_softirq_pending() & ~TIMER_SOFTIRQS;
+ local_irq_enable();
+}
+
+static inline void ktimer_softirqd_set_sched_params(unsigned int cpu)
+{
+ struct sched_param param = { .sched_priority = 1 };
+
+ sched_setscheduler(current, SCHED_FIFO, ¶m);
+
+ /* Take over timer pending softirqs when starting */
+ local_irq_disable();
+ current->softirqs_raised = local_softirq_pending() & TIMER_SOFTIRQS;
+ local_irq_enable();
+}
+
+static inline void ktimer_softirqd_clr_sched_params(unsigned int cpu,
+ bool online)
+{
+ struct sched_param param = { .sched_priority = 0 };
+
+ sched_setscheduler(current, SCHED_NORMAL, ¶m);
+}
+
+static int ktimer_softirqd_should_run(unsigned int cpu)
+{
+ return current->softirqs_raised;
+}
+
+#endif /* PREEMPT_RT_FULL */
+/*
* Enter an interrupt context.
*/
void irq_enter(void)
@@ -318,9 +796,9 @@
* Prevent raise_softirq from needlessly waking up ksoftirqd
* here, as softirq will be serviced on return from interrupt.
*/
- local_bh_disable();
+ local_bh_disable_nort();
tick_check_idle(cpu);
- _local_bh_enable();
+ _local_bh_enable_nort();
}
__irq_enter();
@@ -328,7 +806,9 @@
static inline void invoke_softirq(void)
{
+#ifndef CONFIG_PREEMPT_RT_FULL
if (!force_irqthreads) {
+ lockdep_softirq_from_hardirq();
/*
* We can safely execute softirq on the current stack if
* it is the irq stack, because it should be near empty
@@ -341,6 +821,18 @@
} else {
wakeup_softirqd();
}
+#else /* PREEMPT_RT_FULL */
+ unsigned long flags;
+
+ local_irq_save(flags);
+ if (__this_cpu_read(ksoftirqd) &&
+ __this_cpu_read(ksoftirqd)->softirqs_raised)
+ wakeup_softirqd();
+ if (__this_cpu_read(ktimer_softirqd) &&
+ __this_cpu_read(ktimer_softirqd)->softirqs_raised)
+ wakeup_timer_softirqd();
+ local_irq_restore(flags);
+#endif
}
static inline void tick_irq_exit(void)
@@ -368,33 +860,13 @@
#endif
account_irq_exit_time(current);
- trace_hardirq_exit();
sub_preempt_count(HARDIRQ_OFFSET);
if (!in_interrupt() && local_softirq_pending())
invoke_softirq();
tick_irq_exit();
rcu_irq_exit();
-}
-
-/*
- * This function must run with irqs disabled!
- */
-inline void raise_softirq_irqoff(unsigned int nr)
-{
- __raise_softirq_irqoff(nr);
-
- /*
- * If we're in an interrupt or softirq, we're done
- * (this also catches softirq-disabled code). We will
- * actually run the softirq once we return from
- * the irq or softirq.
- *
- * Otherwise we wake up ksoftirqd to make sure we
- * schedule the softirq soon.
- */
- if (!in_interrupt())
- wakeup_softirqd();
+ trace_hardirq_exit(); /* must be last! */
}
void raise_softirq(unsigned int nr)
@@ -406,12 +878,6 @@
local_irq_restore(flags);
}
-void __raise_softirq_irqoff(unsigned int nr)
-{
- trace_softirq_raise(nr);
- or_softirq_pending(1UL << nr);
-}
-
void open_softirq(int nr, void (*action)(struct softirq_action *))
{
softirq_vec[nr].action = action;
@@ -429,15 +895,45 @@
static DEFINE_PER_CPU(struct tasklet_head, tasklet_vec);
static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec);
+static void inline
+__tasklet_common_schedule(struct tasklet_struct *t, struct tasklet_head *head, unsigned int nr)
+{
+ if (tasklet_trylock(t)) {
+again:
+ /* We may have been preempted before tasklet_trylock
+ * and __tasklet_action may have already run.
+ * So double check the sched bit while the takslet
+ * is locked before adding it to the list.
+ */
+ if (test_bit(TASKLET_STATE_SCHED, &t->state)) {
+ t->next = NULL;
+ *head->tail = t;
+ head->tail = &(t->next);
+ raise_softirq_irqoff(nr);
+ tasklet_unlock(t);
+ } else {
+ /* This is subtle. If we hit the corner case above
+ * It is possible that we get preempted right here,
+ * and another task has successfully called
+ * tasklet_schedule(), then this function, and
+ * failed on the trylock. Thus we must be sure
+ * before releasing the tasklet lock, that the
+ * SCHED_BIT is clear. Otherwise the tasklet
+ * may get its SCHED_BIT set, but not added to the
+ * list
+ */
+ if (!tasklet_tryunlock(t))
+ goto again;
+ }
+ }
+}
+
void __tasklet_schedule(struct tasklet_struct *t)
{
unsigned long flags;
local_irq_save(flags);
- t->next = NULL;
- *__this_cpu_read(tasklet_vec.tail) = t;
- __this_cpu_write(tasklet_vec.tail, &(t->next));
- raise_softirq_irqoff(TASKLET_SOFTIRQ);
+ __tasklet_common_schedule(t, &__get_cpu_var(tasklet_vec), TASKLET_SOFTIRQ);
local_irq_restore(flags);
}
@@ -448,10 +944,7 @@
unsigned long flags;
local_irq_save(flags);
- t->next = NULL;
- *__this_cpu_read(tasklet_hi_vec.tail) = t;
- __this_cpu_write(tasklet_hi_vec.tail, &(t->next));
- raise_softirq_irqoff(HI_SOFTIRQ);
+ __tasklet_common_schedule(t, &__get_cpu_var(tasklet_hi_vec), HI_SOFTIRQ);
local_irq_restore(flags);
}
@@ -459,50 +952,119 @@
void __tasklet_hi_schedule_first(struct tasklet_struct *t)
{
- BUG_ON(!irqs_disabled());
-
- t->next = __this_cpu_read(tasklet_hi_vec.head);
- __this_cpu_write(tasklet_hi_vec.head, t);
- __raise_softirq_irqoff(HI_SOFTIRQ);
+ __tasklet_hi_schedule(t);
}
EXPORT_SYMBOL(__tasklet_hi_schedule_first);
-static void tasklet_action(struct softirq_action *a)
+void tasklet_enable(struct tasklet_struct *t)
{
- struct tasklet_struct *list;
+ if (!atomic_dec_and_test(&t->count))
+ return;
+ if (test_and_clear_bit(TASKLET_STATE_PENDING, &t->state))
+ tasklet_schedule(t);
+}
- local_irq_disable();
- list = __this_cpu_read(tasklet_vec.head);
- __this_cpu_write(tasklet_vec.head, NULL);
- __this_cpu_write(tasklet_vec.tail, &__get_cpu_var(tasklet_vec).head);
- local_irq_enable();
+EXPORT_SYMBOL(tasklet_enable);
+
+void tasklet_hi_enable(struct tasklet_struct *t)
+{
+ if (!atomic_dec_and_test(&t->count))
+ return;
+ if (test_and_clear_bit(TASKLET_STATE_PENDING, &t->state))
+ tasklet_hi_schedule(t);
+}
+
+EXPORT_SYMBOL(tasklet_hi_enable);
+
+static void
+__tasklet_action(struct softirq_action *a, struct tasklet_struct *list)
+{
+ int loops = 1000000;
while (list) {
struct tasklet_struct *t = list;
list = list->next;
- if (tasklet_trylock(t)) {
- if (!atomic_read(&t->count)) {
- if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
- BUG();
- t->func(t->data);
- tasklet_unlock(t);
- continue;
- }
- tasklet_unlock(t);
+ /*
+ * Should always succeed - after a tasklist got on the
+ * list (after getting the SCHED bit set from 0 to 1),
+ * nothing but the tasklet softirq it got queued to can
+ * lock it:
+ */
+ if (!tasklet_trylock(t)) {
+ WARN_ON(1);
+ continue;
}
- local_irq_disable();
t->next = NULL;
- *__this_cpu_read(tasklet_vec.tail) = t;
- __this_cpu_write(tasklet_vec.tail, &(t->next));
- __raise_softirq_irqoff(TASKLET_SOFTIRQ);
- local_irq_enable();
+
+ /*
+ * If we cannot handle the tasklet because it's disabled,
+ * mark it as pending. tasklet_enable() will later
+ * re-schedule the tasklet.
+ */
+ if (unlikely(atomic_read(&t->count))) {
+out_disabled:
+ /* implicit unlock: */
+ wmb();
+ t->state = TASKLET_STATEF_PENDING;
+ continue;
+ }
+
+ /*
+ * After this point on the tasklet might be rescheduled
+ * on another CPU, but it can only be added to another
+ * CPU's tasklet list if we unlock the tasklet (which we
+ * dont do yet).
+ */
+ if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
+ WARN_ON(1);
+
+again:
+ t->func(t->data);
+
+ /*
+ * Try to unlock the tasklet. We must use cmpxchg, because
+ * another CPU might have scheduled or disabled the tasklet.
+ * We only allow the STATE_RUN -> 0 transition here.
+ */
+ while (!tasklet_tryunlock(t)) {
+ /*
+ * If it got disabled meanwhile, bail out:
+ */
+ if (atomic_read(&t->count))
+ goto out_disabled;
+ /*
+ * If it got scheduled meanwhile, re-execute
+ * the tasklet function:
+ */
+ if (test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
+ goto again;
+ if (!--loops) {
+ printk("hm, tasklet state: %08lx\n", t->state);
+ WARN_ON(1);
+ tasklet_unlock(t);
+ break;
+ }
+ }
}
}
+static void tasklet_action(struct softirq_action *a)
+{
+ struct tasklet_struct *list;
+
+ local_irq_disable();
+ list = __get_cpu_var(tasklet_vec).head;
+ __get_cpu_var(tasklet_vec).head = NULL;
+ __get_cpu_var(tasklet_vec).tail = &__get_cpu_var(tasklet_vec).head;
+ local_irq_enable();
+
+ __tasklet_action(a, list);
+}
+
static void tasklet_hi_action(struct softirq_action *a)
{
struct tasklet_struct *list;
@@ -513,29 +1075,7 @@
__this_cpu_write(tasklet_hi_vec.tail, &__get_cpu_var(tasklet_hi_vec).head);
local_irq_enable();
- while (list) {
- struct tasklet_struct *t = list;
-
- list = list->next;
-
- if (tasklet_trylock(t)) {
- if (!atomic_read(&t->count)) {
- if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
- BUG();
- t->func(t->data);
- tasklet_unlock(t);
- continue;
- }
- tasklet_unlock(t);
- }
-
- local_irq_disable();
- t->next = NULL;
- *__this_cpu_read(tasklet_hi_vec.tail) = t;
- __this_cpu_write(tasklet_hi_vec.tail, &(t->next));
- __raise_softirq_irqoff(HI_SOFTIRQ);
- local_irq_enable();
- }
+ __tasklet_action(a, list);
}
@@ -558,7 +1098,7 @@
while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) {
do {
- yield();
+ msleep(1);
} while (test_bit(TASKLET_STATE_SCHED, &t->state));
}
tasklet_unlock_wait(t);
@@ -762,26 +1302,26 @@
open_softirq(HI_SOFTIRQ, tasklet_hi_action);
}
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
+void tasklet_unlock_wait(struct tasklet_struct *t)
+{
+ while (test_bit(TASKLET_STATE_RUN, &(t)->state)) {
+ /*
+ * Hack for now to avoid this busy-loop:
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+ msleep(1);
+#else
+ barrier();
+#endif
+ }
+}
+EXPORT_SYMBOL(tasklet_unlock_wait);
+#endif
+
static int ksoftirqd_should_run(unsigned int cpu)
{
- return local_softirq_pending();
-}
-
-static void run_ksoftirqd(unsigned int cpu)
-{
- local_irq_disable();
- if (local_softirq_pending()) {
- __do_softirq();
- local_irq_enable();
- cond_resched();
-
- preempt_disable();
- rcu_note_context_switch(cpu);
- preempt_enable();
-
- return;
- }
- local_irq_enable();
+ return ksoftirqd_softirq_pending();
}
#ifdef CONFIG_HOTPLUG_CPU
@@ -864,16 +1404,31 @@
static struct smp_hotplug_thread softirq_threads = {
.store = &ksoftirqd,
+ .setup = ksoftirqd_set_sched_params,
.thread_should_run = ksoftirqd_should_run,
.thread_fn = run_ksoftirqd,
.thread_comm = "ksoftirqd/%u",
};
+#ifdef CONFIG_PREEMPT_RT_FULL
+static struct smp_hotplug_thread softirq_timer_threads = {
+ .store = &ktimer_softirqd,
+ .setup = ktimer_softirqd_set_sched_params,
+ .cleanup = ktimer_softirqd_clr_sched_params,
+ .thread_should_run = ktimer_softirqd_should_run,
+ .thread_fn = run_ksoftirqd,
+ .thread_comm = "ktimersoftd/%u",
+};
+#endif
+
static __init int spawn_ksoftirqd(void)
{
register_cpu_notifier(&cpu_nfb);
BUG_ON(smpboot_register_percpu_thread(&softirq_threads));
+#ifdef CONFIG_PREEMPT_RT_FULL
+ BUG_ON(smpboot_register_percpu_thread(&softirq_timer_threads));
+#endif
return 0;
}
diff --git a/kernel/spinlock.c b/kernel/spinlock.c
index 4b082b5..5c76166 100644
--- a/kernel/spinlock.c
+++ b/kernel/spinlock.c
@@ -124,8 +124,11 @@
* __[spin|read|write]_lock_bh()
*/
BUILD_LOCK_OPS(spin, raw_spinlock);
+
+#ifndef CONFIG_PREEMPT_RT_FULL
BUILD_LOCK_OPS(read, rwlock);
BUILD_LOCK_OPS(write, rwlock);
+#endif
#endif
@@ -209,6 +212,8 @@
EXPORT_SYMBOL(_raw_spin_unlock_bh);
#endif
+#ifndef CONFIG_PREEMPT_RT_FULL
+
#ifndef CONFIG_INLINE_READ_TRYLOCK
int __lockfunc _raw_read_trylock(rwlock_t *lock)
{
@@ -353,6 +358,8 @@
EXPORT_SYMBOL(_raw_write_unlock_bh);
#endif
+#endif /* !PREEMPT_RT_FULL */
+
#ifdef CONFIG_DEBUG_LOCK_ALLOC
void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass)
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index c09f295..652fea4 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -34,7 +34,7 @@
/* the actual stopper, one per every possible cpu, enabled on online cpus */
struct cpu_stopper {
- spinlock_t lock;
+ raw_spinlock_t lock;
bool enabled; /* is this stopper enabled? */
struct list_head works; /* list of pending works */
};
@@ -69,7 +69,7 @@
unsigned long flags;
- spin_lock_irqsave(&stopper->lock, flags);
+ raw_spin_lock_irqsave(&stopper->lock, flags);
if (stopper->enabled) {
list_add_tail(&work->list, &stopper->works);
@@ -77,7 +77,7 @@
} else
cpu_stop_signal_done(work->done, false);
- spin_unlock_irqrestore(&stopper->lock, flags);
+ raw_spin_unlock_irqrestore(&stopper->lock, flags);
}
/**
@@ -137,11 +137,12 @@
/* static data for stop_cpus */
static DEFINE_MUTEX(stop_cpus_mutex);
+static DEFINE_MUTEX(stopper_lock);
static DEFINE_PER_CPU(struct cpu_stop_work, stop_cpus_work);
static void queue_stop_cpus_work(const struct cpumask *cpumask,
cpu_stop_fn_t fn, void *arg,
- struct cpu_stop_done *done)
+ struct cpu_stop_done *done, bool inactive)
{
struct cpu_stop_work *work;
unsigned int cpu;
@@ -155,14 +156,18 @@
}
/*
- * Disable preemption while queueing to avoid getting
- * preempted by a stopper which might wait for other stoppers
- * to enter @fn which can lead to deadlock.
+ * Make sure that all work is queued on all cpus before we
+ * any of the cpus can execute it.
*/
- preempt_disable();
+ if (!inactive) {
+ mutex_lock(&stopper_lock);
+ } else {
+ while (!mutex_trylock(&stopper_lock))
+ cpu_relax();
+ }
for_each_cpu(cpu, cpumask)
cpu_stop_queue_work(cpu, &per_cpu(stop_cpus_work, cpu));
- preempt_enable();
+ mutex_unlock(&stopper_lock);
}
static int __stop_cpus(const struct cpumask *cpumask,
@@ -171,7 +176,7 @@
struct cpu_stop_done done;
cpu_stop_init_done(&done, cpumask_weight(cpumask));
- queue_stop_cpus_work(cpumask, fn, arg, &done);
+ queue_stop_cpus_work(cpumask, fn, arg, &done, false);
wait_for_completion(&done.completion);
return done.executed ? done.ret : -ENOENT;
}
@@ -251,9 +256,9 @@
unsigned long flags;
int run;
- spin_lock_irqsave(&stopper->lock, flags);
+ raw_spin_lock_irqsave(&stopper->lock, flags);
run = !list_empty(&stopper->works);
- spin_unlock_irqrestore(&stopper->lock, flags);
+ raw_spin_unlock_irqrestore(&stopper->lock, flags);
return run;
}
@@ -265,13 +270,13 @@
repeat:
work = NULL;
- spin_lock_irq(&stopper->lock);
+ raw_spin_lock_irq(&stopper->lock);
if (!list_empty(&stopper->works)) {
work = list_first_entry(&stopper->works,
struct cpu_stop_work, list);
list_del_init(&work->list);
}
- spin_unlock_irq(&stopper->lock);
+ raw_spin_unlock_irq(&stopper->lock);
if (work) {
cpu_stop_fn_t fn = work->fn;
@@ -279,6 +284,16 @@
struct cpu_stop_done *done = work->done;
char ksym_buf[KSYM_NAME_LEN] __maybe_unused;
+ /*
+ * Wait until the stopper finished scheduling on all
+ * cpus
+ */
+ mutex_lock(&stopper_lock);
+ /*
+ * Let other cpu threads continue as well
+ */
+ mutex_unlock(&stopper_lock);
+
/* cpu stop callbacks are not allowed to sleep */
preempt_disable();
@@ -312,20 +327,20 @@
unsigned long flags;
/* drain remaining works */
- spin_lock_irqsave(&stopper->lock, flags);
+ raw_spin_lock_irqsave(&stopper->lock, flags);
list_for_each_entry(work, &stopper->works, list)
cpu_stop_signal_done(work->done, false);
stopper->enabled = false;
- spin_unlock_irqrestore(&stopper->lock, flags);
+ raw_spin_unlock_irqrestore(&stopper->lock, flags);
}
static void cpu_stop_unpark(unsigned int cpu)
{
struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
- spin_lock_irq(&stopper->lock);
+ raw_spin_lock_irq(&stopper->lock);
stopper->enabled = true;
- spin_unlock_irq(&stopper->lock);
+ raw_spin_unlock_irq(&stopper->lock);
}
static struct smp_hotplug_thread cpu_stop_threads = {
@@ -347,7 +362,7 @@
for_each_possible_cpu(cpu) {
struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
- spin_lock_init(&stopper->lock);
+ raw_spin_lock_init(&stopper->lock);
INIT_LIST_HEAD(&stopper->works);
}
@@ -530,7 +545,7 @@
set_state(&smdata, STOPMACHINE_PREPARE);
cpu_stop_init_done(&done, num_active_cpus());
queue_stop_cpus_work(cpu_active_mask, stop_machine_cpu_stop, &smdata,
- &done);
+ &done, true);
ret = stop_machine_cpu_stop(&smdata);
/* Busy wait for completion. */
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index a6a5bf5..23d7203 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -73,7 +73,8 @@
.shift = JIFFIES_SHIFT,
};
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(jiffies_lock);
+__cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(jiffies_lock);
+__cacheline_aligned_in_smp seqcount_t jiffies_seq;
#if (BITS_PER_LONG < 64)
u64 get_jiffies_64(void)
@@ -82,9 +83,9 @@
u64 ret;
do {
- seq = read_seqbegin(&jiffies_lock);
+ seq = read_seqcount_begin(&jiffies_seq);
ret = jiffies_64;
- } while (read_seqretry(&jiffies_lock, seq));
+ } while (read_seqcount_retry(&jiffies_seq, seq));
return ret;
}
EXPORT_SYMBOL(get_jiffies_64);
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 6211d5d..0cc6c9f 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -10,6 +10,7 @@
#include <linux/workqueue.h>
#include <linux/hrtimer.h>
#include <linux/jiffies.h>
+#include <linux/kthread.h>
#include <linux/math64.h>
#include <linux/timex.h>
#include <linux/time.h>
@@ -517,10 +518,49 @@
schedule_delayed_work(&sync_cmos_work, timespec_to_jiffies(&next));
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * RT can not call schedule_delayed_work from real interrupt context.
+ * Need to make a thread to do the real work.
