patches-3.10.10-rt7.tar.xz
md5sum:
f962e0301086b610da801f1816d38862 patches-3.10.10-rt7.tar.xz
Announce:
--------------
Dear RT folks!
I'm pleased to announce the v3.10.10-rt7 patch set.
Changes since v3.10.10-rt6
- hwlat compiles on 32bit (again). Reported by Fernando Lopez-Lezcano.
- bcache is disabled due to usage of anon semaphores. Anyone interrested
in using it?
- "genirq affinity callback" are fixed. Reported by Joe Korty. There are
two nics using this feature.
- Paul Gortmaker's swait rename patch has been included.
Known issues:
- SLAB support not working
- The cpsw network driver shows some issues.
- bcache is disabled.
- an ancient race (since we got sleeping spinlocks) where the
TASK_TRACED state is temporary replaced while waiting on a rw
lock and the task can't be traced.
The delta patch against v3.10.10-rt6 is appended below and can be found
here:
https://www.kernel.org/pub/linux/kernel/projects/rt/3.10/incr/patch-3.10.10-rt6-rt7.patch.xz
The RT patch against 3.10.10 can be found here:
https://www.kernel.org/pub/linux/kernel/projects/rt/3.10/patch-3.10.10-rt7.patch.xz
The split quilt queue is available at:
https://www.kernel.org/pub/linux/kernel/projects/rt/3.10/patches-3.10.10-rt7.tar.xz
Sebastian
[delta diff snipped]
--------------
http://marc.info/?l=linux-rt-users&m=137780177007595&w=2
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/patches/genirq-do-not-invoke-the-affinity-callback-via-a-wor.patch b/patches/genirq-do-not-invoke-the-affinity-callback-via-a-wor.patch
index 5dbd27d..ba6001b 100644
--- a/patches/genirq-do-not-invoke-the-affinity-callback-via-a-wor.patch
+++ b/patches/genirq-do-not-invoke-the-affinity-callback-via-a-wor.patch
@@ -11,15 +11,13 @@
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
- include/linux/interrupt.h | 1 +
- kernel/irq/manage.c | 79 +++++++++++++++++++++++++++++++++++++++++++++--
+ include/linux/interrupt.h | 1
+ kernel/irq/manage.c | 79 ++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 77 insertions(+), 3 deletions(-)
-diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
-index 11bdb1e..838d4bd 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
-@@ -263,6 +263,7 @@ struct irq_affinity_notify {
+@@ -261,6 +261,7 @@ struct irq_affinity_notify {
unsigned int irq;
struct kref kref;
struct work_struct work;
@@ -27,11 +25,9 @@
void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
void (*release)(struct kref *ref);
};
-diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
-index 0e34a98..5999a67 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
-@@ -164,6 +164,62 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
+@@ -164,6 +164,62 @@ int irq_do_set_affinity(struct irq_data
return ret;
}
@@ -65,7 +61,7 @@
+ if (!list_empty(&affinity_list)) {
+ notify = list_first_entry(&affinity_list,
+ struct irq_affinity_notify, list);
-+ list_del(¬ify->list);
++ list_del_init(¬ify->list);
+ }
+ raw_spin_unlock_irq(&affinity_list_lock);
+
@@ -94,7 +90,7 @@
int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
{
struct irq_chip *chip = irq_data_get_irq_chip(data);
-@@ -182,7 +238,17 @@ int __irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask)
+@@ -182,7 +238,17 @@ int __irq_set_affinity_locked(struct irq
if (desc->affinity_notify) {
kref_get(&desc->affinity_notify->kref);
@@ -112,7 +108,7 @@
}
irqd_set(data, IRQD_AFFINITY_SET);
-@@ -223,10 +289,8 @@ int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
+@@ -223,10 +289,8 @@ int irq_set_affinity_hint(unsigned int i
}
EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
@@ -124,7 +120,7 @@
struct irq_desc *desc = irq_to_desc(notify->irq);
cpumask_var_t cpumask;
unsigned long flags;
-@@ -248,6 +312,13 @@ static void irq_affinity_notify(struct work_struct *work)
+@@ -248,6 +312,13 @@ out:
kref_put(¬ify->kref, notify->release);
}
@@ -138,7 +134,7 @@
/**
* irq_set_affinity_notifier - control notification of IRQ affinity changes
* @irq: Interrupt for which to enable/disable notification
-@@ -277,6 +348,8 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
+@@ -277,6 +348,8 @@ irq_set_affinity_notifier(unsigned int i
notify->irq = irq;
kref_init(¬ify->kref);
INIT_WORK(¬ify->work, irq_affinity_notify);
@@ -147,6 +143,3 @@
}
raw_spin_lock_irqsave(&desc->lock, flags);
---
-1.8.4.rc3
-
diff --git a/patches/hwlat-detector-Update-hwlat_detector-to-add-outer-lo.patch b/patches/hwlat-detector-Update-hwlat_detector-to-add-outer-lo.patch
index 253b4dd..15fb8ed 100644
--- a/patches/hwlat-detector-Update-hwlat_detector-to-add-outer-lo.patch
+++ b/patches/hwlat-detector-Update-hwlat_detector-to-add-outer-lo.patch
@@ -43,11 +43,9 @@
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
- drivers/misc/hwlat_detector.c | 32 ++++++++++++++++++++++++++------
+ drivers/misc/hwlat_detector.c | 32 ++++++++++++++++++++++++++------
1 file changed, 26 insertions(+), 6 deletions(-)
-diff --git a/drivers/misc/hwlat_detector.c b/drivers/misc/hwlat_detector.c
-index b7b7c90..f93b8ef 100644
--- a/drivers/misc/hwlat_detector.c
+++ b/drivers/misc/hwlat_detector.c
@@ -143,6 +143,7 @@ static void detector_exit(void);
@@ -58,7 +56,7 @@
struct timespec timestamp; /* wall time */
unsigned long lost;
};
-@@ -219,11 +220,13 @@ static struct sample *buffer_get_sample(struct sample *sample)
+@@ -219,11 +220,13 @@ static struct sample *buffer_get_sample(
*/
static int get_sample(void *unused)
{
@@ -111,7 +109,7 @@
s.timestamp = CURRENT_TIME;
__buffer_add_sample(&s);
-@@ -738,10 +757,11 @@ static ssize_t debug_sample_fread(struct file *filp, char __user *ubuf,
+@@ -738,10 +757,11 @@ static ssize_t debug_sample_fread(struct
}
}
@@ -127,6 +125,3 @@
/* handling partial reads is more trouble than it's worth */
---
-1.8.4.rc3
-
diff --git a/patches/hwlat-detector-Use-thread-instead-of-stop-machine.patch b/patches/hwlat-detector-Use-thread-instead-of-stop-machine.patch
index f41beef..9f6e72b 100644
--- a/patches/hwlat-detector-Use-thread-instead-of-stop-machine.patch
+++ b/patches/hwlat-detector-Use-thread-instead-of-stop-machine.patch
@@ -14,11 +14,9 @@
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
- drivers/misc/hwlat_detector.c | 59 ++++++++++++++++++-------------------------
+ drivers/misc/hwlat_detector.c | 59 +++++++++++++++++-------------------------
1 file changed, 25 insertions(+), 34 deletions(-)
-diff --git a/drivers/misc/hwlat_detector.c b/drivers/misc/hwlat_detector.c
-index d80a857..0bfa40d 100644
--- a/drivers/misc/hwlat_detector.c
+++ b/drivers/misc