+ */
+static struct task_struct *cmos_delay_thread;
+static bool do_cmos_delay;
+
+static int run_cmos_delay(void *ignore)
+{
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (do_cmos_delay) {
+ do_cmos_delay = false;
+ schedule_delayed_work(&sync_cmos_work, 0);
+ }
+ schedule();
+ }
+ __set_current_state(TASK_RUNNING);
+ return 0;
+}
+
+void ntp_notify_cmos_timer(void)
+{
+ do_cmos_delay = true;
+ /* Make visible before waking up process */
+ smp_wmb();
+ wake_up_process(cmos_delay_thread);
+}
+
+static __init int create_cmos_delay_thread(void)
+{
+ cmos_delay_thread = kthread_run(run_cmos_delay, NULL, "kcmosdelayd");
+ BUG_ON(!cmos_delay_thread);
+ return 0;
+}
+early_initcall(create_cmos_delay_thread);
+#else
void ntp_notify_cmos_timer(void)
{
schedule_delayed_work(&sync_cmos_work, 0);
}
+#endif /* CONFIG_PREEMPT_RT_FULL */
#else
void ntp_notify_cmos_timer(void) { }
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 271ce26..07e90b4 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -63,13 +63,15 @@
static void tick_periodic(int cpu)
{
if (tick_do_timer_cpu == cpu) {
- write_seqlock(&jiffies_lock);
+ raw_spin_lock(&jiffies_lock);
+ write_seqcount_begin(&jiffies_seq);
/* Keep track of the next tick event */
tick_next_period = ktime_add(tick_next_period, tick_period);
do_timer(1);
- write_sequnlock(&jiffies_lock);
+ write_seqcount_end(&jiffies_seq);
+ raw_spin_unlock(&jiffies_lock);
}
update_process_times(user_mode(get_irq_regs()));
@@ -130,9 +132,9 @@
ktime_t next;
do {
- seq = read_seqbegin(&jiffies_lock);
+ seq = read_seqcount_begin(&jiffies_seq);
next = tick_next_period;
- } while (read_seqretry(&jiffies_lock, seq));
+ } while (read_seqcount_retry(&jiffies_seq, seq));
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index bc906ca..7e5e7f8 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -4,7 +4,8 @@
#include <linux/hrtimer.h>
#include <linux/tick.h>
-extern seqlock_t jiffies_lock;
+extern raw_spinlock_t jiffies_lock;
+extern seqcount_t jiffies_seq;
#define CS_NAME_LEN 32
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 67673ca..3238cfb 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -62,7 +62,8 @@
return;
/* Reevalute with jiffies_lock held */
- write_seqlock(&jiffies_lock);
+ raw_spin_lock(&jiffies_lock);
+ write_seqcount_begin(&jiffies_seq);
delta = ktime_sub(now, last_jiffies_update);
if (delta.tv64 >= tick_period.tv64) {
@@ -85,7 +86,8 @@
/* Keep the tick_next_period variable up to date */
tick_next_period = ktime_add(last_jiffies_update, tick_period);
}
- write_sequnlock(&jiffies_lock);
+ write_seqcount_end(&jiffies_seq);
+ raw_spin_unlock(&jiffies_lock);
}
/*
@@ -95,12 +97,14 @@
{
ktime_t period;
- write_seqlock(&jiffies_lock);
+ raw_spin_lock(&jiffies_lock);
+ write_seqcount_begin(&jiffies_seq);
/* Did we start the jiffies update yet ? */
if (last_jiffies_update.tv64 == 0)
last_jiffies_update = tick_next_period;
period = last_jiffies_update;
- write_sequnlock(&jiffies_lock);
+ write_seqcount_end(&jiffies_seq);
+ raw_spin_unlock(&jiffies_lock);
return period;
}
@@ -171,6 +175,11 @@
return false;
}
+ if (!arch_irq_work_has_interrupt()) {
+ trace_tick_stop(0, "missing irq work interrupt\n");
+ return false;
+ }
+
/* sched_clock_tick() needs us? */
#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
/*
@@ -212,11 +221,17 @@
static void nohz_full_kick_work_func(struct irq_work *work)
{
+ unsigned long flags;
+
+ /* ksoftirqd processes sirqs with interrupts enabled */
+ local_irq_save(flags);
__tick_nohz_full_check();
+ local_irq_restore(flags);
}
static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
.func = nohz_full_kick_work_func,
+ .flags = IRQ_WORK_HARD_IRQ,
};
/*
@@ -538,11 +553,11 @@
/* Read jiffies and the time when jiffies were updated last */
do {
- seq = read_seqbegin(&jiffies_lock);
+ seq = read_seqcount_begin(&jiffies_seq);
last_update = last_jiffies_update;
last_jiffies = jiffies;
time_delta = timekeeping_max_deferment();
- } while (read_seqretry(&jiffies_lock, seq));
+ } while (read_seqcount_retry(&jiffies_seq, seq));
if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) ||
arch_needs_cpu(cpu) || irq_work_needs_cpu()) {
@@ -720,14 +735,7 @@
return false;
if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
- static int ratelimit;
-
- if (ratelimit < 10 &&
- (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) {
- pr_warn("NOHZ: local_softirq_pending %02x\n",
- (unsigned int) local_softirq_pending());
- ratelimit++;
- }
+ softirq_check_pending_idle();
return false;
}
@@ -1110,6 +1118,7 @@
* Emulate tick processing via per-CPU hrtimers:
*/
hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ ts->sched_timer.irqsafe = 1;
ts->sched_timer.function = tick_sched_timer;
/* Get the next period (per cpu) */
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index bfca770..d3150a7 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1754,7 +1754,9 @@
*/
void xtime_update(unsigned long ticks)
{
- write_seqlock(&jiffies_lock);
+ raw_spin_lock(&jiffies_lock);
+ write_seqcount_begin(&jiffies_seq);
do_timer(ticks);
- write_sequnlock(&jiffies_lock);
+ write_seqcount_end(&jiffies_seq);
+ raw_spin_unlock(&jiffies_lock);
}
diff --git a/kernel/timer.c b/kernel/timer.c
index 58879f9..431bbe0 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -78,9 +78,13 @@
struct tvec_base {
spinlock_t lock;
struct timer_list *running_timer;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ wait_queue_head_t wait_for_running_timer;
+#endif
unsigned long timer_jiffies;
unsigned long next_timer;
unsigned long active_timers;
+ unsigned long all_timers;
struct tvec_root tv1;
struct tvec tv2;
struct tvec tv3;
@@ -337,6 +341,20 @@
}
EXPORT_SYMBOL_GPL(set_timer_slack);
+/*
+ * If the list is empty, catch up ->timer_jiffies to the current time.
+ * The caller must hold the tvec_base lock. Returns true if the list
+ * was empty and therefore ->timer_jiffies was updated.
+ */
+static bool catchup_timer_jiffies(struct tvec_base *base)
+{
+ if (!base->all_timers) {
+ base->timer_jiffies = jiffies;
+ return true;
+ }
+ return false;
+}
+
static void
__internal_add_timer(struct tvec_base *base, struct timer_list *timer)
{
@@ -383,6 +401,7 @@
static void internal_add_timer(struct tvec_base *base, struct timer_list *timer)
{
+ (void)catchup_timer_jiffies(base);
__internal_add_timer(base, timer);
/*
* Update base->active_timers and base->next_timer
@@ -392,6 +411,7 @@
base->next_timer = timer->expires;
base->active_timers++;
}
+ base->all_timers++;
}
#ifdef CONFIG_TIMER_STATS
@@ -671,6 +691,8 @@
detach_timer(timer, true);
if (!tbase_get_deferrable(timer->base))
base->active_timers--;
+ base->all_timers--;
+ (void)catchup_timer_jiffies(base);
}
static int detach_if_pending(struct timer_list *timer, struct tvec_base *base,
@@ -685,6 +707,8 @@
if (timer->expires == base->next_timer)
base->next_timer = base->timer_jiffies;
}
+ base->all_timers--;
+ (void)catchup_timer_jiffies(base);
return 1;
}
@@ -720,6 +744,36 @@
}
}
+#ifndef CONFIG_PREEMPT_RT_FULL
+static inline struct tvec_base *switch_timer_base(struct timer_list *timer,
+ struct tvec_base *old,
+ struct tvec_base *new)
+{
+ /* See the comment in lock_timer_base() */
+ timer_set_base(timer, NULL);
+ spin_unlock(&old->lock);
+ spin_lock(&new->lock);
+ timer_set_base(timer, new);
+ return new;
+}
+#else
+static inline struct tvec_base *switch_timer_base(struct timer_list *timer,
+ struct tvec_base *old,
+ struct tvec_base *new)
+{
+ /*
+ * We cannot do the above because we might be preempted and
+ * then the preempter would see NULL and loop forever.
+ */
+ if (spin_trylock(&new->lock)) {
+ timer_set_base(timer, new);
+ spin_unlock(&old->lock);
+ return new;
+ }
+ return old;
+}
+#endif
+
static inline int
__mod_timer(struct timer_list *timer, unsigned long expires,
bool pending_only, int pinned)
@@ -739,12 +793,15 @@
debug_activate(timer, expires);
+ preempt_disable_rt();
cpu = smp_processor_id();
#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu))
cpu = get_nohz_timer_target();
#endif
+ preempt_enable_rt();
+
new_base = per_cpu(tvec_bases, cpu);
if (base != new_base) {
@@ -755,14 +812,8 @@
* handler yet has not finished. This also guarantees that
* the timer is serialized wrt itself.
*/
- if (likely(base->running_timer != timer)) {
- /* See the comment in lock_timer_base() */
- timer_set_base(timer, NULL);
- spin_unlock(&base->lock);
- base = new_base;
- spin_lock(&base->lock);
- timer_set_base(timer, base);
- }
+ if (likely(base->running_timer != timer))
+ base = switch_timer_base(timer, base, new_base);
}
timer->expires = expires;
@@ -958,6 +1009,29 @@
}
EXPORT_SYMBOL_GPL(add_timer_on);
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * Wait for a running timer
+ */
+static void wait_for_running_timer(struct timer_list *timer)
+{
+ struct tvec_base *base = timer->base;
+
+ if (base->running_timer == timer)
+ wait_event(base->wait_for_running_timer,
+ base->running_timer != timer);
+}
+
+# define wakeup_timer_waiters(b) wake_up_all(&(b)->wait_for_running_timer)
+#else
+static inline void wait_for_running_timer(struct timer_list *timer)
+{
+ cpu_relax();
+}
+
+# define wakeup_timer_waiters(b) do { } while (0)
+#endif
+
/**
* del_timer - deactive a timer.
* @timer: the timer to be deactivated
@@ -1015,7 +1089,7 @@
}
EXPORT_SYMBOL(try_to_del_timer_sync);
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
/**
* del_timer_sync - deactivate a timer and wait for the handler to finish.
* @timer: the timer to be deactivated
@@ -1075,7 +1149,7 @@
int ret = try_to_del_timer_sync(timer);
if (ret >= 0)
return ret;
- cpu_relax();
+ wait_for_running_timer(timer);
}
}
EXPORT_SYMBOL(del_timer_sync);
@@ -1159,6 +1233,10 @@
struct timer_list *timer;
spin_lock_irq(&base->lock);
+ if (catchup_timer_jiffies(base)) {
+ spin_unlock_irq(&base->lock);
+ return;
+ }
while (time_after_eq(jiffies, base->timer_jiffies)) {
struct list_head work_list;
struct list_head *head = &work_list;
@@ -1192,16 +1270,18 @@
if (irqsafe) {
spin_unlock(&base->lock);
call_timer_fn(timer, fn, data);
+ base->running_timer = NULL;
spin_lock(&base->lock);
} else {
spin_unlock_irq(&base->lock);
call_timer_fn(timer, fn, data);
+ base->running_timer = NULL;
spin_lock_irq(&base->lock);
}
}
}
- base->running_timer = NULL;
spin_unlock_irq(&base->lock);
+ wakeup_timer_waiters(base);
}
#ifdef CONFIG_NO_HZ_COMMON
@@ -1340,17 +1420,31 @@
if (cpu_is_offline(smp_processor_id()))
return expires;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /*
+ * On PREEMPT_RT we cannot sleep here. If the trylock does not
+ * succeed then we return the worst-case 'expires in 1 tick'
+ * value. We use the rt functions here directly to avoid a
+ * migrate_disable() call.
+ */
+ if (!spin_do_trylock(&base->lock))
+ return now + 1;
+#else
spin_lock(&base->lock);
+#endif
if (base->active_timers) {
if (time_before_eq(base->next_timer, base->timer_jiffies))
base->next_timer = __next_timer_interrupt(base);
expires = base->next_timer;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+ rt_spin_unlock_after_trylock_in_irq(&base->lock);
+#else
spin_unlock(&base->lock);
+#endif
if (time_before_eq(expires, now))
return now;
-
return cmp_next_hrtimer_event(now, expires);
}
#endif
@@ -1366,13 +1460,13 @@
/* Note: this timer irq context must be accounted for as well. */
account_process_tick(p, user_tick);
+ scheduler_tick();
run_local_timers();
rcu_check_callbacks(cpu, user_tick);
-#ifdef CONFIG_IRQ_WORK
+#if defined(CONFIG_IRQ_WORK)
if (in_irq())
irq_work_run();
#endif
- scheduler_tick();
run_posix_cpu_timers(p);
}
@@ -1385,6 +1479,8 @@
hrtimer_run_pending();
+ irq_work_tick_soft();
+
if (time_after_eq(jiffies, base->timer_jiffies))
__run_timers(base);
}
@@ -1560,6 +1656,9 @@
base = per_cpu(tvec_bases, cpu);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+ init_waitqueue_head(&base->wait_for_running_timer);
+#endif
for (j = 0; j < TVN_SIZE; j++) {
INIT_LIST_HEAD(base->tv5.vec + j);
@@ -1573,6 +1672,7 @@
base->timer_jiffies = jiffies;
base->next_timer = base->timer_jiffies;
base->active_timers = 0;
+ base->all_timers = 0;
return 0;
}
@@ -1598,7 +1698,7 @@
BUG_ON(cpu_online(cpu));
old_base = per_cpu(tvec_bases, cpu);
- new_base = get_cpu_var(tvec_bases);
+ new_base = get_local_var(tvec_bases);
/*
* The caller is globally serialized and nobody else
* takes two locks at once, deadlock is not possible.
@@ -1619,7 +1719,7 @@
spin_unlock(&old_base->lock);
spin_unlock_irq(&new_base->lock);
- put_cpu_var(tvec_bases);
+ put_local_var(tvec_bases);
}
#endif /* CONFIG_HOTPLUG_CPU */
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 015f85a..bbe95b9 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -192,6 +192,24 @@
enabled. This option and the preempt-off timing option can be
used together or separately.)
+config INTERRUPT_OFF_HIST
+ bool "Interrupts-off Latency Histogram"
+ depends on IRQSOFF_TRACER
+ help
+ This option generates continuously updated histograms (one per cpu)
+ of the duration of time periods with interrupts disabled. The
+ histograms are disabled by default. To enable them, write a non-zero
+ number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/preemptirqsoff
+
+ If PREEMPT_OFF_HIST is also selected, additional histograms (one
+ per cpu) are generated that accumulate the duration of time periods
+ when both interrupts and preemption are disabled. The histogram data
+ will be located in the debug file system at
+
+ /sys/kernel/debug/tracing/latency_hist/irqsoff
+
config PREEMPT_TRACER
bool "Preemption-off Latency Tracer"
default n
@@ -216,6 +234,24 @@
enabled. This option and the irqs-off timing option can be
used together or separately.)
+config PREEMPT_OFF_HIST
+ bool "Preemption-off Latency Histogram"
+ depends on PREEMPT_TRACER
+ help
+ This option generates continuously updated histograms (one per cpu)
+ of the duration of time periods with preemption disabled. The
+ histograms are disabled by default. To enable them, write a non-zero
+ number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/preemptirqsoff
+
+ If INTERRUPT_OFF_HIST is also selected, additional histograms (one
+ per cpu) are generated that accumulate the duration of time periods
+ when both interrupts and preemption are disabled. The histogram data
+ will be located in the debug file system at
+
+ /sys/kernel/debug/tracing/latency_hist/preemptoff
+
config SCHED_TRACER
bool "Scheduling Latency Tracer"
select GENERIC_TRACER
@@ -226,6 +262,74 @@
This tracer tracks the latency of the highest priority task
to be scheduled in, starting from the point it has woken up.
+config WAKEUP_LATENCY_HIST
+ bool "Scheduling Latency Histogram"
+ depends on SCHED_TRACER
+ help
+ This option generates continuously updated histograms (one per cpu)
+ of the scheduling latency of the highest priority task.
+ The histograms are disabled by default. To enable them, write a
+ non-zero number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/wakeup
+
+ Two different algorithms are used, one to determine the latency of
+ processes that exclusively use the highest priority of the system and
+ another one to determine the latency of processes that share the
+ highest system priority with other processes. The former is used to
+ improve hardware and system software, the latter to optimize the
+ priority design of a given system. The histogram data will be
+ located in the debug file system at
+
+ /sys/kernel/debug/tracing/latency_hist/wakeup
+
+ and
+
+ /sys/kernel/debug/tracing/latency_hist/wakeup/sharedprio
+
+ If both Scheduling Latency Histogram and Missed Timer Offsets
+ Histogram are selected, additional histogram data will be collected
+ that contain, in addition to the wakeup latency, the timer latency, in
+ case the wakeup was triggered by an expired timer. These histograms
+ are available in the
+
+ /sys/kernel/debug/tracing/latency_hist/timerandwakeup
+
+ directory. They reflect the apparent interrupt and scheduling latency
+ and are best suitable to determine the worst-case latency of a given
+ system. To enable these histograms, write a non-zero number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/timerandwakeup
+
+config MISSED_TIMER_OFFSETS_HIST
+ depends on HIGH_RES_TIMERS
+ select GENERIC_TRACER
+ bool "Missed Timer Offsets Histogram"
+ help
+ Generate a histogram of missed timer offsets in microseconds. The
+ histograms are disabled by default. To enable them, write a non-zero
+ number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/missed_timer_offsets
+
+ The histogram data will be located in the debug file system at
+
+ /sys/kernel/debug/tracing/latency_hist/missed_timer_offsets
+
+ If both Scheduling Latency Histogram and Missed Timer Offsets
+ Histogram are selected, additional histogram data will be collected
+ that contain, in addition to the wakeup latency, the timer latency, in
+ case the wakeup was triggered by an expired timer. These histograms
+ are available in the
+
+ /sys/kernel/debug/tracing/latency_hist/timerandwakeup
+
+ directory. They reflect the apparent interrupt and scheduling latency
+ and are best suitable to determine the worst-case latency of a given
+ system. To enable these histograms, write a non-zero number to
+
+ /sys/kernel/debug/tracing/latency_hist/enable/timerandwakeup
+
config ENABLE_DEFAULT_TRACERS
bool "Trace process context switches and events"
depends on !GENERIC_TRACER
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 67d201b..7bbe110 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -38,6 +38,10 @@
obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o
obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o
obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o
+obj-$(CONFIG_INTERRUPT_OFF_HIST) += latency_hist.o
+obj-$(CONFIG_PREEMPT_OFF_HIST) += latency_hist.o
+obj-$(CONFIG_WAKEUP_LATENCY_HIST) += latency_hist.o
+obj-$(CONFIG_MISSED_TIMER_OFFSETS_HIST) += latency_hist.o
obj-$(CONFIG_NOP_TRACER) += trace_nop.o
obj-$(CONFIG_STACK_TRACER) += trace_stack.o
obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
diff --git a/kernel/trace/latency_hist.c b/kernel/trace/latency_hist.c
new file mode 100644
index 0000000..b6c1d14
--- /dev/null
+++ b/kernel/trace/latency_hist.c
@@ -0,0 +1,1178 @@
+/*
+ * kernel/trace/latency_hist.c
+ *
+ * Add support for histograms of preemption-off latency and
+ * interrupt-off latency and wakeup latency, it depends on
+ * Real-Time Preemption Support.
+ *
+ * Copyright (C) 2005 MontaVista Software, Inc.
+ * Yi Yang <yyang@ch.mvista.com>
+ *
+ * Converted to work with the new latency tracer.
+ * Copyright (C) 2008 Red Hat, Inc.
+ * Steven Rostedt <srostedt@redhat.com>
+ *
+ */
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/percpu.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
+#include <linux/sched.h>
+#include <linux/sched/rt.h>
+#include <linux/slab.h>
+#include <linux/atomic.h>
+#include <asm/div64.h>
+
+#include "trace.h"
+#include <trace/events/sched.h>
+
+#define NSECS_PER_USECS 1000L
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/hist.h>
+
+enum {
+ IRQSOFF_LATENCY = 0,
+ PREEMPTOFF_LATENCY,
+ PREEMPTIRQSOFF_LATENCY,
+ WAKEUP_LATENCY,
+ WAKEUP_LATENCY_SHAREDPRIO,
+ MISSED_TIMER_OFFSETS,
+ TIMERANDWAKEUP_LATENCY,
+ MAX_LATENCY_TYPE,
+};
+
+#define MAX_ENTRY_NUM 10240
+
+struct hist_data {
+ atomic_t hist_mode; /* 0 log, 1 don't log */
+ long offset; /* set it to MAX_ENTRY_NUM/2 for a bipolar scale */
+ long min_lat;
+ long max_lat;
+ unsigned long long below_hist_bound_samples;
+ unsigned long long above_hist_bound_samples;
+ long long accumulate_lat;
+ unsigned long long total_samples;
+ unsigned long long hist_array[MAX_ENTRY_NUM];
+};
+
+struct enable_data {
+ int latency_type;
+ int enabled;
+};
+
+static char *latency_hist_dir_root = "latency_hist";
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+static DEFINE_PER_CPU(struct hist_data, irqsoff_hist);
+static char *irqsoff_hist_dir = "irqsoff";
+static DEFINE_PER_CPU(cycles_t, hist_irqsoff_start);
+static DEFINE_PER_CPU(int, hist_irqsoff_counting);
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+static DEFINE_PER_CPU(struct hist_data, preemptoff_hist);
+static char *preemptoff_hist_dir = "preemptoff";
+static DEFINE_PER_CPU(cycles_t, hist_preemptoff_start);
+static DEFINE_PER_CPU(int, hist_preemptoff_counting);
+#endif
+
+#if defined(CONFIG_PREEMPT_OFF_HIST) && defined(CONFIG_INTERRUPT_OFF_HIST)
+static DEFINE_PER_CPU(struct hist_data, preemptirqsoff_hist);
+static char *preemptirqsoff_hist_dir = "preemptirqsoff";
+static DEFINE_PER_CPU(cycles_t, hist_preemptirqsoff_start);
+static DEFINE_PER_CPU(int, hist_preemptirqsoff_counting);
+#endif
+
+#if defined(CONFIG_PREEMPT_OFF_HIST) || defined(CONFIG_INTERRUPT_OFF_HIST)
+static notrace void probe_preemptirqsoff_hist(void *v, int reason, int start);
+static struct enable_data preemptirqsoff_enabled_data = {
+ .latency_type = PREEMPTIRQSOFF_LATENCY,
+ .enabled = 0,
+};
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+struct maxlatproc_data {
+ char comm[FIELD_SIZEOF(struct task_struct, comm)];
+ char current_comm[FIELD_SIZEOF(struct task_struct, comm)];
+ int pid;
+ int current_pid;
+ int prio;
+ int current_prio;
+ long latency;
+ long timeroffset;
+ cycle_t timestamp;
+};
+#endif
+
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+static DEFINE_PER_CPU(struct hist_data, wakeup_latency_hist);
+static DEFINE_PER_CPU(struct hist_data, wakeup_latency_hist_sharedprio);
+static char *wakeup_latency_hist_dir = "wakeup";
+static char *wakeup_latency_hist_dir_sharedprio = "sharedprio";
+static notrace void probe_wakeup_latency_hist_start(void *v,
+ struct task_struct *p);
+static notrace void probe_wakeup_latency_hist_stop(void *v,
+ struct task_struct *prev, struct task_struct *next);
+static notrace void probe_sched_migrate_task(void *,
+ struct task_struct *task, int cpu);
+static struct enable_data wakeup_latency_enabled_data = {
+ .latency_type = WAKEUP_LATENCY,
+ .enabled = 0,
+};
+static DEFINE_PER_CPU(struct maxlatproc_data, wakeup_maxlatproc);
+static DEFINE_PER_CPU(struct maxlatproc_data, wakeup_maxlatproc_sharedprio);
+static DEFINE_PER_CPU(struct task_struct *, wakeup_task);
+static DEFINE_PER_CPU(int, wakeup_sharedprio);
+static unsigned long wakeup_pid;
+#endif
+
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+static DEFINE_PER_CPU(struct hist_data, missed_timer_offsets);
+static char *missed_timer_offsets_dir = "missed_timer_offsets";
+static notrace void probe_hrtimer_interrupt(void *v, int cpu,
+ long long offset, struct task_struct *curr, struct task_struct *task);
+static struct enable_data missed_timer_offsets_enabled_data = {
+ .latency_type = MISSED_TIMER_OFFSETS,
+ .enabled = 0,
+};
+static DEFINE_PER_CPU(struct maxlatproc_data, missed_timer_offsets_maxlatproc);
+static unsigned long missed_timer_offsets_pid;
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static DEFINE_PER_CPU(struct hist_data, timerandwakeup_latency_hist);
+static char *timerandwakeup_latency_hist_dir = "timerandwakeup";
+static struct enable_data timerandwakeup_enabled_data = {
+ .latency_type = TIMERANDWAKEUP_LATENCY,
+ .enabled = 0,
+};
+static DEFINE_PER_CPU(struct maxlatproc_data, timerandwakeup_maxlatproc);
+#endif
+
+void notrace latency_hist(int latency_type, int cpu, long latency,
+ long timeroffset, cycle_t stop,
+ struct task_struct *p)
+{
+ struct hist_data *my_hist;
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ struct maxlatproc_data *mp = NULL;
+#endif
+
+ if (!cpu_possible(cpu) || latency_type < 0 ||
+ latency_type >= MAX_LATENCY_TYPE)
+ return;
+
+ switch (latency_type) {
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ case IRQSOFF_LATENCY:
+ my_hist = &per_cpu(irqsoff_hist, cpu);
+ break;
+#endif
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ case PREEMPTOFF_LATENCY:
+ my_hist = &per_cpu(preemptoff_hist, cpu);
+ break;
+#endif
+#if defined(CONFIG_PREEMPT_OFF_HIST) && defined(CONFIG_INTERRUPT_OFF_HIST)
+ case PREEMPTIRQSOFF_LATENCY:
+ my_hist = &per_cpu(preemptirqsoff_hist, cpu);
+ break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ case WAKEUP_LATENCY:
+ my_hist = &per_cpu(wakeup_latency_hist, cpu);
+ mp = &per_cpu(wakeup_maxlatproc, cpu);
+ break;
+ case WAKEUP_LATENCY_SHAREDPRIO:
+ my_hist = &per_cpu(wakeup_latency_hist_sharedprio, cpu);
+ mp = &per_cpu(wakeup_maxlatproc_sharedprio, cpu);
+ break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ case MISSED_TIMER_OFFSETS:
+ my_hist = &per_cpu(missed_timer_offsets, cpu);
+ mp = &per_cpu(missed_timer_offsets_maxlatproc, cpu);
+ break;
+#endif
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ case TIMERANDWAKEUP_LATENCY:
+ my_hist = &per_cpu(timerandwakeup_latency_hist, cpu);
+ mp = &per_cpu(timerandwakeup_maxlatproc, cpu);
+ break;
+#endif
+
+ default:
+ return;
+ }
+
+ latency += my_hist->offset;
+
+ if (atomic_read(&my_hist->hist_mode) == 0)
+ return;
+
+ if (latency < 0 || latency >= MAX_ENTRY_NUM) {
+ if (latency < 0)
+ my_hist->below_hist_bound_samples++;
+ else
+ my_hist->above_hist_bound_samples++;
+ } else
+ my_hist->hist_array[latency]++;
+
+ if (unlikely(latency > my_hist->max_lat ||
+ my_hist->min_lat == LONG_MAX)) {
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ if (latency_type == WAKEUP_LATENCY ||
+ latency_type == WAKEUP_LATENCY_SHAREDPRIO ||
+ latency_type == MISSED_TIMER_OFFSETS ||
+ latency_type == TIMERANDWAKEUP_LATENCY) {
+ strncpy(mp->comm, p->comm, sizeof(mp->comm));
+ strncpy(mp->current_comm, current->comm,
+ sizeof(mp->current_comm));
+ mp->pid = task_pid_nr(p);
+ mp->current_pid = task_pid_nr(current);
+ mp->prio = p->prio;
+ mp->current_prio = current->prio;
+ mp->latency = latency;
+ mp->timeroffset = timeroffset;
+ mp->timestamp = stop;
+ }
+#endif
+ my_hist->max_lat = latency;
+ }
+ if (unlikely(latency < my_hist->min_lat))
+ my_hist->min_lat = latency;
+ my_hist->total_samples++;
+ my_hist->accumulate_lat += latency;
+}
+
+static void *l_start(struct seq_file *m, loff_t *pos)
+{
+ loff_t *index_ptr = NULL;
+ loff_t index = *pos;
+ struct hist_data *my_hist = m->private;
+
+ if (index == 0) {
+ char minstr[32], avgstr[32], maxstr[32];
+
+ atomic_dec(&my_hist->hist_mode);
+
+ if (likely(my_hist->total_samples)) {
+ long avg = (long) div64_s64(my_hist->accumulate_lat,
+ my_hist->total_samples);
+ snprintf(minstr, sizeof(minstr), "%ld",
+ my_hist->min_lat - my_hist->offset);
+ snprintf(avgstr, sizeof(avgstr), "%ld",
+ avg - my_hist->offset);
+ snprintf(maxstr, sizeof(maxstr), "%ld",
+ my_hist->max_lat - my_hist->offset);
+ } else {
+ strcpy(minstr, "<undef>");
+ strcpy(avgstr, minstr);
+ strcpy(maxstr, minstr);
+ }
+
+ seq_printf(m, "#Minimum latency: %s microseconds\n"
+ "#Average latency: %s microseconds\n"
+ "#Maximum latency: %s microseconds\n"
+ "#Total samples: %llu\n"
+ "#There are %llu samples lower than %ld"
+ " microseconds.\n"
+ "#There are %llu samples greater or equal"
+ " than %ld microseconds.\n"
+ "#usecs\t%16s\n",
+ minstr, avgstr, maxstr,
+ my_hist->total_samples,
+ my_hist->below_hist_bound_samples,
+ -my_hist->offset,
+ my_hist->above_hist_bound_samples,
+ MAX_ENTRY_NUM - my_hist->offset,
+ "samples");
+ }
+ if (index < MAX_ENTRY_NUM) {
+ index_ptr = kmalloc(sizeof(loff_t), GFP_KERNEL);
+ if (index_ptr)
+ *index_ptr = index;
+ }
+
+ return index_ptr;
+}
+
+static void *l_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ loff_t *index_ptr = p;
+ struct hist_data *my_hist = m->private;
+
+ if (++*pos >= MAX_ENTRY_NUM) {
+ atomic_inc(&my_hist->hist_mode);
+ return NULL;
+ }
+ *index_ptr = *pos;
+ return index_ptr;
+}
+
+static void l_stop(struct seq_file *m, void *p)
+{
+ kfree(p);
+}
+
+static int l_show(struct seq_file *m, void *p)
+{
+ int index = *(loff_t *) p;
+ struct hist_data *my_hist = m->private;
+
+ seq_printf(m, "%6ld\t%16llu\n", index - my_hist->offset,
+ my_hist->hist_array[index]);
+ return 0;
+}
+
+static const struct seq_operations latency_hist_seq_op = {
+ .start = l_start,
+ .next = l_next,
+ .stop = l_stop,
+ .show = l_show
+};
+
+static int latency_hist_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ ret = seq_open(file, &latency_hist_seq_op);
+ if (!ret) {
+ struct seq_file *seq = file->private_data;
+ seq->private = inode->i_private;
+ }
+ return ret;
+}
+
+static const struct file_operations latency_hist_fops = {
+ .open = latency_hist_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static void clear_maxlatprocdata(struct maxlatproc_data *mp)
+{
+ mp->comm[0] = mp->current_comm[0] = '\0';
+ mp->prio = mp->current_prio = mp->pid = mp->current_pid =
+ mp->latency = mp->timeroffset = -1;
+ mp->timestamp = 0;
+}
+#endif
+
+static void hist_reset(struct hist_data *hist)
+{
+ atomic_dec(&hist->hist_mode);
+
+ memset(hist->hist_array, 0, sizeof(hist->hist_array));
+ hist->below_hist_bound_samples = 0ULL;
+ hist->above_hist_bound_samples = 0ULL;
+ hist->min_lat = LONG_MAX;
+ hist->max_lat = LONG_MIN;
+ hist->total_samples = 0ULL;
+ hist->accumulate_lat = 0LL;
+
+ atomic_inc(&hist->hist_mode);
+}
+
+static ssize_t
+latency_hist_reset(struct file *file, const char __user *a,
+ size_t size, loff_t *off)
+{
+ int cpu;
+ struct hist_data *hist = NULL;
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ struct maxlatproc_data *mp = NULL;
+#endif
+ off_t latency_type = (off_t) file->private_data;
+
+ for_each_online_cpu(cpu) {
+
+ switch (latency_type) {
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ case PREEMPTOFF_LATENCY:
+ hist = &per_cpu(preemptoff_hist, cpu);
+ break;
+#endif
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ case IRQSOFF_LATENCY:
+ hist = &per_cpu(irqsoff_hist, cpu);
+ break;
+#endif
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+ case PREEMPTIRQSOFF_LATENCY:
+ hist = &per_cpu(preemptirqsoff_hist, cpu);
+ break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ case WAKEUP_LATENCY:
+ hist = &per_cpu(wakeup_latency_hist, cpu);
+ mp = &per_cpu(wakeup_maxlatproc, cpu);
+ break;
+ case WAKEUP_LATENCY_SHAREDPRIO:
+ hist = &per_cpu(wakeup_latency_hist_sharedprio, cpu);
+ mp = &per_cpu(wakeup_maxlatproc_sharedprio, cpu);
+ break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ case MISSED_TIMER_OFFSETS:
+ hist = &per_cpu(missed_timer_offsets, cpu);
+ mp = &per_cpu(missed_timer_offsets_maxlatproc, cpu);
+ break;
+#endif
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ case TIMERANDWAKEUP_LATENCY:
+ hist = &per_cpu(timerandwakeup_latency_hist, cpu);
+ mp = &per_cpu(timerandwakeup_maxlatproc, cpu);
+ break;
+#endif
+ }
+
+ hist_reset(hist);
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ if (latency_type == WAKEUP_LATENCY ||
+ latency_type == WAKEUP_LATENCY_SHAREDPRIO ||
+ latency_type == MISSED_TIMER_OFFSETS ||
+ latency_type == TIMERANDWAKEUP_LATENCY)
+ clear_maxlatprocdata(mp);
+#endif
+ }
+
+ return size;
+}
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static ssize_t
+show_pid(struct file *file, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ int r;
+ unsigned long *this_pid = file->private_data;
+
+ r = snprintf(buf, sizeof(buf), "%lu\n", *this_pid);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t do_pid(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ unsigned long pid;
+ unsigned long *this_pid = file->private_data;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = '\0';
+
+ if (kstrtoul(buf, 10, &pid))
+ return -EINVAL;
+
+ *this_pid = pid;
+
+ return cnt;
+}
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static ssize_t
+show_maxlatproc(struct file *file, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ int r;
+ struct maxlatproc_data *mp = file->private_data;
+ int strmaxlen = (TASK_COMM_LEN * 2) + (8 * 8);
+ unsigned long long t;
+ unsigned long usecs, secs;
+ char *buf;
+
+ if (mp->pid == -1 || mp->current_pid == -1) {
+ buf = "(none)\n";
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf,
+ strlen(buf));
+ }
+
+ buf = kmalloc(strmaxlen, GFP_KERNEL);
+ if (buf == NULL)
+ return -ENOMEM;
+
+ t = ns2usecs(mp->timestamp);
+ usecs = do_div(t, USEC_PER_SEC);
+ secs = (unsigned long) t;
+ r = snprintf(buf, strmaxlen,
+ "%d %d %ld (%ld) %s <- %d %d %s %lu.%06lu\n", mp->pid,
+ MAX_RT_PRIO-1 - mp->prio, mp->latency, mp->timeroffset, mp->comm,
+ mp->current_pid, MAX_RT_PRIO-1 - mp->current_prio, mp->current_comm,
+ secs, usecs);
+ r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+ kfree(buf);
+ return r;
+}
+#endif
+
+static ssize_t
+show_enable(struct file *file, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ struct enable_data *ed = file->private_data;
+ int r;
+
+ r = snprintf(buf, sizeof(buf), "%d\n", ed->enabled);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+do_enable(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ long enable;
+ struct enable_data *ed = file->private_data;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ if (kstrtoul(buf, 10, &enable))
+ return -EINVAL;
+
+ if ((enable && ed->enabled) || (!enable && !ed->enabled))
+ return cnt;
+
+ if (enable) {
+ int ret;
+
+ switch (ed->latency_type) {
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+ case PREEMPTIRQSOFF_LATENCY:
+ ret = register_trace_preemptirqsoff_hist(
+ probe_preemptirqsoff_hist, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_preemptirqsoff_hist "
+ "to trace_preemptirqsoff_hist\n");
+ return ret;
+ }
+ break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ case WAKEUP_LATENCY:
+ ret = register_trace_sched_wakeup(
+ probe_wakeup_latency_hist_start, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_wakeup_latency_hist_start "
+ "to trace_sched_wakeup\n");
+ return ret;
+ }
+ ret = register_trace_sched_wakeup_new(
+ probe_wakeup_latency_hist_start, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_wakeup_latency_hist_start "
+ "to trace_sched_wakeup_new\n");
+ unregister_trace_sched_wakeup(
+ probe_wakeup_latency_hist_start, NULL);
+ return ret;
+ }
+ ret = register_trace_sched_switch(
+ probe_wakeup_latency_hist_stop, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_wakeup_latency_hist_stop "
+ "to trace_sched_switch\n");
+ unregister_trace_sched_wakeup(
+ probe_wakeup_latency_hist_start, NULL);
+ unregister_trace_sched_wakeup_new(
+ probe_wakeup_latency_hist_start, NULL);
+ return ret;
+ }
+ ret = register_trace_sched_migrate_task(
+ probe_sched_migrate_task, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_sched_migrate_task "
+ "to trace_sched_migrate_task\n");
+ unregister_trace_sched_wakeup(
+ probe_wakeup_latency_hist_start, NULL);
+ unregister_trace_sched_wakeup_new(
+ probe_wakeup_latency_hist_start, NULL);
+ unregister_trace_sched_switch(
+ probe_wakeup_latency_hist_stop, NULL);
+ return ret;
+ }
+ break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ case MISSED_TIMER_OFFSETS:
+ ret = register_trace_hrtimer_interrupt(
+ probe_hrtimer_interrupt, NULL);
+ if (ret) {
+ pr_info("wakeup trace: Couldn't assign "
+ "probe_hrtimer_interrupt "
+ "to trace_hrtimer_interrupt\n");
+ return ret;
+ }
+ break;
+#endif
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ case TIMERANDWAKEUP_LATENCY:
+ if (!wakeup_latency_enabled_data.enabled ||
+ !missed_timer_offsets_enabled_data.enabled)
+ return -EINVAL;
+ break;
+#endif
+ default:
+ break;
+ }
+ } else {
+ switch (ed->latency_type) {
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+ case PREEMPTIRQSOFF_LATENCY:
+ {
+ int cpu;
+
+ unregister_trace_preemptirqsoff_hist(
+ probe_preemptirqsoff_hist, NULL);
+ for_each_online_cpu(cpu) {
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ per_cpu(hist_irqsoff_counting,
+ cpu) = 0;
+#endif
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ per_cpu(hist_preemptoff_counting,
+ cpu) = 0;
+#endif
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+ per_cpu(hist_preemptirqsoff_counting,
+ cpu) = 0;
+#endif
+ }
+ }
+ break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ case WAKEUP_LATENCY:
+ {
+ int cpu;
+
+ unregister_trace_sched_wakeup(
+ probe_wakeup_latency_hist_start, NULL);
+ unregister_trace_sched_wakeup_new(
+ probe_wakeup_latency_hist_start, NULL);
+ unregister_trace_sched_switch(
+ probe_wakeup_latency_hist_stop, NULL);
+ unregister_trace_sched_migrate_task(
+ probe_sched_migrate_task, NULL);
+
+ for_each_online_cpu(cpu) {
+ per_cpu(wakeup_task, cpu) = NULL;
+ per_cpu(wakeup_sharedprio, cpu) = 0;
+ }
+ }
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ timerandwakeup_enabled_data.enabled = 0;
+#endif
+ break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ case MISSED_TIMER_OFFSETS:
+ unregister_trace_hrtimer_interrupt(
+ probe_hrtimer_interrupt, NULL);
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ timerandwakeup_enabled_data.enabled = 0;
+#endif
+ break;
+#endif
+ default:
+ break;
+ }
+ }
+ ed->enabled = enable;
+ return cnt;
+}
+
+static const struct file_operations latency_hist_reset_fops = {
+ .open = tracing_open_generic,
+ .write = latency_hist_reset,
+};
+
+static const struct file_operations enable_fops = {
+ .open = tracing_open_generic,
+ .read = show_enable,
+ .write = do_enable,
+};
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static const struct file_operations pid_fops = {
+ .open = tracing_open_generic,
+ .read = show_pid,
+ .write = do_pid,
+};
+
+static const struct file_operations maxlatproc_fops = {
+ .open = tracing_open_generic,
+ .read = show_maxlatproc,
+};
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+static notrace void probe_preemptirqsoff_hist(void *v, int reason,
+ int starthist)
+{
+ int cpu = raw_smp_processor_id();
+ int time_set = 0;
+
+ if (starthist) {
+ cycle_t uninitialized_var(start);
+
+ if (!preempt_count() && !irqs_disabled())
+ return;
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ if ((reason == IRQS_OFF || reason == TRACE_START) &&
+ !per_cpu(hist_irqsoff_counting, cpu)) {
+ per_cpu(hist_irqsoff_counting, cpu) = 1;
+ start = ftrace_now(cpu);
+ time_set++;
+ per_cpu(hist_irqsoff_start, cpu) = start;
+ }
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ if ((reason == PREEMPT_OFF || reason == TRACE_START) &&
+ !per_cpu(hist_preemptoff_counting, cpu)) {
+ per_cpu(hist_preemptoff_counting, cpu) = 1;
+ if (!(time_set++))
+ start = ftrace_now(cpu);
+ per_cpu(hist_preemptoff_start, cpu) = start;
+ }
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+ if (per_cpu(hist_irqsoff_counting, cpu) &&
+ per_cpu(hist_preemptoff_counting, cpu) &&
+ !per_cpu(hist_preemptirqsoff_counting, cpu)) {
+ per_cpu(hist_preemptirqsoff_counting, cpu) = 1;
+ if (!time_set)
+ start = ftrace_now(cpu);
+ per_cpu(hist_preemptirqsoff_start, cpu) = start;
+ }
+#endif
+ } else {
+ cycle_t uninitialized_var(stop);
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ if ((reason == IRQS_ON || reason == TRACE_STOP) &&
+ per_cpu(hist_irqsoff_counting, cpu)) {
+ cycle_t start = per_cpu(hist_irqsoff_start, cpu);
+
+ stop = ftrace_now(cpu);
+ time_set++;
+ if (start) {
+ long latency = ((long) (stop - start)) /
+ NSECS_PER_USECS;
+
+ latency_hist(IRQSOFF_LATENCY, cpu, latency, 0,
+ stop, NULL);
+ }
+ per_cpu(hist_irqsoff_counting, cpu) = 0;
+ }
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ if ((reason == PREEMPT_ON || reason == TRACE_STOP) &&
+ per_cpu(hist_preemptoff_counting, cpu)) {
+ cycle_t start = per_cpu(hist_preemptoff_start, cpu);
+
+ if (!(time_set++))
+ stop = ftrace_now(cpu);
+ if (start) {
+ long latency = ((long) (stop - start)) /
+ NSECS_PER_USECS;
+
+ latency_hist(PREEMPTOFF_LATENCY, cpu, latency,
+ 0, stop, NULL);
+ }
+ per_cpu(hist_preemptoff_counting, cpu) = 0;
+ }
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+ if ((!per_cpu(hist_irqsoff_counting, cpu) ||
+ !per_cpu(hist_preemptoff_counting, cpu)) &&
+ per_cpu(hist_preemptirqsoff_counting, cpu)) {
+ cycle_t start = per_cpu(hist_preemptirqsoff_start, cpu);
+
+ if (!time_set)
+ stop = ftrace_now(cpu);
+ if (start) {
+ long latency = ((long) (stop - start)) /
+ NSECS_PER_USECS;
+
+ latency_hist(PREEMPTIRQSOFF_LATENCY, cpu,
+ latency, 0, stop, NULL);
+ }
+ per_cpu(hist_preemptirqsoff_counting, cpu) = 0;
+ }
+#endif
+ }
+}
+#endif
+
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+static DEFINE_RAW_SPINLOCK(wakeup_lock);
+static notrace void probe_sched_migrate_task(void *v, struct task_struct *task,
+ int cpu)
+{
+ int old_cpu = task_cpu(task);
+
+ if (cpu != old_cpu) {
+ unsigned long flags;
+ struct task_struct *cpu_wakeup_task;
+
+ raw_spin_lock_irqsave(&wakeup_lock, flags);
+
+ cpu_wakeup_task = per_cpu(wakeup_task, old_cpu);
+ if (task == cpu_wakeup_task) {
+ put_task_struct(cpu_wakeup_task);
+ per_cpu(wakeup_task, old_cpu) = NULL;
+ cpu_wakeup_task = per_cpu(wakeup_task, cpu) = task;
+ get_task_struct(cpu_wakeup_task);
+ }
+
+ raw_spin_unlock_irqrestore(&wakeup_lock, flags);
+ }
+}
+
+static notrace void probe_wakeup_latency_hist_start(void *v,
+ struct task_struct *p)
+{
+ unsigned long flags;
+ struct task_struct *curr = current;
+ int cpu = task_cpu(p);
+ struct task_struct *cpu_wakeup_task;
+
+ raw_spin_lock_irqsave(&wakeup_lock, flags);
+
+ cpu_wakeup_task = per_cpu(wakeup_task, cpu);
+
+ if (wakeup_pid) {
+ if ((cpu_wakeup_task && p->prio == cpu_wakeup_task->prio) ||
+ p->prio == curr->prio)
+ per_cpu(wakeup_sharedprio, cpu) = 1;
+ if (likely(wakeup_pid != task_pid_nr(p)))
+ goto out;
+ } else {
+ if (likely(!rt_task(p)) ||
+ (cpu_wakeup_task && p->prio > cpu_wakeup_task->prio) ||
+ p->prio > curr->prio)
+ goto out;
+ if ((cpu_wakeup_task && p->prio == cpu_wakeup_task->prio) ||
+ p->prio == curr->prio)
+ per_cpu(wakeup_sharedprio, cpu) = 1;
+ }
+
+ if (cpu_wakeup_task)
+ put_task_struct(cpu_wakeup_task);
+ cpu_wakeup_task = per_cpu(wakeup_task, cpu) = p;
+ get_task_struct(cpu_wakeup_task);
+ cpu_wakeup_task->preempt_timestamp_hist =
+ ftrace_now(raw_smp_processor_id());
+out:
+ raw_spin_unlock_irqrestore(&wakeup_lock, flags);
+}
+
+static notrace void probe_wakeup_latency_hist_stop(void *v,
+ struct task_struct *prev, struct task_struct *next)
+{
+ unsigned long flags;
+ int cpu = task_cpu(next);
+ long latency;
+ cycle_t stop;
+ struct task_struct *cpu_wakeup_task;
+
+ raw_spin_lock_irqsave(&wakeup_lock, flags);
+
+ cpu_wakeup_task = per_cpu(wakeup_task, cpu);
+
+ if (cpu_wakeup_task == NULL)
+ goto out;
+
+ /* Already running? */
+ if (unlikely(current == cpu_wakeup_task))
+ goto out_reset;
+
+ if (next != cpu_wakeup_task) {
+ if (next->prio < cpu_wakeup_task->prio)
+ goto out_reset;
+
+ if (next->prio == cpu_wakeup_task->prio)
+ per_cpu(wakeup_sharedprio, cpu) = 1;
+
+ goto out;
+ }
+
+ if (current->prio == cpu_wakeup_task->prio)
+ per_cpu(wakeup_sharedprio, cpu) = 1;
+
+ /*
+ * The task we are waiting for is about to be switched to.
+ * Calculate latency and store it in histogram.
+ */
+ stop = ftrace_now(raw_smp_processor_id());
+
+ latency = ((long) (stop - next->preempt_timestamp_hist)) /
+ NSECS_PER_USECS;
+
+ if (per_cpu(wakeup_sharedprio, cpu)) {
+ latency_hist(WAKEUP_LATENCY_SHAREDPRIO, cpu, latency, 0, stop,
+ next);
+ per_cpu(wakeup_sharedprio, cpu) = 0;
+ } else {
+ latency_hist(WAKEUP_LATENCY, cpu, latency, 0, stop, next);
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ if (timerandwakeup_enabled_data.enabled) {
+ latency_hist(TIMERANDWAKEUP_LATENCY, cpu,
+ next->timer_offset + latency, next->timer_offset,
+ stop, next);
+ }
+#endif
+ }
+
+out_reset:
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ next->timer_offset = 0;
+#endif
+ put_task_struct(cpu_wakeup_task);
+ per_cpu(wakeup_task, cpu) = NULL;
+out:
+ raw_spin_unlock_irqrestore(&wakeup_lock, flags);
+}
+#endif
+
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+static notrace void probe_hrtimer_interrupt(void *v, int cpu,
+ long long latency_ns, struct task_struct *curr,
+ struct task_struct *task)
+{
+ if (latency_ns <= 0 && task != NULL && rt_task(task) &&
+ (task->prio < curr->prio ||
+ (task->prio == curr->prio &&
+ !cpumask_test_cpu(cpu, &task->cpus_allowed)))) {
+ long latency;
+ cycle_t now;
+
+ if (missed_timer_offsets_pid) {
+ if (likely(missed_timer_offsets_pid !=
+ task_pid_nr(task)))
+ return;
+ }
+
+ now = ftrace_now(cpu);
+ latency = (long) div_s64(-latency_ns, NSECS_PER_USECS);
+ latency_hist(MISSED_TIMER_OFFSETS, cpu, latency, latency, now,
+ task);
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ task->timer_offset = latency;
+#endif
+ }
+}
+#endif
+
+static __init int latency_hist_init(void)
+{
+ struct dentry *latency_hist_root = NULL;
+ struct dentry *dentry;
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ struct dentry *dentry_sharedprio;
+#endif
+ struct dentry *entry;
+ struct dentry *enable_root;
+ int i = 0;
+ struct hist_data *my_hist;
+ char name[64];
+ char *cpufmt = "CPU%d";
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ char *cpufmt_maxlatproc = "max_latency-CPU%d";
+ struct maxlatproc_data *mp = NULL;
+#endif
+
+ dentry = tracing_init_dentry();
+ latency_hist_root = debugfs_create_dir(latency_hist_dir_root, dentry);
+ enable_root = debugfs_create_dir("enable", latency_hist_root);
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+ dentry = debugfs_create_dir(irqsoff_hist_dir, latency_hist_root);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(irqsoff_hist, i), &latency_hist_fops);
+ my_hist = &per_cpu(irqsoff_hist, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+ }
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)IRQSOFF_LATENCY, &latency_hist_reset_fops);
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+ dentry = debugfs_create_dir(preemptoff_hist_dir,
+ latency_hist_root);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(preemptoff_hist, i), &latency_hist_fops);
+ my_hist = &per_cpu(preemptoff_hist, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+ }
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)PREEMPTOFF_LATENCY, &latency_hist_reset_fops);
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+ dentry = debugfs_create_dir(preemptirqsoff_hist_dir,
+ latency_hist_root);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(preemptirqsoff_hist, i), &latency_hist_fops);
+ my_hist = &per_cpu(preemptirqsoff_hist, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+ }
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)PREEMPTIRQSOFF_LATENCY, &latency_hist_reset_fops);
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+ entry = debugfs_create_file("preemptirqsoff", 0644,
+ enable_root, (void *)&preemptirqsoff_enabled_data,
+ &enable_fops);
+#endif
+
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+ dentry = debugfs_create_dir(wakeup_latency_hist_dir,
+ latency_hist_root);
+ dentry_sharedprio = debugfs_create_dir(
+ wakeup_latency_hist_dir_sharedprio, dentry);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(wakeup_latency_hist, i),
+ &latency_hist_fops);
+ my_hist = &per_cpu(wakeup_latency_hist, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+
+ entry = debugfs_create_file(name, 0444, dentry_sharedprio,
+ &per_cpu(wakeup_latency_hist_sharedprio, i),
+ &latency_hist_fops);
+ my_hist = &per_cpu(wakeup_latency_hist_sharedprio, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+
+ sprintf(name, cpufmt_maxlatproc, i);
+
+ mp = &per_cpu(wakeup_maxlatproc, i);
+ entry = debugfs_create_file(name, 0444, dentry, mp,
+ &maxlatproc_fops);
+ clear_maxlatprocdata(mp);
+
+ mp = &per_cpu(wakeup_maxlatproc_sharedprio, i);
+ entry = debugfs_create_file(name, 0444, dentry_sharedprio, mp,
+ &maxlatproc_fops);
+ clear_maxlatprocdata(mp);
+ }
+ entry = debugfs_create_file("pid", 0644, dentry,
+ (void *)&wakeup_pid, &pid_fops);
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)WAKEUP_LATENCY, &latency_hist_reset_fops);
+ entry = debugfs_create_file("reset", 0644, dentry_sharedprio,
+ (void *)WAKEUP_LATENCY_SHAREDPRIO, &latency_hist_reset_fops);
+ entry = debugfs_create_file("wakeup", 0644,
+ enable_root, (void *)&wakeup_latency_enabled_data,
+ &enable_fops);
+#endif
+
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+ dentry = debugfs_create_dir(missed_timer_offsets_dir,
+ latency_hist_root);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(missed_timer_offsets, i), &latency_hist_fops);
+ my_hist = &per_cpu(missed_timer_offsets, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+
+ sprintf(name, cpufmt_maxlatproc, i);
+ mp = &per_cpu(missed_timer_offsets_maxlatproc, i);
+ entry = debugfs_create_file(name, 0444, dentry, mp,
+ &maxlatproc_fops);
+ clear_maxlatprocdata(mp);
+ }
+ entry = debugfs_create_file("pid", 0644, dentry,
+ (void *)&missed_timer_offsets_pid, &pid_fops);
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)MISSED_TIMER_OFFSETS, &latency_hist_reset_fops);
+ entry = debugfs_create_file("missed_timer_offsets", 0644,
+ enable_root, (void *)&missed_timer_offsets_enabled_data,
+ &enable_fops);
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+ defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+ dentry = debugfs_create_dir(timerandwakeup_latency_hist_dir,
+ latency_hist_root);
+ for_each_possible_cpu(i) {
+ sprintf(name, cpufmt, i);
+ entry = debugfs_create_file(name, 0444, dentry,
+ &per_cpu(timerandwakeup_latency_hist, i),
+ &latency_hist_fops);
+ my_hist = &per_cpu(timerandwakeup_latency_hist, i);
+ atomic_set(&my_hist->hist_mode, 1);
+ my_hist->min_lat = LONG_MAX;
+
+ sprintf(name, cpufmt_maxlatproc, i);
+ mp = &per_cpu(timerandwakeup_maxlatproc, i);
+ entry = debugfs_create_file(name, 0444, dentry, mp,
+ &maxlatproc_fops);
+ clear_maxlatprocdata(mp);
+ }
+ entry = debugfs_create_file("reset", 0644, dentry,
+ (void *)TIMERANDWAKEUP_LATENCY, &latency_hist_reset_fops);
+ entry = debugfs_create_file("timerandwakeup", 0644,
+ enable_root, (void *)&timerandwakeup_enabled_data,
+ &enable_fops);
+#endif
+ return 0;
+}
+
+device_initcall(latency_hist_init);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index dbd488dae..51939563 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1522,6 +1522,7 @@
struct task_struct *tsk = current;
entry->preempt_count = pc & 0xff;
+ entry->preempt_lazy_count = preempt_lazy_count();
entry->pid = (tsk) ? tsk->pid : 0;
entry->flags =
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
@@ -1531,7 +1532,10 @@
#endif
((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
- (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
+ (need_resched_now() ? TRACE_FLAG_NEED_RESCHED : 0) |
+ (need_resched_lazy() ? TRACE_FLAG_NEED_RESCHED_LAZY : 0);
+
+ entry->migrate_disable = (tsk) ? __migrate_disabled(tsk) & 0xFF : 0;
}
EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
@@ -2421,14 +2425,17 @@
static void print_lat_help_header(struct seq_file *m)
{
- seq_puts(m, "# _------=> CPU# \n");
- seq_puts(m, "# / _-----=> irqs-off \n");
- seq_puts(m, "# | / _----=> need-resched \n");
- seq_puts(m, "# || / _---=> hardirq/softirq \n");
- seq_puts(m, "# ||| / _--=> preempt-depth \n");
- seq_puts(m, "# |||| / delay \n");
- seq_puts(m, "# cmd pid ||||| time | caller \n");
- seq_puts(m, "# \\ / ||||| \\ | / \n");
+ seq_puts(m, "# _--------=> CPU# \n"
+ "# / _-------=> irqs-off \n"
+ "# | / _------=> need-resched \n"
+ "# || / _-----=> need-resched_lazy \n"
+ "# ||| / _----=> hardirq/softirq \n"
+ "# |||| / _---=> preempt-depth \n"
+ "# ||||| / _--=> preempt-lazy-depth\n"
+ "# |||||| / _-=> migrate-disable \n"
+ "# ||||||| / delay \n"
+ "# cmd pid |||||||| time | caller \n"
+ "# \\ / |||||||| \\ | / \n");
}
static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
@@ -2452,13 +2459,16 @@
static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m)
{
print_event_info(buf, m);
- seq_puts(m, "# _-----=> irqs-off\n");
- seq_puts(m, "# / _----=> need-resched\n");
- seq_puts(m, "# | / _---=> hardirq/softirq\n");
- seq_puts(m, "# || / _--=> preempt-depth\n");
- seq_puts(m, "# ||| / delay\n");
- seq_puts(m, "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n");
- seq_puts(m, "# | | | |||| | |\n");
+ seq_puts(m, "# _-------=> irqs-off \n");
+ seq_puts(m, "# / _------=> need-resched \n");
+ seq_puts(m, "# |/ _-----=> need-resched_lazy \n");
+ seq_puts(m, "# ||/ _----=> hardirq/softirq \n");
+ seq_puts(m, "# |||/ _---=> preempt-depth \n");
+ seq_puts(m, "# ||||/ _--=> preempt-lazy-depth\n");
+ seq_puts(m, "# ||||| / _-=> migrate-disable \n");
+ seq_puts(m, "# |||||| / delay\n");
+ seq_puts(m, "# TASK-PID CPU# |||||| TIMESTAMP FUNCTION\n");
+ seq_puts(m, "# | | | |||||| | |\n");
}
void
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index be4f5037..29d7ea2 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -117,6 +117,7 @@
* NEED_RESCHED - reschedule is requested
* HARDIRQ - inside an interrupt handler
* SOFTIRQ - inside a softirq handler
+ * NEED_RESCHED_LAZY - lazy reschedule is requested
*/
enum trace_flag_type {
TRACE_FLAG_IRQS_OFF = 0x01,
@@ -124,6 +125,7 @@
TRACE_FLAG_NEED_RESCHED = 0x04,
TRACE_FLAG_HARDIRQ = 0x08,
TRACE_FLAG_SOFTIRQ = 0x10,
+ TRACE_FLAG_NEED_RESCHED_LAZY = 0x20,
};
#define TRACE_BUF_SIZE 1024
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 9514ee1..a37685c 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -160,6 +160,8 @@
__common_field(unsigned char, flags);
__common_field(unsigned char, preempt_count);
__common_field(int, pid);
+ __common_field(unsigned short, migrate_disable);
+ __common_field(unsigned short, padding);
return ret;
}
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 56e083e..44686b5 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -17,6 +17,7 @@
#include <linux/fs.h>
#include "trace.h"
+#include <trace/events/hist.h>
static struct trace_array *irqsoff_trace __read_mostly;
static int tracer_enabled __read_mostly;
@@ -443,11 +444,13 @@
{
if (preempt_trace() || irq_trace())
start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
+ trace_preemptirqsoff_hist_rcuidle(TRACE_START, 1);
}
EXPORT_SYMBOL_GPL(start_critical_timings);
void stop_critical_timings(void)
{
+ trace_preemptirqsoff_hist_rcuidle(TRACE_STOP, 0);
if (preempt_trace() || irq_trace())
stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
}
@@ -457,6 +460,7 @@
#ifdef CONFIG_PROVE_LOCKING
void time_hardirqs_on(unsigned long a0, unsigned long a1)
{
+ trace_preemptirqsoff_hist(IRQS_ON, 0);
if (!preempt_trace() && irq_trace())
stop_critical_timing(a0, a1);
}
@@ -465,6 +469,7 @@
{
if (!preempt_trace() && irq_trace())
start_critical_timing(a0, a1);
+ trace_preemptirqsoff_hist(IRQS_OFF, 1);
}
#else /* !CONFIG_PROVE_LOCKING */
@@ -490,6 +495,7 @@
*/
void trace_hardirqs_on(void)
{
+ trace_preemptirqsoff_hist_rcuidle(IRQS_ON, 0);
if (!preempt_trace() && irq_trace())
stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
}
@@ -499,11 +505,13 @@
{
if (!preempt_trace() && irq_trace())
start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
+ trace_preemptirqsoff_hist_rcuidle(IRQS_OFF, 1);
}
EXPORT_SYMBOL(trace_hardirqs_off);
void trace_hardirqs_on_caller(unsigned long caller_addr)
{
+ trace_preemptirqsoff_hist(IRQS_ON, 0);
if (!preempt_trace() && irq_trace())
stop_critical_timing(CALLER_ADDR0, caller_addr);
}
@@ -513,6 +521,7 @@
{
if (!preempt_trace() && irq_trace())
start_critical_timing(CALLER_ADDR0, caller_addr);
+ trace_preemptirqsoff_hist(IRQS_OFF, 1);
}
EXPORT_SYMBOL(trace_hardirqs_off_caller);
@@ -522,12 +531,14 @@
#ifdef CONFIG_PREEMPT_TRACER
void trace_preempt_on(unsigned long a0, unsigned long a1)
{
+ trace_preemptirqsoff_hist(PREEMPT_ON, 0);
if (preempt_trace() && !irq_trace())
stop_critical_timing(a0, a1);
}
void trace_preempt_off(unsigned long a0, unsigned long a1)
{
+ trace_preemptirqsoff_hist(PREEMPT_ON, 1);
if (preempt_trace() && !irq_trace())
start_critical_timing(a0, a1);
}
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 34e7cba..46b6467 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -606,6 +606,7 @@
{
char hardsoft_irq;
char need_resched;
+ char need_resched_lazy;
char irqs_off;
int hardirq;
int softirq;
@@ -620,14 +621,17 @@
'.';
need_resched =
(entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.';
+ need_resched_lazy =
+ (entry->flags & TRACE_FLAG_NEED_RESCHED_LAZY) ? 'L' : '.';
hardsoft_irq =
(hardirq && softirq) ? 'H' :
hardirq ? 'h' :
softirq ? 's' :
'.';
- if (!trace_seq_printf(s, "%c%c%c",
- irqs_off, need_resched, hardsoft_irq))
+ if (!trace_seq_printf(s, "%c%c%c%c",
+ irqs_off, need_resched, need_resched_lazy,
+ hardsoft_irq))
return 0;
if (entry->preempt_count)
@@ -635,6 +639,16 @@
else
ret = trace_seq_putc(s, '.');
+ if (entry->preempt_lazy_count)
+ ret = trace_seq_printf(s, "%x", entry->preempt_lazy_count);
+ else
+ ret = trace_seq_putc(s, '.');
+
+ if (entry->migrate_disable)
+ ret = trace_seq_printf(s, "%x", entry->migrate_disable);
+ else
+ ret = trace_seq_putc(s, '.');
+
return ret;
}
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 4e98e3b..82fe794 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -106,7 +106,7 @@
}
static void
-probe_sched_wakeup(void *ignore, struct task_struct *wakee, int success)
+probe_sched_wakeup(void *ignore, struct task_struct *wakee)
{
struct trace_array_cpu *data;
unsigned long flags;
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index fee77e1..8e967ca 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -458,7 +458,7 @@
}
static void
-probe_wakeup(void *ignore, struct task_struct *p, int success)
+probe_wakeup(void *ignore, struct task_struct *p)
{
struct trace_array_cpu *data;
int cpu = smp_processor_id();
diff --git a/kernel/user.c b/kernel/user.c
index 75774ce..b143217 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -155,11 +155,11 @@
if (!up)
return;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
if (atomic_dec_and_lock(&up->__count, &uidhash_lock))
free_user(up, flags);
else
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
struct user_struct *alloc_uid(kuid_t uid)
diff --git a/kernel/wait-simple.c b/kernel/wait-simple.c
new file mode 100644
index 0000000..7dfa86d
--- /dev/null
+++ b/kernel/wait-simple.c
@@ -0,0 +1,115 @@
+/*
+ * Simple waitqueues without fancy flags and callbacks
+ *
+ * (C) 2011 Thomas Gleixner <tglx@linutronix.de>
+ *
+ * Based on kernel/wait.c
+ *
+ * For licencing details see kernel-base/COPYING
+ */
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/wait-simple.h>
+
+/* Adds w to head->list. Must be called with head->lock locked. */
+static inline void __swait_enqueue(struct swait_head *head, struct swaiter *w)
+{
+ list_add(&w->node, &head->list);
+ /* We can't let the condition leak before the setting of head */
+ smp_mb();
+}
+
+/* Removes w from head->list. Must be called with head->lock locked. */
+static inline void __swait_dequeue(struct swaiter *w)
+{
+ list_del_init(&w->node);
+}
+
+void __init_swait_head(struct swait_head *head, struct lock_class_key *key)
+{
+ raw_spin_lock_init(&head->lock);
+ lockdep_set_class(&head->lock, key);
+ INIT_LIST_HEAD(&head->list);
+}
+EXPORT_SYMBOL(__init_swait_head);
+
+void swait_prepare_locked(struct swait_head *head, struct swaiter *w)
+{
+ w->task = current;
+ if (list_empty(&w->node))
+ __swait_enqueue(head, w);
+}
+
+void swait_prepare(struct swait_head *head, struct swaiter *w, int state)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&head->lock, flags);
+ swait_prepare_locked(head, w);
+ __set_current_state(state);
+ raw_spin_unlock_irqrestore(&head->lock, flags);
+}
+EXPORT_SYMBOL(swait_prepare);
+
+void swait_finish_locked(struct swait_head *head, struct swaiter *w)
+{
+ __set_current_state(TASK_RUNNING);
+ if (w->task)
+ __swait_dequeue(w);
+}
+
+void swait_finish(struct swait_head *head, struct swaiter *w)
+{
+ unsigned long flags;
+
+ __set_current_state(TASK_RUNNING);
+ if (w->task) {
+ raw_spin_lock_irqsave(&head->lock, flags);
+ __swait_dequeue(w);
+ raw_spin_unlock_irqrestore(&head->lock, flags);
+ }
+}
+EXPORT_SYMBOL(swait_finish);
+
+unsigned int
+__swait_wake_locked(struct swait_head *head, unsigned int state, unsigned int num)
+{
+ struct swaiter *curr, *next;
+ int woken = 0;
+
+ list_for_each_entry_safe(curr, next, &head->list, node) {
+ if (wake_up_state(curr->task, state)) {
+ __swait_dequeue(curr);
+ /*
+ * The waiting task can free the waiter as
+ * soon as curr->task = NULL is written,
+ * without taking any locks. A memory barrier
+ * is required here to prevent the following
+ * store to curr->task from getting ahead of
+ * the dequeue operation.
+ */
+ smp_wmb();
+ curr->task = NULL;
+ if (++woken == num)
+ break;
+ }
+ }
+ return woken;
+}
+
+unsigned int
+__swait_wake(struct swait_head *head, unsigned int state, unsigned int num)
+{
+ unsigned long flags;
+ int woken;
+
+ if (!swaitqueue_active(head))
+ return 0;
+
+ raw_spin_lock_irqsave(&head->lock, flags);
+ woken = __swait_wake_locked(head, state, num);
+ raw_spin_unlock_irqrestore(&head->lock, flags);
+ return woken;
+}
+EXPORT_SYMBOL(__swait_wake);
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 4431610..870b748 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -205,6 +205,8 @@
#ifdef CONFIG_HARDLOCKUP_DETECTOR
+static DEFINE_RAW_SPINLOCK(watchdog_output_lock);
+
static struct perf_event_attr wd_hw_attr = {
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
@@ -239,10 +241,19 @@
if (__this_cpu_read(hard_watchdog_warn) == true)
return;
- if (hardlockup_panic)
+ /*
+ * If early-printk is enabled then make sure we do not
+ * lock up in printk() and kill console logging:
+ */
+ printk_kill();
+
+ if (hardlockup_panic) {
panic("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
- else
+ } else {
+ raw_spin_lock(&watchdog_output_lock);
WARN(1, "Watchdog detected hard LOCKUP on cpu %d", this_cpu);
+ raw_spin_unlock(&watchdog_output_lock);
+ }
__this_cpu_write(hard_watchdog_warn, true);
return;
@@ -346,6 +357,7 @@
/* kick off the timer for the hardlockup detector */
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer->function = watchdog_timer_fn;
+ hrtimer->irqsafe = 1;
/* Enable the perf event */
watchdog_nmi_enable(cpu);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 2bc1257..6d36faa 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -48,6 +48,8 @@
#include <linux/nodemask.h>
#include <linux/moduleparam.h>
#include <linux/uaccess.h>
+#include <linux/locallock.h>
+#include <linux/delay.h>
#include "workqueue_internal.h"
@@ -124,16 +126,21 @@
* cpu or grabbing pool->lock is enough for read access. If
* POOL_DISASSOCIATED is set, it's identical to L.
*
+ * On RT we need the extra protection via rt_lock_idle_list() for
+ * the list manipulations against read access from
+ * wq_worker_sleeping(). All other places are nicely serialized via
+ * pool->lock.
+ *
* MG: pool->manager_mutex and pool->lock protected. Writes require both
* locks. Reads can happen under either lock.
*
* PL: wq_pool_mutex protected.
*
- * PR: wq_pool_mutex protected for writes. Sched-RCU protected for reads.
+ * PR: wq_pool_mutex protected for writes. RCU protected for reads.
*
* WQ: wq->mutex protected.
*
- * WR: wq->mutex protected for writes. Sched-RCU protected for reads.
+ * WR: wq->mutex protected for writes. RCU protected for reads.
*
* MD: wq_mayday_lock protected.
*/
@@ -178,7 +185,7 @@
atomic_t nr_running ____cacheline_aligned_in_smp;
/*
- * Destruction of pool is sched-RCU protected to allow dereferences
+ * Destruction of pool is RCU protected to allow dereferences
* from get_work_pool().
*/
struct rcu_head rcu;
@@ -207,7 +214,7 @@
/*
* Release of unbound pwq is punted to system_wq. See put_pwq()
* and pwq_unbound_release_workfn() for details. pool_workqueue
- * itself is also sched-RCU protected so that the first pwq can be
+ * itself is also RCU protected so that the first pwq can be
* determined without grabbing wq->mutex.
*/
struct work_struct unbound_release_work;
@@ -323,6 +330,8 @@
struct workqueue_struct *system_freezable_power_efficient_wq __read_mostly;
EXPORT_SYMBOL_GPL(system_freezable_power_efficient_wq);
+static DEFINE_LOCAL_IRQ_LOCK(pendingb_lock);
+
static int worker_thread(void *__worker);
static void copy_workqueue_attrs(struct workqueue_attrs *to,
const struct workqueue_attrs *from);
@@ -331,14 +340,14 @@
#include <trace/events/workqueue.h>
#define assert_rcu_or_pool_mutex() \
- rcu_lockdep_assert(rcu_read_lock_sched_held() || \
+ rcu_lockdep_assert(rcu_read_lock_held() || \
lockdep_is_held(&wq_pool_mutex), \
- "sched RCU or wq_pool_mutex should be held")
+ "RCU or wq_pool_mutex should be held")
#define assert_rcu_or_wq_mutex(wq) \
- rcu_lockdep_assert(rcu_read_lock_sched_held() || \
+ rcu_lockdep_assert(rcu_read_lock_held() || \
lockdep_is_held(&wq->mutex), \
- "sched RCU or wq->mutex should be held")
+ "RCU or wq->mutex should be held")
#ifdef CONFIG_LOCKDEP
#define assert_manager_or_pool_lock(pool) \
@@ -360,7 +369,7 @@
* @pool: iteration cursor
* @pi: integer used for iteration
*
- * This must be called either with wq_pool_mutex held or sched RCU read
+ * This must be called either with wq_pool_mutex held or RCU read
* locked. If the pool needs to be used beyond the locking in effect, the
* caller is responsible for guaranteeing that the pool stays online.
*
@@ -393,7 +402,7 @@
* @pwq: iteration cursor
* @wq: the target workqueue
*
- * This must be called either with wq->mutex held or sched RCU read locked.
+ * This must be called either with wq->mutex held or RCU read locked.
* If the pwq needs to be used beyond the locking in effect, the caller is
* responsible for guaranteeing that the pwq stays online.
*
@@ -405,6 +414,31 @@
if (({ assert_rcu_or_wq_mutex(wq); false; })) { } \
else
+#ifdef CONFIG_PREEMPT_RT_BASE
+static inline void rt_lock_idle_list(struct worker_pool *pool)
+{
+ preempt_disable();
+}
+static inline void rt_unlock_idle_list(struct worker_pool *pool)
+{
+ preempt_enable();
+}
+static inline void sched_lock_idle_list(struct worker_pool *pool) { }
+static inline void sched_unlock_idle_list(struct worker_pool *pool) { }
+#else
+static inline void rt_lock_idle_list(struct worker_pool *pool) { }
+static inline void rt_unlock_idle_list(struct worker_pool *pool) { }
+static inline void sched_lock_idle_list(struct worker_pool *pool)
+{
+ spin_lock_irq(&pool->lock);
+}
+static inline void sched_unlock_idle_list(struct worker_pool *pool)
+{
+ spin_unlock_irq(&pool->lock);
+}
+#endif
+
+
#ifdef CONFIG_DEBUG_OBJECTS_WORK
static struct debug_obj_descr work_debug_descr;
@@ -541,7 +575,7 @@
* @wq: the target workqueue
* @node: the node ID
*
- * This must be called either with pwq_lock held or sched RCU read locked.
+ * This must be called either with pwq_lock held or RCU read locked.
* If the pwq needs to be used beyond the locking in effect, the caller is
* responsible for guaranteeing that the pwq stays online.
*
@@ -674,8 +708,8 @@
* @work: the work item of interest
*
* Pools are created and destroyed under wq_pool_mutex, and allows read
- * access under sched-RCU read lock. As such, this function should be
- * called under wq_pool_mutex or with preemption disabled.
+ * access under RCU read lock. As such, this function should be
+ * called under wq_pool_mutex or inside of a rcu_read_lock() region.
*
* All fields of the returned pool are accessible as long as the above
* mentioned locking is in effect. If the returned pool needs to be used
@@ -826,51 +860,44 @@
*/
static void wake_up_worker(struct worker_pool *pool)
{
- struct worker *worker = first_worker(pool);
+ struct worker *worker;
+
+ rt_lock_idle_list(pool);
+
+ worker = first_worker(pool);
if (likely(worker))
wake_up_process(worker->task);
+
+ rt_unlock_idle_list(pool);
}
/**
- * wq_worker_waking_up - a worker is waking up
- * @task: task waking up
- * @cpu: CPU @task is waking up to
+ * wq_worker_running - a worker is running again
+ * @task: task returning from sleep
*
- * This function is called during try_to_wake_up() when a worker is
- * being awoken.
- *
- * CONTEXT:
- * spin_lock_irq(rq->lock)
+ * This function is called when a worker returns from schedule()
*/
-void wq_worker_waking_up(struct task_struct *task, int cpu)
+void wq_worker_running(struct task_struct *task)
{
struct worker *worker = kthread_data(task);
- if (!(worker->flags & WORKER_NOT_RUNNING)) {
- WARN_ON_ONCE(worker->pool->cpu != cpu);
+ if (!worker->sleeping)
+ return;
+ if (!(worker->flags & WORKER_NOT_RUNNING))
atomic_inc(&worker->pool->nr_running);
- }
+ worker->sleeping = 0;
}
/**
* wq_worker_sleeping - a worker is going to sleep
* @task: task going to sleep
- * @cpu: CPU in question, must be the current CPU number
- *
- * This function is called during schedule() when a busy worker is
- * going to sleep. Worker on the same cpu can be woken up by
- * returning pointer to its task.
- *
- * CONTEXT:
- * spin_lock_irq(rq->lock)
- *
- * Return:
- * Worker task on @cpu to wake up, %NULL if none.
+ * This function is called from schedule() when a busy worker is
+ * going to sleep.
*/
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
+void wq_worker_sleeping(struct task_struct *task)
{
- struct worker *worker = kthread_data(task), *to_wakeup = NULL;
+ struct worker *worker = kthread_data(task);
struct worker_pool *pool;
/*
@@ -879,29 +906,26 @@
* checking NOT_RUNNING.
*/
if (worker->flags & WORKER_NOT_RUNNING)
- return NULL;
+ return;
pool = worker->pool;
- /* this can only happen on the local cpu */
- if (WARN_ON_ONCE(cpu != raw_smp_processor_id()))
- return NULL;
+ if (WARN_ON_ONCE(worker->sleeping))
+ return;
+
+ worker->sleeping = 1;
/*
* The counterpart of the following dec_and_test, implied mb,
* worklist not empty test sequence is in insert_work().
* Please read comment there.
- *
- * NOT_RUNNING is clear. This means that we're bound to and
- * running on the local cpu w/ rq lock held and preemption
- * disabled, which in turn means that none else could be
- * manipulating idle_list, so dereferencing idle_list without pool
- * lock is safe.
*/
if (atomic_dec_and_test(&pool->nr_running) &&
- !list_empty(&pool->worklist))
- to_wakeup = first_worker(pool);
- return to_wakeup ? to_wakeup->task : NULL;
+ !list_empty(&pool->worklist)) {
+ sched_lock_idle_list(pool);
+ wake_up_worker(pool);
+ sched_unlock_idle_list(pool);
+ }
}
/**
@@ -1108,12 +1132,14 @@
{
if (pwq) {
/*
- * As both pwqs and pools are sched-RCU protected, the
+ * As both pwqs and pools are RCU protected, the
* following lock operations are safe.
*/
- spin_lock_irq(&pwq->pool->lock);
+ rcu_read_lock();
+ local_spin_lock_irq(pendingb_lock, &pwq->pool->lock);
put_pwq(pwq);
- spin_unlock_irq(&pwq->pool->lock);
+ local_spin_unlock_irq(pendingb_lock, &pwq->pool->lock);
+ rcu_read_unlock();
}
}
@@ -1215,7 +1241,7 @@
struct worker_pool *pool;
struct pool_workqueue *pwq;
- local_irq_save(*flags);
+ local_lock_irqsave(pendingb_lock, *flags);
/* try to steal the timer if it exists */
if (is_dwork) {
@@ -1234,6 +1260,7 @@
if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work)))
return 0;
+ rcu_read_lock();
/*
* The queueing is in progress, or it is already queued. Try to
* steal it from ->worklist without clearing WORK_STRUCT_PENDING.
@@ -1272,14 +1299,16 @@
set_work_pool_and_keep_pending(work, pool->id);
spin_unlock(&pool->lock);
+ rcu_read_unlock();
return 1;
}
spin_unlock(&pool->lock);
fail:
- local_irq_restore(*flags);
+ rcu_read_unlock();
+ local_unlock_irqrestore(pendingb_lock, *flags);
if (work_is_canceling(work))
return -ENOENT;
- cpu_relax();
+ cpu_chill();
return -EAGAIN;
}
@@ -1348,7 +1377,7 @@
* queued or lose PENDING. Grabbing PENDING and queueing should
* happen with IRQ disabled.
*/
- WARN_ON_ONCE(!irqs_disabled());
+ WARN_ON_ONCE_NONRT(!irqs_disabled());
debug_work_activate(work);
@@ -1356,6 +1385,8 @@
if (unlikely(wq->flags & __WQ_DRAINING) &&
WARN_ON_ONCE(!is_chained_work(wq)))
return;
+
+ rcu_read_lock();
retry:
if (req_cpu == WORK_CPU_UNBOUND)
cpu = raw_smp_processor_id();
@@ -1412,10 +1443,8 @@
/* pwq determined, queue */
trace_workqueue_queue_work(req_cpu, pwq, work);
- if (WARN_ON(!list_empty(&work->entry))) {
- spin_unlock(&pwq->pool->lock);
- return;
- }
+ if (WARN_ON(!list_empty(&work->entry)))
+ goto out;
pwq->nr_in_flight[pwq->work_color]++;
work_flags = work_color_to_flags(pwq->work_color);
@@ -1431,7 +1460,9 @@
insert_work(pwq, work, worklist, work_flags);
+out:
spin_unlock(&pwq->pool->lock);
+ rcu_read_unlock();
}
/**
@@ -1451,14 +1482,14 @@
bool ret = false;
unsigned long flags;
- local_irq_save(flags);
+ local_lock_irqsave(pendingb_lock,flags);
if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
__queue_work(cpu, wq, work);
ret = true;
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(pendingb_lock, flags);
return ret;
}
EXPORT_SYMBOL(queue_work_on);
@@ -1525,14 +1556,14 @@
unsigned long flags;
/* read the comment in __queue_work() */
- local_irq_save(flags);
+ local_lock_irqsave(pendingb_lock, flags);
if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
__queue_delayed_work(cpu, wq, dwork, delay);
ret = true;
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(pendingb_lock, flags);
return ret;
}
EXPORT_SYMBOL(queue_delayed_work_on);
@@ -1567,7 +1598,7 @@
if (likely(ret >= 0)) {
__queue_delayed_work(cpu, wq, dwork, delay);
- local_irq_restore(flags);
+ local_unlock_irqrestore(pendingb_lock, flags);
}
/* -ENOENT from try_to_grab_pending() becomes %true */
@@ -1600,7 +1631,9 @@
worker->last_active = jiffies;
/* idle_list is LIFO */
+ rt_lock_idle_list(pool);
list_add(&worker->entry, &pool->idle_list);
+ rt_unlock_idle_list(pool);
if (too_many_workers(pool) && !timer_pending(&pool->idle_timer))
mod_timer(&pool->idle_timer, jiffies + IDLE_WORKER_TIMEOUT);
@@ -1633,7 +1666,9 @@
return;
worker_clr_flags(worker, WORKER_IDLE);
pool->nr_idle--;
+ rt_lock_idle_list(pool);
list_del_init(&worker->entry);
+ rt_unlock_idle_list(pool);
}
/**
@@ -1878,7 +1913,9 @@
*/
get_task_struct(worker->task);
+ rt_lock_idle_list(pool);
list_del_init(&worker->entry);
+ rt_unlock_idle_list(pool);
worker->flags |= WORKER_DIE;
idr_remove(&pool->worker_idr, worker->id);
@@ -2845,14 +2882,14 @@
might_sleep();
- local_irq_disable();
+ rcu_read_lock();
pool = get_work_pool(work);
if (!pool) {
- local_irq_enable();
+ rcu_read_unlock();
return false;
}
- spin_lock(&pool->lock);
+ spin_lock_irq(&pool->lock);
/* see the comment in try_to_grab_pending() with the same code */
pwq = get_work_pwq(work);
if (pwq) {
@@ -2879,10 +2916,11 @@
else
lock_map_acquire_read(&pwq->wq->lockdep_map);
lock_map_release(&pwq->wq->lockdep_map);
-
+ rcu_read_unlock();
return true;
already_gone:
spin_unlock_irq(&pool->lock);
+ rcu_read_unlock();
return false;
}
@@ -2974,7 +3012,7 @@
/* tell other tasks trying to grab @work to back off */
mark_work_canceling(work);
- local_irq_restore(flags);
+ local_unlock_irqrestore(pendingb_lock, flags);
flush_work(work);
clear_work_data(work);
@@ -3029,10 +3067,10 @@
*/
bool flush_delayed_work(struct delayed_work *dwork)
{
- local_irq_disable();
+ local_lock_irq(pendingb_lock);
if (del_timer_sync(&dwork->timer))
__queue_work(dwork->cpu, dwork->wq, &dwork->work);
- local_irq_enable();
+ local_unlock_irq(pendingb_lock);
return flush_work(&dwork->work);
}
EXPORT_SYMBOL(flush_delayed_work);
@@ -3067,7 +3105,7 @@
set_work_pool_and_clear_pending(&dwork->work,
get_work_pool_id(&dwork->work));
- local_irq_restore(flags);
+ local_unlock_irqrestore(pendingb_lock, flags);
return ret;
}
EXPORT_SYMBOL(cancel_delayed_work);
@@ -3253,7 +3291,8 @@
const char *delim = "";
int node, written = 0;
- rcu_read_lock_sched();
+ get_online_cpus();
+ rcu_read_lock();
for_each_node(node) {
written += scnprintf(buf + written, PAGE_SIZE - written,
"%s%d:%d", delim, node,
@@ -3261,7 +3300,8 @@
delim = " ";
}
written += scnprintf(buf + written, PAGE_SIZE - written, "\n");
- rcu_read_unlock_sched();
+ rcu_read_unlock();
+ put_online_cpus();
return written;
}
@@ -3628,7 +3668,7 @@
* put_unbound_pool - put a worker_pool
* @pool: worker_pool to put
*
- * Put @pool. If its refcnt reaches zero, it gets destroyed in sched-RCU
+ * Put @pool. If its refcnt reaches zero, it gets destroyed in RCU
* safe manner. get_unbound_pool() calls this function on its failure path
* and this function should be able to release pools which went through,
* successfully or not, init_worker_pool().
@@ -3675,8 +3715,8 @@
del_timer_sync(&pool->idle_timer);
del_timer_sync(&pool->mayday_timer);
- /* sched-RCU protected to allow dereferences from get_work_pool() */
- call_rcu_sched(&pool->rcu, rcu_free_pool);
+ /* RCU protected to allow dereferences from get_work_pool() */
+ call_rcu(&pool->rcu, rcu_free_pool);
}
/**
@@ -3789,7 +3829,7 @@
put_unbound_pool(pool);
mutex_unlock(&wq_pool_mutex);
- call_rcu_sched(&pwq->rcu, rcu_free_pwq);
+ call_rcu(&pwq->rcu, rcu_free_pwq);
/*
* If we're the last pwq going away, @wq is already dead and no one
@@ -4503,7 +4543,8 @@
struct pool_workqueue *pwq;
bool ret;
- rcu_read_lock_sched();
+ rcu_read_lock();
+ preempt_disable();
if (cpu == WORK_CPU_UNBOUND)
cpu = smp_processor_id();
@@ -4514,7 +4555,8 @@
pwq = unbound_pwq_by_node(wq, cpu_to_node(cpu));
ret = !list_empty(&pwq->delayed_works);
- rcu_read_unlock_sched();
+ preempt_enable();
+ rcu_read_unlock();
return ret;
}
@@ -4540,16 +4582,15 @@
if (work_pending(work))
ret |= WORK_BUSY_PENDING;
- local_irq_save(flags);
+ rcu_read_lock();
pool = get_work_pool(work);
if (pool) {
- spin_lock(&pool->lock);
+ spin_lock_irqsave(&pool->lock, flags);
if (find_worker_executing_work(pool, work))
ret |= WORK_BUSY_RUNNING;
- spin_unlock(&pool->lock);
+ spin_unlock_irqrestore(&pool->lock, flags);
}
- local_irq_restore(flags);
-
+ rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(work_busy);
@@ -5002,16 +5043,16 @@
* nr_active is monotonically decreasing. It's safe
* to peek without lock.
*/
- rcu_read_lock_sched();
+ rcu_read_lock();
for_each_pwq(pwq, wq) {
WARN_ON_ONCE(pwq->nr_active < 0);
if (pwq->nr_active) {
busy = true;
- rcu_read_unlock_sched();
+ rcu_read_unlock();
goto out_unlock;
}
}
- rcu_read_unlock_sched();
+ rcu_read_unlock();
}
out_unlock:
mutex_unlock(&wq_pool_mutex);
diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h
index 7e2204d..2bb5b5a 100644
--- a/kernel/workqueue_internal.h
+++ b/kernel/workqueue_internal.h
@@ -41,6 +41,7 @@
unsigned long last_active; /* L: last active timestamp */
unsigned int flags; /* X: flags */
int id; /* I: worker id */
+ int sleeping; /* None */
/*
* Opaque string set with work_set_desc(). Printed out with task
@@ -66,7 +67,7 @@
* Scheduler hooks for concurrency managed workqueue. Only to be used from
* sched/core.c and workqueue.c.
*/
-void wq_worker_waking_up(struct task_struct *task, int cpu);
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu);
+void wq_worker_running(struct task_struct *task);
+void wq_worker_sleeping(struct task_struct *task);
#endif /* _KERNEL_WORKQUEUE_INTERNAL_H */
diff --git a/lib/Kconfig b/lib/Kconfig
index b3c8be0..eee9e09 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -57,6 +57,7 @@
depends on !GENERIC_LOCKBREAK
depends on !DEBUG_SPINLOCK
depends on !DEBUG_LOCK_ALLOC
+ depends on !PREEMPT_RT_BASE
config CRC_CCITT
tristate "CRC-CCITT functions"
@@ -343,6 +344,7 @@
config CPUMASK_OFFSTACK
bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
+ depends on !PREEMPT_RT_FULL
help
Use dynamic allocation for cpumask_var_t, instead of putting
them on the stack. This is a bit more expensive, but avoids
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 094f315..bde5dd2 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -597,7 +597,7 @@
config DEBUG_SHIRQ
bool "Debug shared IRQ handlers"
- depends on DEBUG_KERNEL
+ depends on DEBUG_KERNEL && !PREEMPT_RT_BASE
help
Enable this to generate a spurious interrupt as soon as a shared
interrupt handler is registered, and just before one is deregistered.
diff --git a/lib/Makefile b/lib/Makefile
index 6af6fbb..4461595 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -43,8 +43,11 @@
obj-$(CONFIG_CHECK_SIGNATURE) += check_signature.o
obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
+
+ifneq ($(CONFIG_PREEMPT_RT_FULL),y)
lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
+endif
lib-$(CONFIG_PERCPU_RWSEM) += percpu-rwsem.o
GCOV_PROFILE_hweight.o := n
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index bf2c8b1..1ac2049 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -308,7 +308,10 @@
struct debug_obj *obj;
unsigned long flags;
- fill_pool();
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (preempt_count() == 0 && !irqs_disabled())
+#endif
+ fill_pool();
db = get_bucket((unsigned long) addr);
diff --git a/lib/idr.c b/lib/idr.c
index 674c30b..c9a8dbc 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -37,6 +37,7 @@
#include <linux/spinlock.h>
#include <linux/percpu.h>
#include <linux/hardirq.h>
+#include <linux/locallock.h>
#define MAX_IDR_SHIFT (sizeof(int) * 8 - 1)
#define MAX_IDR_BIT (1U << MAX_IDR_SHIFT)
@@ -389,6 +390,36 @@
}
EXPORT_SYMBOL(__idr_get_new_above);
+#ifdef CONFIG_PREEMPT_RT_FULL
+static DEFINE_LOCAL_IRQ_LOCK(idr_lock);
+
+static inline void idr_preload_lock(void)
+{
+ local_lock(idr_lock);
+}
+
+static inline void idr_preload_unlock(void)
+{
+ local_unlock(idr_lock);
+}
+
+void idr_preload_end(void)
+{
+ idr_preload_unlock();
+}
+EXPORT_SYMBOL(idr_preload_end);
+#else
+static inline void idr_preload_lock(void)
+{
+ preempt_disable();
+}
+
+static inline void idr_preload_unlock(void)
+{
+ preempt_enable();
+}
+#endif
+
/**
* idr_preload - preload for idr_alloc()
* @gfp_mask: allocation mask to use for preloading
@@ -423,7 +454,7 @@
WARN_ON_ONCE(in_interrupt());
might_sleep_if(gfp_mask & __GFP_WAIT);
- preempt_disable();
+ idr_preload_lock();
/*
* idr_alloc() is likely to succeed w/o full idr_layer buffer and
@@ -435,9 +466,9 @@
while (__this_cpu_read(idr_preload_cnt) < MAX_IDR_FREE) {
struct idr_layer *new;
- preempt_enable();
+ idr_preload_unlock();
new = kmem_cache_zalloc(idr_layer_cache, gfp_mask);
- preempt_disable();
+ idr_preload_lock();
if (!new)
break;
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index 6dc09d8..bd3eaf8 100644
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -590,6 +590,8 @@
#include "locking-selftest-spin-hardirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_spin)
+#ifndef CONFIG_PREEMPT_RT_FULL
+
#include "locking-selftest-rlock-hardirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_rlock)
@@ -605,9 +607,12 @@
#include "locking-selftest-wlock-softirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_wlock)
+#endif
+
#undef E1
#undef E2
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* Enabling hardirqs with a softirq-safe lock held:
*/
@@ -640,6 +645,8 @@
#undef E1
#undef E2
+#endif
+
/*
* Enabling irqs with an irq-safe lock held:
*/
@@ -663,6 +670,8 @@
#include "locking-selftest-spin-hardirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_spin)
+#ifndef CONFIG_PREEMPT_RT_FULL
+
#include "locking-selftest-rlock-hardirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_rlock)
@@ -678,6 +687,8 @@
#include "locking-selftest-wlock-softirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_wlock)
+#endif
+
#undef E1
#undef E2
@@ -709,6 +720,8 @@
#include "locking-selftest-spin-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_spin)
+#ifndef CONFIG_PREEMPT_RT_FULL
+
#include "locking-selftest-rlock-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_rlock)
@@ -724,6 +737,8 @@
#include "locking-selftest-wlock-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_wlock)
+#endif
+
#undef E1
#undef E2
#undef E3
@@ -757,6 +772,8 @@
#include "locking-selftest-spin-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_spin)
+#ifndef CONFIG_PREEMPT_RT_FULL
+
#include "locking-selftest-rlock-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_rlock)
@@ -772,10 +789,14 @@
#include "locking-selftest-wlock-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_wlock)
+#endif
+
#undef E1
#undef E2
#undef E3
+#ifndef CONFIG_PREEMPT_RT_FULL
+
/*
* read-lock / write-lock irq inversion.
*
@@ -838,6 +859,10 @@
#undef E2
#undef E3
+#endif
+
+#ifndef CONFIG_PREEMPT_RT_FULL
+
/*
* read-lock / write-lock recursion that is actually safe.
*/
@@ -876,6 +901,8 @@
#undef E2
#undef E3
+#endif
+
/*
* read-lock / write-lock recursion that is unsafe.
*/
@@ -1858,6 +1885,7 @@
printk(" --------------------------------------------------------------------------\n");
+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* irq-context testcases:
*/
@@ -1870,6 +1898,28 @@
DO_TESTCASE_6x2("irq read-recursion", irq_read_recursion);
// DO_TESTCASE_6x2B("irq read-recursion #2", irq_read_recursion2);
+#else
+ /* On -rt, we only do hardirq context test for raw spinlock */
+ DO_TESTCASE_1B("hard-irqs-on + irq-safe-A", irqsafe1_hard_spin, 12);
+ DO_TESTCASE_1B("hard-irqs-on + irq-safe-A", irqsafe1_hard_spin, 21);
+
+ DO_TESTCASE_1B("hard-safe-A + irqs-on", irqsafe2B_hard_spin, 12);
+ DO_TESTCASE_1B("hard-safe-A + irqs-on", irqsafe2B_hard_spin, 21);
+
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 123);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 132);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 213);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 231);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 312);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 321);
+
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 123);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 132);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 213);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 231);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 312);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 321);
+#endif
ww_tests();
diff --git a/lib/percpu-rwsem.c b/lib/percpu-rwsem.c
index 652a8ee..2db0f42 100644
--- a/lib/percpu-rwsem.c
+++ b/lib/percpu-rwsem.c
@@ -84,8 +84,12 @@
down_read(&brw->rw_sem);
atomic_inc(&brw->slow_read_ctr);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ up_read(&brw->rw_sem);
+#else
/* avoid up_read()->rwsem_release() */
__up_read(&brw->rw_sem);
+#endif
}
void percpu_up_read(struct percpu_rw_semaphore *brw)
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 50a9a1c..1236857 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -33,7 +33,7 @@
#include <linux/bitops.h>
#include <linux/rcupdate.h>
#include <linux/hardirq.h> /* in_interrupt() */
-
+#include <linux/locallock.h>
#ifdef __KERNEL__
#define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6)
@@ -94,6 +94,7 @@
struct radix_tree_node *nodes[RADIX_TREE_PRELOAD_SIZE];
};
static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, };
+static DEFINE_LOCAL_IRQ_LOCK(radix_tree_preloads_lock);
static inline void *ptr_to_indirect(void *ptr)
{
@@ -221,12 +222,13 @@
* succeed in getting a node here (and never reach
* kmem_cache_alloc)
*/
- rtp = &__get_cpu_var(radix_tree_preloads);
+ rtp = &get_locked_var(radix_tree_preloads_lock, radix_tree_preloads);
if (rtp->nr) {
ret = rtp->nodes[rtp->nr - 1];
rtp->nodes[rtp->nr - 1] = NULL;
rtp->nr--;
}
+ put_locked_var(radix_tree_preloads_lock, radix_tree_preloads);
}
if (ret == NULL)
ret = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
@@ -276,14 +278,14 @@
struct radix_tree_node *node;
int ret = -ENOMEM;
- preempt_disable();
+ local_lock(radix_tree_preloads_lock);
rtp = &__get_cpu_var(radix_tree_preloads);
while (rtp->nr < ARRAY_SIZE(rtp->nodes)) {
- preempt_enable();
+ local_unlock(radix_tree_preloads_lock);
node = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
if (node == NULL)
goto out;
- preempt_disable();
+ local_lock(radix_tree_preloads_lock);
rtp = &__get_cpu_var(radix_tree_preloads);
if (rtp->nr < ARRAY_SIZE(rtp->nodes))
rtp->nodes[rtp->nr++] = node;
@@ -322,11 +324,17 @@
if (gfp_mask & __GFP_WAIT)
return __radix_tree_preload(gfp_mask);
/* Preloading doesn't help anything with this gfp mask, skip it */
- preempt_disable();
+ local_lock(radix_tree_preloads_lock);
return 0;
}
EXPORT_SYMBOL(radix_tree_maybe_preload);
+void radix_tree_preload_end(void)
+{
+ local_unlock(radix_tree_preloads_lock);
+}
+EXPORT_SYMBOL(radix_tree_preload_end);
+
/*
* Return the maximum key which can be store into a
* radix tree with height HEIGHT.
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index d16fa29..9c1236e 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -582,7 +582,7 @@
flush_kernel_dcache_page(miter->page);
if (miter->__flags & SG_MITER_ATOMIC) {
- WARN_ON_ONCE(preemptible());
+ WARN_ON_ONCE(!pagefault_disabled());
kunmap_atomic(miter->addr);
} else
kunmap(miter->page);
@@ -627,7 +627,7 @@
if (!sg_miter_skip(&miter, skip))
return false;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
while (sg_miter_next(&miter) && offset < buflen) {
unsigned int len;
@@ -644,7 +644,7 @@
sg_miter_stop(&miter);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
return offset;
}
diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c
index 4c0d0e5..dbb1570 100644
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -39,9 +39,9 @@
if (!printk_ratelimit())
goto out_enable;
- printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] "
- "code: %s/%d\n",
- preempt_count() - 1, current->comm, current->pid);
+ printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x %08x] "
+ "code: %s/%d\n", preempt_count() - 1,
+ __migrate_disabled(current), current->comm, current->pid);
print_symbol("caller is %s\n", (long)__builtin_return_address(0));
dump_stack();
diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c
index 0374a59..9497033 100644
--- a/lib/spinlock_debug.c
+++ b/lib/spinlock_debug.c
@@ -31,6 +31,7 @@
EXPORT_SYMBOL(__raw_spin_lock_init);
+#ifndef CONFIG_PREEMPT_RT_FULL
void __rwlock_init(rwlock_t *lock, const char *name,
struct lock_class_key *key)
{
@@ -48,6 +49,7 @@
}
EXPORT_SYMBOL(__rwlock_init);
+#endif
static void spin_dump(raw_spinlock_t *lock, const char *msg)
{
@@ -159,6 +161,7 @@
arch_spin_unlock(&lock->raw_lock);
}
+#ifndef CONFIG_PREEMPT_RT_FULL
static void rwlock_bug(rwlock_t *lock, const char *msg)
{
if (!debug_locks_off())
@@ -300,3 +303,5 @@
debug_write_unlock(lock);
arch_write_unlock(&lock->raw_lock);
}
+
+#endif
diff --git a/localversion-rt b/localversion-rt
new file mode 100644
index 0000000..8de2532
--- /dev/null
+++ b/localversion-rt
@@ -0,0 +1 @@
+-rt98
diff --git a/mm/Kconfig b/mm/Kconfig
index 2a092f5..b183a91 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -387,7 +387,7 @@
config TRANSPARENT_HUGEPAGE
bool "Transparent Hugepage Support"
- depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE
+ depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE && !PREEMPT_RT_FULL
select COMPACTION
help
Transparent Hugepages allows the kernel to use huge pages and
diff --git a/mm/bounce.c b/mm/bounce.c
index 5a7d58f..b09bb4e 100644
--- a/mm/bounce.c
+++ b/mm/bounce.c
@@ -51,11 +51,11 @@
unsigned long flags;
unsigned char *vto;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
vto = kmap_atomic(to->bv_page);
memcpy(vto + to->bv_offset, vfrom, to->bv_len);
kunmap_atomic(vto);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}
#else /* CONFIG_HIGHMEM */
diff --git a/mm/highmem.c b/mm/highmem.c
index b32b70c..b1c7d43 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -29,10 +29,11 @@
#include <linux/kgdb.h>
#include <asm/tlbflush.h>
-
+#ifndef CONFIG_PREEMPT_RT_FULL
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
DEFINE_PER_CPU(int, __kmap_atomic_idx);
#endif
+#endif
/*
* Virtual_count is not a pure "count".
@@ -47,8 +48,9 @@
unsigned long totalhigh_pages __read_mostly;
EXPORT_SYMBOL(totalhigh_pages);
-
+#ifndef CONFIG_PREEMPT_RT_FULL
EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
+#endif
unsigned int nr_free_highpages (void)
{
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0154a00..b2a94b3 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2474,14 +2474,17 @@
*/
static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
{
- struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
+ struct memcg_stock_pcp *stock;
+ int cpu = get_cpu_light();
+
+ stock = &per_cpu(memcg_stock, cpu);
if (stock->cached != memcg) { /* reset if necessary */
drain_stock(stock);
stock->cached = memcg;
}
stock->nr_pages += nr_pages;
- put_cpu_var(memcg_stock);
+ put_cpu_light();
}
/*
@@ -2495,7 +2498,7 @@
/* Notify other cpus that system-wide "drain" is running */
get_online_cpus();
- curcpu = get_cpu();
+ curcpu = get_cpu_light();
for_each_online_cpu(cpu) {
struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
struct mem_cgroup *memcg;
@@ -2512,7 +2515,7 @@
schedule_work_on(cpu, &stock->work);
}
}
- put_cpu();
+ put_cpu_light();
if (!sync)
goto out;
diff --git a/mm/memory.c b/mm/memory.c
index f574426..3efc668 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3754,6 +3754,32 @@
return 0;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+void pagefault_disable(void)
+{
+ migrate_disable();
+ current->pagefault_disabled++;
+ /*
+ * make sure to have issued the store before a pagefault
+ * can hit.
+ */
+ barrier();
+}
+EXPORT_SYMBOL(pagefault_disable);
+
+void pagefault_enable(void)
+{
+ /*
+ * make sure to issue those last loads/stores before enabling
+ * the pagefault handler again.
+ */
+ barrier();
+ current->pagefault_disabled--;
+ migrate_enable();
+}
+EXPORT_SYMBOL(pagefault_enable);
+#endif
+
/*
* By the time we get here, we already hold the mm semaphore
*/
@@ -4340,3 +4366,35 @@
}
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
+
+#if defined(CONFIG_PREEMPT_RT_FULL) && (USE_SPLIT_PTLOCKS > 0)
+/*
+ * Heinous hack, relies on the caller doing something like:
+ *
+ * pte = alloc_pages(PGALLOC_GFP, 0);
+ * if (pte)
+ * pgtable_page_ctor(pte);
+ * return pte;
+ *
+ * This ensures we release the page and return NULL when the
+ * lock allocation fails.
+ */
+struct page *pte_lock_init(struct page *page)
+{
+ page->ptl = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
+ if (page->ptl) {
+ spin_lock_init(__pte_lockptr(page));
+ } else {
+ __free_page(page);
+ page = NULL;
+ }
+ return page;
+}
+
+void pte_lock_deinit(struct page *page)
+{
+ kfree(page->ptl);
+ page->mapping = NULL;
+}
+
+#endif
diff --git a/mm/mmu_context.c b/mm/mmu_context.c
index 8a8cd02..adfce87 100644
--- a/mm/mmu_context.c
+++ b/mm/mmu_context.c
@@ -23,6 +23,7 @@
struct task_struct *tsk = current;
task_lock(tsk);
+ preempt_disable_rt();
active_mm = tsk->active_mm;
if (active_mm != mm) {
atomic_inc(&mm->mm_count);
@@ -30,6 +31,7 @@
}
tsk->mm = mm;
switch_mm(active_mm, mm, tsk);
+ preempt_enable_rt();
task_unlock(tsk);
if (active_mm != mm)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8927c8d..6a11816 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -61,6 +61,7 @@
#include <linux/page-debug-flags.h>
#include <linux/hugetlb.h>
#include <linux/sched/rt.h>
+#include <linux/locallock.h>
#include <asm/sections.h>
#include <asm/tlbflush.h>
@@ -231,6 +232,18 @@
EXPORT_SYMBOL(nr_online_nodes);
#endif
+static DEFINE_LOCAL_IRQ_LOCK(pa_lock);
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define cpu_lock_irqsave(cpu, flags) \
+ local_lock_irqsave_on(pa_lock, flags, cpu)
+# define cpu_unlock_irqrestore(cpu, flags) \
+ local_unlock_irqrestore_on(pa_lock, flags, cpu)
+#else
+# define cpu_lock_irqsave(cpu, flags) local_irq_save(flags)
+# define cpu_unlock_irqrestore(cpu, flags) local_irq_restore(flags)
+#endif
+
int page_group_by_mobility_disabled __read_mostly;
void set_pageblock_migratetype(struct page *page, int migratetype)
@@ -648,7 +661,7 @@
}
/*
- * Frees a number of pages from the PCP lists
+ * Frees a number of pages which have been collected from the pcp lists.
* Assumes all pages on list are in same zone, and of same order.
* count is the number of pages to free.
*
@@ -659,18 +672,52 @@
* pinned" detection logic.
*/
static void free_pcppages_bulk(struct zone *zone, int count,
- struct per_cpu_pages *pcp)
+ struct list_head *list)
{
- int migratetype = 0;
- int batch_free = 0;
int to_free = count;
unsigned long nr_scanned;
+ unsigned long flags;
- spin_lock(&zone->lock);
+ spin_lock_irqsave(&zone->lock, flags);
nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
if (nr_scanned)
__mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
+ while (!list_empty(list)) {
+ struct page *page = list_first_entry(list, struct page, lru);
+ int mt; /* migratetype of the to-be-freed page */
+
+ /* must delete as __free_one_page list manipulates */
+ list_del(&page->lru);
+
+ mt = get_freepage_migratetype(page);
+ /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
+ __free_one_page(page, page_to_pfn(page), zone, 0, mt);
+ trace_mm_page_pcpu_drain(page, 0, mt);
+ if (likely(!is_migrate_isolate_page(page))) {
+ __mod_zone_page_state(zone, NR_FREE_PAGES, 1);
+ if (is_migrate_cma(mt))
+ __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
+ }
+
+ to_free--;
+ }
+ WARN_ON(to_free != 0);
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+
+/*
+ * Moves a number of pages from the PCP lists to free list which
+ * is freed outside of the locked region.
+ *
+ * Assumes all pages on list are in same zone, and of same order.
+ * count is the number of pages to free.
+ */
+static void isolate_pcp_pages(int to_free, struct per_cpu_pages *src,
+ struct list_head *dst)
+{
+ int migratetype = 0, batch_free = 0;
+
while (to_free) {
struct page *page;
struct list_head *list;
@@ -686,7 +733,7 @@
batch_free++;
if (++migratetype == MIGRATE_PCPTYPES)
migratetype = 0;
- list = &pcp->lists[migratetype];
+ list = &src->lists[migratetype];
} while (list_empty(list));
/* This is the only non-empty list. Free them all. */
@@ -694,23 +741,11 @@
batch_free = to_free;
do {
- int mt; /* migratetype of the to-be-freed page */
-
- page = list_entry(list->prev, struct page, lru);
- /* must delete as __free_one_page list manipulates */
+ page = list_last_entry(list, struct page, lru);
list_del(&page->lru);
- mt = get_freepage_migratetype(page);
- /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
- __free_one_page(page, page_to_pfn(page), zone, 0, mt);
- trace_mm_page_pcpu_drain(page, 0, mt);
- if (likely(!is_migrate_isolate_page(page))) {
- __mod_zone_page_state(zone, NR_FREE_PAGES, 1);
- if (is_migrate_cma(mt))
- __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
- }
+ list_add(&page->lru, dst);
} while (--to_free && --batch_free && !list_empty(list));
}
- spin_unlock(&zone->lock);
}
static void free_one_page(struct zone *zone,
@@ -719,7 +754,9 @@
int migratetype)
{
unsigned long nr_scanned;
- spin_lock(&zone->lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&zone->lock, flags);
nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
if (nr_scanned)
__mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
@@ -727,7 +764,7 @@
__free_one_page(page, pfn, zone, order, migratetype);
if (unlikely(!is_migrate_isolate(migratetype)))
__mod_zone_freepage_state(zone, 1 << order, migratetype);
- spin_unlock(&zone->lock);
+ spin_unlock_irqrestore(&zone->lock, flags);
}
static bool free_pages_prepare(struct page *page, unsigned int order)
@@ -767,11 +804,11 @@
return;
migratetype = get_pfnblock_migratetype(page, pfn);
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
__count_vm_events(PGFREE, 1 << order);
set_freepage_migratetype(page, migratetype);
free_one_page(page_zone(page), page, pfn, order, migratetype);
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
}
void __init __free_pages_bootmem(struct page *page, unsigned int order)
@@ -1236,20 +1273,22 @@
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
{
unsigned long flags;
+ LIST_HEAD(dst);
int to_drain;
unsigned long batch;
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
batch = ACCESS_ONCE(pcp->batch);
if (pcp->count >= batch)
to_drain = batch;
else
to_drain = pcp->count;
if (to_drain > 0) {
- free_pcppages_bulk(zone, to_drain, pcp);
+ isolate_pcp_pages(to_drain, pcp, &dst);
pcp->count -= to_drain;
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
+ free_pcppages_bulk(zone, to_drain, &dst);
}
#endif
@@ -1268,16 +1307,21 @@
for_each_populated_zone(zone) {
struct per_cpu_pageset *pset;
struct per_cpu_pages *pcp;
+ LIST_HEAD(dst);
+ int count;
- local_irq_save(flags);
+ cpu_lock_irqsave(cpu, flags);
pset = per_cpu_ptr(zone->pageset, cpu);
pcp = &pset->pcp;
- if (pcp->count) {
- free_pcppages_bulk(zone, pcp->count, pcp);
+ count = pcp->count;
+ if (count) {
+ isolate_pcp_pages(count, pcp, &dst);
pcp->count = 0;
}
- local_irq_restore(flags);
+ cpu_unlock_irqrestore(cpu, flags);
+ if (count)
+ free_pcppages_bulk(zone, count, &dst);
}
}
@@ -1330,7 +1374,12 @@
else
cpumask_clear_cpu(cpu, &cpus_with_pcps);
}
+#ifndef CONFIG_PREEMPT_RT_BASE
on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, NULL, 1);
+#else
+ for_each_cpu(cpu, &cpus_with_pcps)
+ drain_pages(cpu);
+#endif
}
#ifdef CONFIG_HIBERNATION
@@ -1386,7 +1435,7 @@
migratetype = get_pfnblock_migratetype(page, pfn);
set_freepage_migratetype(page, migratetype);
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
__count_vm_event(PGFREE);
/*
@@ -1412,12 +1461,17 @@
pcp->count++;
if (pcp->count >= pcp->high) {
unsigned long batch = ACCESS_ONCE(pcp->batch);
- free_pcppages_bulk(zone, batch, pcp);
+ LIST_HEAD(dst);
+
+ isolate_pcp_pages(batch, pcp, &dst);
pcp->count -= batch;
+ local_unlock_irqrestore(pa_lock, flags);
+ free_pcppages_bulk(zone, batch, &dst);
+ return;
}
out:
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
}
/*
@@ -1547,7 +1601,7 @@
struct per_cpu_pages *pcp;
struct list_head *list;
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
pcp = &this_cpu_ptr(zone->pageset)->pcp;
list = &pcp->lists[migratetype];
if (list_empty(list)) {
@@ -1579,13 +1633,15 @@
*/
WARN_ON_ONCE(order > 1);
}
- spin_lock_irqsave(&zone->lock, flags);
+ local_spin_lock_irqsave(pa_lock, &zone->lock, flags);
page = __rmqueue(zone, order, migratetype);
- spin_unlock(&zone->lock);
- if (!page)
+ if (!page) {
+ spin_unlock(&zone->lock);
goto failed;
+ }
__mod_zone_freepage_state(zone, -(1 << order),
get_freepage_migratetype(page));
+ spin_unlock(&zone->lock);
}
__mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
@@ -1595,7 +1651,7 @@
__count_zone_vm_events(PGALLOC, zone, 1 << order);
zone_statistics(preferred_zone, zone, gfp_flags);
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
VM_BUG_ON(bad_range(zone, page));
if (prep_new_page(page, order, gfp_flags))
@@ -1603,7 +1659,7 @@
return page;
failed:
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
return NULL;
}
@@ -2322,8 +2378,8 @@
struct page *page;
/* Page migration frees to the PCP lists but we want merging */
- drain_pages(get_cpu());
- put_cpu();
+ drain_pages(get_cpu_light());
+ put_cpu_light();
page = get_page_from_freelist(gfp_mask, nodemask,
order, zonelist, high_zoneidx,
@@ -5533,6 +5589,7 @@
void __init page_alloc_init(void)
{
hotcpu_notifier(page_alloc_cpu_notify, 0);
+ local_irq_lock_init(pa_lock);
}
/*
@@ -6426,7 +6483,7 @@
struct per_cpu_pageset *pset;
/* avoid races with drain_pages() */
- local_irq_save(flags);
+ local_lock_irqsave(pa_lock, flags);
if (zone->pageset != &boot_pageset) {
for_each_online_cpu(cpu) {
pset = per_cpu_ptr(zone->pageset, cpu);
@@ -6435,7 +6492,7 @@
free_percpu(zone->pageset);
zone->pageset = &boot_pageset;
}
- local_irq_restore(flags);
+ local_unlock_irqrestore(pa_lock, flags);
}
#ifdef CONFIG_MEMORY_HOTREMOVE
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index e007236..384518e 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -13,6 +13,14 @@
static unsigned long total_usage;
+static void page_cgroup_lock_init(struct page_cgroup *pc, int nr_pages)
+{
+#ifdef CONFIG_PREEMPT_RT_BASE
+ for (; nr_pages; nr_pages--, pc++)
+ spin_lock_init(&pc->pcg_lock);
+#endif
+}
+
#if !defined(CONFIG_SPARSEMEM)
@@ -60,6 +68,7 @@
return -ENOMEM;
NODE_DATA(nid)->node_page_cgroup = base;
total_usage += table_size;
+ page_cgroup_lock_init(base, nr_pages);
return 0;
}
@@ -150,6 +159,8 @@
return -ENOMEM;
}
+ page_cgroup_lock_init(base, PAGES_PER_SECTION);
+
/*
* The passed "pfn" may not be aligned to SECTION. For the calculation
* we need to apply a mask.
diff --git a/mm/percpu.c b/mm/percpu.c
index 25e2ea5..b96d41d 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -946,6 +946,28 @@
}
EXPORT_SYMBOL_GPL(free_percpu);
+bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr)
+{
+#ifdef CONFIG_SMP
+ const size_t static_size = __per_cpu_end - __per_cpu_start;
+ void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr);
+ unsigned int cpu;
+
+ for_each_possible_cpu(cpu) {
+ void *start = per_cpu_ptr(base, cpu);
+ void *va = (void *)addr;
+
+ if (va >= start && va < start + static_size) {
+ if (can_addr)
+ *can_addr = (unsigned long) (va - start);
+ return true;
+ }
+ }
+#endif
+ /* on UP, can't distinguish from other static vars, always false */
+ return false;
+}
+
/**
* is_kernel_percpu_address - test whether address is from static percpu area
* @addr: address to test
@@ -959,20 +981,7 @@
*/
bool is_kernel_percpu_address(unsigned long addr)
{
-#ifdef CONFIG_SMP
- const size_t static_size = __per_cpu_end - __per_cpu_start;
- void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr);
- unsigned int cpu;
-
- for_each_possible_cpu(cpu) {
- void *start = per_cpu_ptr(base, cpu);
-
- if ((void *)addr >= start && (void *)addr < start + static_size)
- return true;
- }
-#endif
- /* on UP, can't distinguish from other static vars, always false */
- return false;
+ return __is_kernel_percpu_address(addr, NULL);
}
/**
diff --git a/mm/slab.h b/mm/slab.h
index a535033..8ffb287 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -247,7 +247,11 @@
* The slab lists for all objects.
*/
struct kmem_cache_node {
+#ifdef CONFIG_SLUB
+ raw_spinlock_t list_lock;
+#else
spinlock_t list_lock;
+#endif
#ifdef CONFIG_SLAB
struct list_head slabs_partial; /* partial list first, better asm code */
diff --git a/mm/slub.c b/mm/slub.c
index a88d94c..3a5d54e7 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1087,7 +1087,7 @@
{
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
- spin_lock_irqsave(&n->list_lock, *flags);
+ raw_spin_lock_irqsave(&n->list_lock, *flags);
slab_lock(page);
if (!check_slab(s, page))
@@ -1135,7 +1135,7 @@
fail:
slab_unlock(page);
- spin_unlock_irqrestore(&n->list_lock, *flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, *flags);
slab_fix(s, "Object at 0x%p not freed", object);
return NULL;
}
@@ -1270,6 +1270,20 @@
#endif /* CONFIG_SLUB_DEBUG */
+struct slub_free_list {
+ raw_spinlock_t lock;
+ struct list_head list;
+};
+static DEFINE_PER_CPU(struct slub_free_list, slub_free_list);
+
+static void setup_object(struct kmem_cache *s, struct page *page,
+ void *object)
+{
+ setup_object_debug(s, page, object);
+ if (unlikely(s->ctor))
+ s->ctor(object);
+}
+
/*
* Slab allocation and freeing
*/
@@ -1291,10 +1305,17 @@
struct page *page;
struct kmem_cache_order_objects oo = s->oo;
gfp_t alloc_gfp;
+ bool enableirqs;
+ void *start, *last, *p;
+ int idx, order;
flags &= gfp_allowed_mask;
- if (flags & __GFP_WAIT)
+ enableirqs = (flags & __GFP_WAIT) != 0;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ enableirqs |= system_state == SYSTEM_RUNNING;
+#endif
+ if (enableirqs)
local_irq_enable();
flags |= s->allocflags;
@@ -1313,13 +1334,13 @@
* Try a lower order alloc if possible
*/
page = alloc_slab_page(flags, node, oo);
-
- if (page)
- stat(s, ORDER_FALLBACK);
+ if (unlikely(!page))
+ goto out;
+ stat(s, ORDER_FALLBACK);
}
- if (kmemcheck_enabled && page
- && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
+ if (kmemcheck_enabled &&
+ !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
int pages = 1 << oo_order(oo);
kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
@@ -1334,45 +1355,9 @@
kmemcheck_mark_unallocated_pages(page, pages);
}
- if (flags & __GFP_WAIT)
- local_irq_disable();
- if (!page)
- return NULL;
-
page->objects = oo_objects(oo);
- mod_zone_page_state(page_zone(page),
- (s->flags & SLAB_RECLAIM_ACCOUNT) ?
- NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
- 1 << oo_order(oo));
-
- return page;
-}
-
-static void setup_object(struct kmem_cache *s, struct page *page,
- void *object)
-{
- setup_object_debug(s, page, object);
- if (unlikely(s->ctor))
- s->ctor(object);
-}
-
-static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
-{
- struct page *page;
- void *start;
- void *last;
- void *p;
- int order;
-
- BUG_ON(flags & GFP_SLAB_BUG_MASK);
-
- page = allocate_slab(s,
- flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
- if (!page)
- goto out;
order = compound_order(page);
- inc_slabs_node(s, page_to_nid(page), page->objects);
memcg_bind_pages(s, order);
page->slab_cache = s;
__SetPageSlab(page);
@@ -1396,10 +1381,34 @@
page->freelist = start;
page->inuse = page->objects;
page->frozen = 1;
+
out:
+ if (enableirqs)
+ local_irq_disable();
+ if (!page)
+ return NULL;
+
+ mod_zone_page_state(page_zone(page),
+ (s->flags & SLAB_RECLAIM_ACCOUNT) ?
+ NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
+ 1 << oo_order(oo));
+
+ inc_slabs_node(s, page_to_nid(page), page->objects);
+
return page;
}
+static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
+{
+ if (unlikely(flags & GFP_SLAB_BUG_MASK)) {
+ pr_emerg("gfp: %u\n", flags & GFP_SLAB_BUG_MASK);
+ BUG();
+ }
+
+ return allocate_slab(s,
+ flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
+}
+
static void __free_slab(struct kmem_cache *s, struct page *page)
{
int order = compound_order(page);
@@ -1431,6 +1440,16 @@
__free_memcg_kmem_pages(page, order);
}
+static void free_delayed(struct list_head *h)
+{
+ while(!list_empty(h)) {
+ struct page *page = list_first_entry(h, struct page, lru);
+
+ list_del(&page->lru);
+ __free_slab(page->slab_cache, page);
+ }
+}
+
#define need_reserve_slab_rcu \
(sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
@@ -1465,6 +1484,12 @@
}
call_rcu(head, rcu_free_slab);
+ } else if (irqs_disabled()) {
+ struct slub_free_list *f = &__get_cpu_var(slub_free_list);
+
+ raw_spin_lock(&f->lock);
+ list_add(&page->lru, &f->list);
+ raw_spin_unlock(&f->lock);
} else
__free_slab(s, page);
}
@@ -1569,7 +1594,7 @@
if (!n || !n->nr_partial)
return NULL;
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
list_for_each_entry_safe(page, page2, &n->partial, lru) {
void *t;
@@ -1594,7 +1619,7 @@
break;
}
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
return object;
}
@@ -1835,7 +1860,7 @@
* that acquire_slab() will see a slab page that
* is frozen
*/
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
}
} else {
m = M_FULL;
@@ -1846,7 +1871,7 @@
* slabs from diagnostic functions will not see
* any frozen slabs.
*/
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
}
}
@@ -1881,7 +1906,7 @@
goto redo;
if (lock)
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
if (m == M_FREE) {
stat(s, DEACTIVATE_EMPTY);
@@ -1913,10 +1938,10 @@
n2 = get_node(s, page_to_nid(page));
if (n != n2) {
if (n)
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
n = n2;
- spin_lock(&n->list_lock);
+ raw_spin_lock(&n->list_lock);
}
do {
@@ -1945,7 +1970,7 @@
}
if (n)
- spin_unlock(&n->list_lock);
+ raw_spin_unlock(&n->list_lock);
while (discard_page) {
page = discard_page;
@@ -1983,14 +2008,21 @@
pobjects = oldpage->pobjects;
pages = oldpage->pages;
if (drain && pobjects > s->cpu_partial) {
+ struct slub_free_list *f;
unsigned long flags;
+ LIST_HEAD(tofree);
/*
* partial array is full. Move the existing
* set to the per node partial list.
*/
local_irq_save(flags);
unfreeze_partials(s, this_cpu_ptr(s->cpu_slab));
+ f = &__get_cpu_var(slub_free_list);
+ raw_spin_lock(&f->lock);
+ list_splice_init(&f->list, &tofree);
+ raw_spin_unlock(&f->lock);
local_irq_restore(flags);
+ free_delayed(&tofree);
oldpage = NULL;
pobjects = 0;
pages = 0;
@@ -2054,7 +2086,22 @@
static void flush_all(struct kmem_cache *s)
{
+ LIST_HEAD(tofree);
+ int cpu;
+
on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1, GFP_ATOMIC);
+ for_each_online_cpu(cpu) {
+ struct slub_free_list *f;
+
+ if (!has_cpu_slab(cpu, s))
+ continue;
+
+ f = &per_cpu(slub_free_list, cpu);
+ raw_spin_lock_irq(&f->lock);
+ list_splice_init(&f->list, &tofree);
+ raw_spin_unlock_irq(&f->lock);
+ free_delayed(&tofree);
+ }
}
/*
@@ -2082,10 +2129,10 @@
unsigned long x = 0;
struct page *page;
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry(page, &n->partial, lru)
x += get_count(page);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
return x;
}
@@ -2228,9 +2275,11 @@
static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
unsigned long addr, struct kmem_cache_cpu *c)
{
+ struct slub_free_list *f;
void *freelist;
struct page *page;
unsigned long flags;
+ LIST_HEAD(tofree);
local_irq_save(flags);
#ifdef CONFIG_PREEMPT
@@ -2293,7 +2342,13 @@
VM_BUG_ON(!c->page->frozen);
c->freelist = get_freepointer(s, freelist);
c->tid = next_tid(c->tid);
+out:
+ f = &__get_cpu_var(slub_free_list);
+ raw_spin_lock(&f->lock);
+ list_splice_init(&f->list, &tofree);
+ raw_spin_unlock(&f->lock);
local_irq_restore(flags);
+ free_delayed(&tofree);
return freelist;
new_slab:
@@ -2311,9 +2366,7 @@
if (unlikely(!freelist)) {
if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
slab_out_of_memory(s, gfpflags, node);
-
- local_irq_restore(flags);
- return NULL;
+ goto out;
}
page = c->page;
@@ -2328,8 +2381,7 @@
deactivate_slab(s, page, get_freepointer(s, freelist));
c->page = NULL;
c->freelist = NULL;
- local_irq_restore(flags);
- return freelist;
+ goto out;
}
/*
@@ -2501,7 +2553,7 @@
do {
if (unlikely(n)) {
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
n = NULL;
}
prior = page->freelist;
@@ -2533,7 +2585,7 @@
* Otherwise the list_lock will synchronize with
* other processors updating the list of slabs.
*/
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
}
}
@@ -2575,7 +2627,7 @@
add_partial(n, page, DEACTIVATE_TO_TAIL);
stat(s, FREE_ADD_PARTIAL);
}
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
return;
slab_empty:
@@ -2589,7 +2641,7 @@
/* Slab must be on the full list */
remove_full(s, page);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
stat(s, FREE_SLAB);
discard_slab(s, page);
}
@@ -2791,7 +2843,7 @@
init_kmem_cache_node(struct kmem_cache_node *n)
{
n->nr_partial = 0;
- spin_lock_init(&n->list_lock);
+ raw_spin_lock_init(&n->list_lock);
INIT_LIST_HEAD(&n->partial);
#ifdef CONFIG_SLUB_DEBUG
atomic_long_set(&n->nr_slabs, 0);
@@ -3377,7 +3429,7 @@
for (i = 0; i < objects; i++)
INIT_LIST_HEAD(slabs_by_inuse + i);
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
/*
* Build lists indexed by the items in use in each slab.
@@ -3398,7 +3450,7 @@
for (i = objects - 1; i > 0; i--)
list_splice(slabs_by_inuse + i, n->partial.prev);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
/* Release empty slabs */
list_for_each_entry_safe(page, t, slabs_by_inuse, lru)
@@ -3574,6 +3626,12 @@
{
static __initdata struct kmem_cache boot_kmem_cache,
boot_kmem_cache_node;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ raw_spin_lock_init(&per_cpu(slub_free_list, cpu).lock);
+ INIT_LIST_HEAD(&per_cpu(slub_free_list, cpu).list);
+ }
if (debug_guardpage_minorder())
slub_max_order = 0;
@@ -3878,7 +3936,7 @@
struct page *page;
unsigned long flags;
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry(page, &n->partial, lru) {
validate_slab_slab(s, page, map);
@@ -3901,7 +3959,7 @@
atomic_long_read(&n->nr_slabs));
out:
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
return count;
}
@@ -4091,12 +4149,12 @@
if (!atomic_long_read(&n->nr_slabs))
continue;
- spin_lock_irqsave(&n->list_lock, flags);
+ raw_spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry(page, &n->partial, lru)
process_slab(&t, s, page, alloc, map);
list_for_each_entry(page, &n->full, lru)
process_slab(&t, s, page, alloc, map);
- spin_unlock_irqrestore(&n->list_lock, flags);
+ raw_spin_unlock_irqrestore(&n->list_lock, flags);
}
for (i = 0; i < t.count; i++) {
diff --git a/mm/swap.c b/mm/swap.c
index a8e9439..7f23326 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -32,6 +32,7 @@
#include <linux/gfp.h>
#include <linux/uio.h>
#include <linux/hugetlb.h>
+#include <linux/locallock.h>
#include "internal.h"
@@ -45,6 +46,9 @@
static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs);
static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs);
+static DEFINE_LOCAL_IRQ_LOCK(rotate_lock);
+static DEFINE_LOCAL_IRQ_LOCK(swapvec_lock);
+
/*
* This path almost never happens for VM activity - pages are normally
* freed via pagevecs. But it gets used by networking.
@@ -408,11 +412,11 @@
unsigned long flags;
page_cache_get(page);
- local_irq_save(flags);
+ local_lock_irqsave(rotate_lock, flags);
pvec = &__get_cpu_var(lru_rotate_pvecs);
if (!pagevec_add(pvec, page) || PageCompound(page))
pagevec_move_tail(pvec);
- local_irq_restore(flags);
+ local_unlock_irqrestore(rotate_lock, flags);
}
}
@@ -463,12 +467,13 @@
void activate_page(struct page *page)
{
if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
- struct pagevec *pvec = &get_cpu_var(activate_page_pvecs);
+ struct pagevec *pvec = &get_locked_var(swapvec_lock,
+ activate_page_pvecs);
page_cache_get(page);
if (!pagevec_add(pvec, page) || PageCompound(page))
pagevec_lru_move_fn(pvec, __activate_page, NULL);
- put_cpu_var(activate_page_pvecs);
+ put_locked_var(swapvec_lock, activate_page_pvecs);
}
}
@@ -494,7 +499,7 @@
static void __lru_cache_activate_page(struct page *page)
{
- struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
+ struct pagevec *pvec = &get_locked_var(swapvec_lock, lru_add_pvec);
int i;
/*
@@ -516,7 +521,7 @@
}
}
- put_cpu_var(lru_add_pvec);
+ put_locked_var(swapvec_lock, lru_add_pvec);
}
/*
@@ -561,12 +566,12 @@
static void __lru_cache_add(struct page *page)
{
- struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
+ struct pagevec *pvec = &get_locked_var(swapvec_lock, lru_add_pvec);
page_cache_get(page);
if (!pagevec_add(pvec, page) || PageCompound(page))
__pagevec_lru_add(pvec);
- put_cpu_var(lru_add_pvec);
+ put_locked_var(swapvec_lock, lru_add_pvec);
}
/**
@@ -712,9 +717,15 @@
unsigned long flags;
/* No harm done if a racing interrupt already did this */
- local_irq_save(flags);
+#ifdef CONFIG_PREEMPT_RT_BASE
+ local_lock_irqsave_on(rotate_lock, flags, cpu);
pagevec_move_tail(pvec);
- local_irq_restore(flags);
+ local_unlock_irqrestore_on(rotate_lock, flags, cpu);
+#else
+ local_lock_irqsave(rotate_lock, flags);
+ pagevec_move_tail(pvec);
+ local_unlock_irqrestore(rotate_lock, flags);
+#endif
}
pvec = &per_cpu(lru_deactivate_pvecs, cpu);
@@ -742,26 +753,47 @@
return;
if (likely(get_page_unless_zero(page))) {
- struct pagevec *pvec = &get_cpu_var(lru_deactivate_pvecs);
+ struct pagevec *pvec = &get_locked_var(swapvec_lock,
+ lru_deactivate_pvecs);
if (!pagevec_add(pvec, page) || PageCompound(page))
pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL);
- put_cpu_var(lru_deactivate_pvecs);
+ put_locked_var(swapvec_lock, lru_deactivate_pvecs);
}
}
void lru_add_drain(void)
{
- lru_add_drain_cpu(get_cpu());
- put_cpu();
+ lru_add_drain_cpu(local_lock_cpu(swapvec_lock));
+ local_unlock_cpu(swapvec_lock);
}
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+static inline void remote_lru_add_drain(int cpu, struct cpumask *has_work)
+{
+ local_lock_on(swapvec_lock, cpu);
+ lru_add_drain_cpu(cpu);
+ local_unlock_on(swapvec_lock, cpu);
+}
+
+#else
+
static void lru_add_drain_per_cpu(struct work_struct *dummy)
{
lru_add_drain();
}
static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work);
+static inline void remote_lru_add_drain(int cpu, struct cpumask *has_work)
+{
+ struct work_struct *work = &per_cpu(lru_add_drain_work, cpu);
+
+ INIT_WORK(work, lru_add_drain_per_cpu);
+ schedule_work_on(cpu, work);
+ cpumask_set_cpu(cpu, has_work);
+}
+#endif
void lru_add_drain_all(void)
{
@@ -774,20 +806,17 @@
cpumask_clear(&has_work);
for_each_online_cpu(cpu) {
- struct work_struct *work = &per_cpu(lru_add_drain_work, cpu);
-
if (pagevec_count(&per_cpu(lru_add_pvec, cpu)) ||
pagevec_count(&per_cpu(lru_rotate_pvecs, cpu)) ||
pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) ||
- need_activate_page_drain(cpu)) {
- INIT_WORK(work, lru_add_drain_per_cpu);
- schedule_work_on(cpu, work);
- cpumask_set_cpu(cpu, &has_work);
- }
+ need_activate_page_drain(cpu))
+ remote_lru_add_drain(cpu, &has_work);
}
+#ifndef CONFIG_PREEMPT_RT_BASE
for_each_cpu(cpu, &has_work)
flush_work(&per_cpu(lru_add_drain_work, cpu));
+#endif
put_online_cpus();
mutex_unlock(&lock);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 060dc36..83e33b8 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -796,7 +796,7 @@
struct vmap_block *vb;
struct vmap_area *va;
unsigned long vb_idx;
- int node, err;
+ int node, err, cpu;
node = numa_node_id();
@@ -834,11 +834,12 @@
BUG_ON(err);
radix_tree_preload_end();
- vbq = &get_cpu_var(vmap_block_queue);
+ cpu = get_cpu_light();
+ vbq = &__get_cpu_var(vmap_block_queue);
spin_lock(&vbq->lock);
list_add_rcu(&vb->free_list, &vbq->free);
spin_unlock(&vbq->lock);
- put_cpu_var(vmap_block_queue);
+ put_cpu_light();
return vb;
}
@@ -906,6 +907,7 @@
struct vmap_block *vb;
unsigned long addr = 0;
unsigned int order;
+ int cpu = 0;
BUG_ON(size & ~PAGE_MASK);
BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
@@ -921,7 +923,8 @@
again:
rcu_read_lock();
- vbq = &get_cpu_var(vmap_block_queue);
+ cpu = get_cpu_light();
+ vbq = &__get_cpu_var(vmap_block_queue);
list_for_each_entry_rcu(vb, &vbq->free, free_list) {
int i;
@@ -945,7 +948,7 @@
spin_unlock(&vb->lock);
}
- put_cpu_var(vmap_block_queue);
+ put_cpu_light();
rcu_read_unlock();
if (!addr) {
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 1dbd89d..8fcc812 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -217,6 +217,7 @@
long x;
long t;
+ preempt_disable_rt();
x = delta + __this_cpu_read(*p);
t = __this_cpu_read(pcp->stat_threshold);
@@ -226,6 +227,7 @@
x = 0;
}
__this_cpu_write(*p, x);
+ preempt_enable_rt();
}
EXPORT_SYMBOL(__mod_zone_page_state);
@@ -258,6 +260,7 @@
s8 __percpu *p = pcp->vm_stat_diff + item;
s8 v, t;
+ preempt_disable_rt();
v = __this_cpu_inc_return(*p);
t = __this_cpu_read(pcp->stat_threshold);
if (unlikely(v > t)) {
@@ -266,6 +269,7 @@
zone_page_state_add(v + overstep, zone, item);
__this_cpu_write(*p, -overstep);
}
+ preempt_enable_rt();
}
void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
@@ -280,6 +284,7 @@
s8 __percpu *p = pcp->vm_stat_diff + item;
s8 v, t;
+ preempt_disable_rt();
v = __this_cpu_dec_return(*p);
t = __this_cpu_read(pcp->stat_threshold);
if (unlikely(v < - t)) {
@@ -288,6 +293,7 @@
zone_page_state_add(v - overstep, zone, item);
__this_cpu_write(*p, overstep);
}
+ preempt_enable_rt();
}
void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
diff --git a/net/core/dev.c b/net/core/dev.c
index a8574b4..8cab710 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -175,6 +175,7 @@
static DEFINE_HASHTABLE(napi_hash, 8);
static seqcount_t devnet_rename_seq;
+static DEFINE_MUTEX(devnet_rename_mutex);
static inline void dev_base_seq_inc(struct net *net)
{
@@ -196,14 +197,14 @@
static inline void rps_lock(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
- spin_lock(&sd->input_pkt_queue.lock);
+ raw_spin_lock(&sd->input_pkt_queue.raw_lock);
#endif
}
static inline void rps_unlock(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
- spin_unlock(&sd->input_pkt_queue.lock);
+ raw_spin_unlock(&sd->input_pkt_queue.raw_lock);
#endif
}
@@ -826,7 +827,8 @@
strcpy(name, dev->name);
rcu_read_unlock();
if (read_seqcount_retry(&devnet_rename_seq, seq)) {
- cond_resched();
+ mutex_lock(&devnet_rename_mutex);
+ mutex_unlock(&devnet_rename_mutex);
goto retry;
}
@@ -1092,30 +1094,28 @@
if (dev->flags & IFF_UP)
return -EBUSY;
- write_seqcount_begin(&devnet_rename_seq);
+ mutex_lock(&devnet_rename_mutex);
+ __write_seqcount_begin(&devnet_rename_seq);
- if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
- write_seqcount_end(&devnet_rename_seq);
- return 0;
- }
+ if (strncmp(newname, dev->name, IFNAMSIZ) == 0)
+ goto outunlock;
memcpy(oldname, dev->name, IFNAMSIZ);
err = dev_get_valid_name(net, dev, newname);
- if (err < 0) {
- write_seqcount_end(&devnet_rename_seq);
- return err;
- }
+ if (err < 0)
+ goto outunlock;
rollback:
ret = device_rename(&dev->dev, dev->name);
if (ret) {
memcpy(dev->name, oldname, IFNAMSIZ);
- write_seqcount_end(&devnet_rename_seq);
- return ret;
+ err = ret;
+ goto outunlock;
}
- write_seqcount_end(&devnet_rename_seq);
+ __write_seqcount_end(&devnet_rename_seq);
+ mutex_unlock(&devnet_rename_mutex);
write_lock_bh(&dev_base_lock);
hlist_del_rcu(&dev->name_hlist);
@@ -1134,7 +1134,8 @@
/* err >= 0 after dev_alloc_name() or stores the first errno */
if (err >= 0) {
err = ret;
- write_seqcount_begin(&devnet_rename_seq);
+ mutex_lock(&devnet_rename_mutex);
+ __write_seqcount_begin(&devnet_rename_seq);
memcpy(dev->name, oldname, IFNAMSIZ);
goto rollback;
} else {
@@ -1144,6 +1145,11 @@
}
return err;
+
+outunlock:
+ __write_seqcount_end(&devnet_rename_seq);
+ mutex_unlock(&devnet_rename_mutex);
+ return err;
}
/**
@@ -2159,6 +2165,7 @@
sd->output_queue_tailp = &q->next_sched;
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
void __netif_schedule(struct Qdisc *q)
@@ -2180,6 +2187,7 @@
sd->completion_queue = skb;
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
}
EXPORT_SYMBOL(dev_kfree_skb_irq);
@@ -2727,7 +2735,11 @@
* This permits __QDISC_STATE_RUNNING owner to get the lock more often
* and dequeue packets faster.
*/
+#ifdef CONFIG_PREEMPT_RT_FULL
+ contended = true;
+#else
contended = qdisc_is_running(q);
+#endif
if (unlikely(contended))
spin_lock(&q->busylock);
@@ -3243,6 +3255,7 @@
rps_unlock(sd);
local_irq_restore(flags);
+ preempt_check_resched_rt();
atomic_long_inc(&skb->dev->rx_dropped);
kfree_skb(skb);
@@ -3280,7 +3293,7 @@
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu;
- preempt_disable();
+ migrate_disable();
rcu_read_lock();
cpu = get_rps_cpu(skb->dev, skb, &rflow);
@@ -3290,13 +3303,13 @@
ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
rcu_read_unlock();
- preempt_enable();
+ migrate_enable();
} else
#endif
{
unsigned int qtail;
- ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
- put_cpu();
+ ret = enqueue_to_backlog(skb, get_cpu_light(), &qtail);
+ put_cpu_light();
}
return ret;
}
@@ -3306,16 +3319,44 @@
{
int err;
- preempt_disable();
+ local_bh_disable();
err = netif_rx(skb);
- if (local_softirq_pending())
- do_softirq();
- preempt_enable();
+ local_bh_enable();
return err;
}
EXPORT_SYMBOL(netif_rx_ni);
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * RT runs ksoftirqd as a real time thread and the root_lock is a
+ * "sleeping spinlock". If the trylock fails then we can go into an
+ * infinite loop when ksoftirqd preempted the task which actually
+ * holds the lock, because we requeue q and raise NET_TX softirq
+ * causing ksoftirqd to loop forever.
+ *
+ * It's safe to use spin_lock on RT here as softirqs run in thread
+ * context and cannot deadlock against the thread which is holding
+ * root_lock.
+ *
+ * On !RT the trylock might fail, but there we bail out from the
+ * softirq loop after 10 attempts which we can't do on RT. And the
+ * task holding root_lock cannot be preempted, so the only downside of
+ * that trylock is that we need 10 loops to decide that we should have
+ * given up in the first one :)
+ */
+static inline int take_root_lock(spinlock_t *lock)
+{
+ spin_lock(lock);
+ return 1;
+}
+#else
+static inline int take_root_lock(spinlock_t *lock)
+{
+ return spin_trylock(lock);
+}
+#endif
+
static void net_tx_action(struct softirq_action *h)
{
struct softnet_data *sd = &__get_cpu_var(softnet_data);
@@ -3354,7 +3395,7 @@
head = head->next_sched;
root_lock = qdisc_lock(q);
- if (spin_trylock(root_lock)) {
+ if (take_root_lock(root_lock)) {
smp_mb__before_clear_bit();
clear_bit(__QDISC_STATE_SCHED,
&q->state);
@@ -3758,7 +3799,7 @@
skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
if (skb->dev == dev) {
__skb_unlink(skb, &sd->input_pkt_queue);
- kfree_skb(skb);
+ __skb_queue_tail(&sd->tofree_queue, skb);
input_queue_head_incr(sd);
}
}
@@ -3767,10 +3808,13 @@
skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
if (skb->dev == dev) {
__skb_unlink(skb, &sd->process_queue);
- kfree_skb(skb);
+ __skb_queue_tail(&sd->tofree_queue, skb);
input_queue_head_incr(sd);
}
}
+
+ if (!skb_queue_empty(&sd->tofree_queue))
+ raise_softirq_irqoff(NET_RX_SOFTIRQ);
}
static int napi_gro_complete(struct sk_buff *skb)
@@ -4130,6 +4174,7 @@
} else
#endif
local_irq_enable();
+ preempt_check_resched_rt();
}
static int process_backlog(struct napi_struct *napi, int quota)
@@ -4204,6 +4249,7 @@
local_irq_save(flags);
____napi_schedule(&__get_cpu_var(softnet_data), n);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
EXPORT_SYMBOL(__napi_schedule);
@@ -4333,10 +4379,17 @@
struct softnet_data *sd = &__get_cpu_var(softnet_data);
unsigned long time_limit = jiffies + 2;
int budget = netdev_budget;
+ struct sk_buff *skb;
void *have;
local_irq_disable();
+ while ((skb = __skb_dequeue(&sd->tofree_queue))) {
+ local_irq_enable();
+ kfree_skb(skb);
+ local_irq_disable();
+ }
+
while (!list_empty(&sd->poll_list)) {
struct napi_struct *n;
int work, weight;
@@ -4419,7 +4472,7 @@
softnet_break:
sd->time_squeeze++;
- __raise_softirq_irqoff(NET_RX_SOFTIRQ);
+ __raise_softirq_irqoff_ksoft(NET_RX_SOFTIRQ);
goto out;
}
@@ -6232,7 +6285,7 @@
void synchronize_net(void)
{
might_sleep();
- if (rtnl_is_locked())
+ if (rtnl_is_locked() && !IS_ENABLED(CONFIG_PREEMPT_RT_FULL))
synchronize_rcu_expedited();
else
synchronize_rcu();
@@ -6475,16 +6528,20 @@
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
/* Process offline CPU's input_pkt_queue */
while ((skb = __skb_dequeue(&oldsd->process_queue))) {
netif_rx(skb);
input_queue_head_incr(oldsd);
}
- while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
+ while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
netif_rx(skb);
input_queue_head_incr(oldsd);
}
+ while ((skb = __skb_dequeue(&oldsd->tofree_queue))) {
+ kfree_skb(skb);
+ }
return NOTIFY_OK;
}
@@ -6795,8 +6852,9 @@
struct softnet_data *sd = &per_cpu(softnet_data, i);
memset(sd, 0, sizeof(*sd));
- skb_queue_head_init(&sd->input_pkt_queue);
- skb_queue_head_init(&sd->process_queue);
+ skb_queue_head_init_raw(&sd->input_pkt_queue);
+ skb_queue_head_init_raw(&sd->process_queue);
+ skb_queue_head_init_raw(&sd->tofree_queue);
sd->completion_queue = NULL;
INIT_LIST_HEAD(&sd->poll_list);
sd->output_queue = NULL;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 7df6f53..4d49548 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -63,6 +63,7 @@
#include <linux/errqueue.h>
#include <linux/prefetch.h>
#include <linux/if_vlan.h>
+#include <linux/locallock.h>
#include <net/protocol.h>
#include <net/dst.h>
@@ -354,6 +355,7 @@
unsigned int pagecnt_bias;
};
static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache);
+static DEFINE_LOCAL_IRQ_LOCK(netdev_alloc_lock);
static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
{
@@ -362,7 +364,7 @@
int order;
unsigned long flags;
- local_irq_save(flags);
+ local_lock_irqsave(netdev_alloc_lock, flags);
nc = &__get_cpu_var(netdev_alloc_cache);
if (unlikely(!nc->frag.page)) {
refill:
@@ -399,7 +401,7 @@
nc->frag.offset += fragsz;
nc->pagecnt_bias--;
end:
- local_irq_restore(flags);
+ local_unlock_irqrestore(netdev_alloc_lock, flags);
return data;
}
diff --git a/net/core/sock.c b/net/core/sock.c
index 046a72a..748b661 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2401,12 +2401,11 @@
if (sk->sk_lock.owned)
__lock_sock(sk);
sk->sk_lock.owned = 1;
- spin_unlock(&sk->sk_lock.slock);
+ spin_unlock_bh(&sk->sk_lock.slock);
/*
* The sk_lock has mutex_lock() semantics here:
*/
mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
- local_bh_enable();
}
EXPORT_SYMBOL(lock_sock_nested);
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index ff670ca..a599898 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -69,6 +69,7 @@
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/fcntl.h>
+#include <linux/sysrq.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/inet.h>
@@ -77,6 +78,7 @@
#include <linux/string.h>
#include <linux/netfilter_ipv4.h>
#include <linux/slab.h>
+#include <linux/locallock.h>
#include <net/snmp.h>
#include <net/ip.h>
#include <net/route.h>
@@ -203,6 +205,8 @@
*
* On SMP we have one ICMP socket per-cpu.
*/
+static DEFINE_LOCAL_IRQ_LOCK(icmp_sk_lock);
+
static struct sock *icmp_sk(struct net *net)
{
return net->ipv4.icmp_sk[smp_processor_id()];
@@ -214,12 +218,14 @@
local_bh_disable();
+ local_lock(icmp_sk_lock);
sk = icmp_sk(net);
if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
/* This can happen if the output path signals a
* dst_link_failure() for an outgoing ICMP packet.
*/
+ local_unlock(icmp_sk_lock);
local_bh_enable();
return NULL;
}
@@ -229,6 +235,7 @@
static inline void icmp_xmit_unlock(struct sock *sk)
{
spin_unlock_bh(&sk->sk_lock.slock);
+ local_unlock(icmp_sk_lock);
}
/*
@@ -300,6 +307,7 @@
struct sock *sk;
struct sk_buff *skb;
+ local_lock(icmp_sk_lock);
sk = icmp_sk(dev_net((*rt)->dst.dev));
if (ip_append_data(sk, fl4, icmp_glue_bits, icmp_param,
icmp_param->data_len+icmp_param->head_len,
@@ -322,6 +330,7 @@
skb->ip_summed = CHECKSUM_NONE;
ip_push_pending_frames(sk, fl4);
}
+ local_unlock(icmp_sk_lock);
}
/*
@@ -774,6 +783,30 @@
}
/*
+ * 32bit and 64bit have different timestamp length, so we check for
+ * the cookie at offset 20 and verify it is repeated at offset 50
+ */
+#define CO_POS0 20
+#define CO_POS1 50
+#define CO_SIZE sizeof(int)
+#define ICMP_SYSRQ_SIZE 57
+
+/*
+ * We got a ICMP_SYSRQ_SIZE sized ping request. Check for the cookie
+ * pattern and if it matches send the next byte as a trigger to sysrq.
+ */
+static void icmp_check_sysrq(struct net *net, struct sk_buff *skb)
+{
+ int cookie = htonl(net->ipv4.sysctl_icmp_echo_sysrq);
+ char *p = skb->data;
+
+ if (!memcmp(&cookie, p + CO_POS0, CO_SIZE) &&
+ !memcmp(&cookie, p + CO_POS1, CO_SIZE) &&
+ p[CO_POS0 + CO_SIZE] == p[CO_POS1 + CO_SIZE])
+ handle_sysrq(p[CO_POS0 + CO_SIZE]);
+}
+
+/*
* Handle ICMP_ECHO ("ping") requests.
*
* RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo
@@ -800,6 +833,11 @@
icmp_param.data_len = skb->len;
icmp_param.head_len = sizeof(struct icmphdr);
icmp_reply(&icmp_param, skb);
+
+ if (skb->len == ICMP_SYSRQ_SIZE &&
+ net->ipv4.sysctl_icmp_echo_sysrq) {
+ icmp_check_sysrq(net, skb);
+ }
}
}
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 540279f..99461ed 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -812,6 +812,13 @@
.proc_handler = proc_dointvec
},
{
+ .procname = "icmp_echo_sysrq",
+ .data = &init_net.ipv4.sysctl_icmp_echo_sysrq,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
+ {
.procname = "icmp_ignore_bogus_error_responses",
.data = &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
.maxlen = sizeof(int),
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 129af2a..cd0a2ad 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -62,6 +62,7 @@
#include <linux/init.h>
#include <linux/times.h>
#include <linux/slab.h>
+#include <linux/locallock.h>
#include <net/net_namespace.h>
#include <net/icmp.h>
@@ -576,6 +577,7 @@
}
EXPORT_SYMBOL(tcp_v4_send_check);
+static DEFINE_LOCAL_IRQ_LOCK(tcp_sk_lock);
/*
* This routine will send an RST to the other tcp.
*
@@ -694,9 +696,12 @@
net = dev_net(skb_dst(skb)->dev);
arg.tos = ip_hdr(skb)->tos;
+
+ local_lock(tcp_sk_lock);
ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
skb, ip_hdr(skb)->saddr,
ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len);
+ local_unlock(tcp_sk_lock);
TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
@@ -778,9 +783,11 @@
if (oif)
arg.bound_dev_if = oif;
arg.tos = tos;
+ local_lock(tcp_sk_lock);
ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
skb, ip_hdr(skb)->saddr,
ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len);
+ local_unlock(tcp_sk_lock);
TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
}
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 4003bd6..a211101 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -3309,7 +3309,7 @@
struct ieee80211_supported_band *sband;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
- WARN_ON_ONCE(softirq_count() == 0);
+ WARN_ON_ONCE_NONRT(softirq_count() == 0);
if (WARN_ON(status->band >= IEEE80211_NUM_BANDS))
goto drop;
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index 593b16e..6bd22aa 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -21,11 +21,17 @@
#include <linux/proc_fs.h>
#include <linux/mutex.h>
#include <linux/slab.h>
+#include <linux/locallock.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include "nf_internals.h"
+#ifdef CONFIG_PREEMPT_RT_BASE
+DEFINE_LOCAL_IRQ_LOCK(xt_write_lock);
+EXPORT_PER_CPU_SYMBOL(xt_write_lock);
+#endif
+
static DEFINE_MUTEX(afinfo_mutex);
const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO] __read_mostly;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 2455f1b..9c08229 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -63,6 +63,7 @@
#include <linux/if_packet.h>
#include <linux/wireless.h>
#include <linux/kernel.h>
+#include <linux/delay.h>
#include <linux/kmod.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
@@ -632,7 +633,7 @@
if (BLOCK_NUM_PKTS(pbd)) {
while (atomic_read(&pkc->blk_fill_in_prog)) {
/* Waiting for skb_copy_bits to finish... */
- cpu_relax();
+ cpu_chill();
}
}
@@ -883,7 +884,7 @@
if (!(status & TP_STATUS_BLK_TMO)) {
while (atomic_read(&pkc->blk_fill_in_prog)) {
/* Waiting for skb_copy_bits to finish... */
- cpu_relax();
+ cpu_chill();
}
}
prb_close_block(pkc, pbd, po, status);
diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index a985158..0f63c71 100644
--- a/net/rds/ib_rdma.c
+++ b/net/rds/ib_rdma.c
@@ -34,6 +34,7 @@
#include <linux/slab.h>
#include <linux/rculist.h>
#include <linux/llist.h>
+#include <linux/delay.h>
#include "rds.h"
#include "ib.h"
@@ -286,7 +287,7 @@
for_each_online_cpu(cpu) {
flag = &per_cpu(clean_list_grace, cpu);
while (test_bit(CLEAN_LIST_BUSY_BIT, flag))
- cpu_relax();
+ cpu_chill();
}
}
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index a74e278..1dcebc9 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -850,7 +850,7 @@
/* Wait for outstanding qdisc_run calls. */
list_for_each_entry(dev, head, unreg_list)
while (some_qdisc_is_busy(dev))
- yield();
+ msleep(1);
}
void dev_deactivate(struct net_device *dev)
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index b9aad47..ab50dbd 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -349,9 +349,9 @@
if (!svc_xprt_has_something_to_do(xprt))
return;
- cpu = get_cpu();
+ cpu = get_cpu_light();
pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
- put_cpu();
+ put_cpu_light();
spin_lock_bh(&pool->sp_lock);
diff --git a/scripts/mkcompile_h b/scripts/mkcompile_h
index f221ddf..5f44009 100755
--- a/scripts/mkcompile_h
+++ b/scripts/mkcompile_h
@@ -4,7 +4,8 @@
ARCH=$2
SMP=$3
PREEMPT=$4
-CC=$5
+RT=$5
+CC=$6
vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
@@ -57,6 +58,7 @@
CONFIG_FLAGS=""
if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
+if [ -n "$RT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS RT"; fi
UTS_VERSION="$UTS_VERSION $CONFIG_FLAGS $TIMESTAMP"
# Truncate to maximum length
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index 0ae1bc4..f5295a5 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -85,8 +85,8 @@
trace_kvm_async_pf_completed(addr, page, gva);
- if (waitqueue_active(&vcpu->wq))
- wake_up_interruptible(&vcpu->wq);
+ if (swaitqueue_active(&vcpu->wq))
+ swait_wake_interruptible(&vcpu->wq);
mmdrop(mm);
kvm_put_kvm(vcpu->kvm);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 96fe24e..8473c9c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -213,7 +213,7 @@
vcpu->kvm = kvm;
vcpu->vcpu_id = id;
vcpu->pid = NULL;
- init_waitqueue_head(&vcpu->wq);
+ init_swait_head(&vcpu->wq);
kvm_async_pf_vcpu_init(vcpu);
page = alloc_page(GFP_KERNEL | __GFP_ZERO);
@@ -1667,10 +1667,10 @@
*/
void kvm_vcpu_block(struct kvm_vcpu *vcpu)
{
- DEFINE_WAIT(wait);
+ DEFINE_SWAITER(wait);
for (;;) {
- prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
+ swait_prepare(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
if (kvm_arch_vcpu_runnable(vcpu)) {
kvm_make_request(KVM_REQ_UNHALT, vcpu);
@@ -1684,7 +1684,7 @@
schedule();
}
- finish_wait(&vcpu->wq, &wait);
+ swait_finish(&vcpu->wq, &wait);
}
#ifndef CONFIG_S390
@@ -1695,11 +1695,11 @@
{
int me;
int cpu = vcpu->cpu;
- wait_queue_head_t *wqp;
+ struct swait_head *wqp;
wqp = kvm_arch_vcpu_wq(vcpu);
- if (waitqueue_active(wqp)) {
- wake_up_interruptible(wqp);
+ if (swaitqueue_active(wqp)) {
+ swait_wake_interruptible(wqp);
++vcpu->stat.halt_wakeup;
}
@@ -1811,7 +1811,7 @@
continue;
if (vcpu == me)
continue;
- if (waitqueue_active(&vcpu->wq))
+ if (swaitqueue_active(&vcpu->wq))
continue;
if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
continue;
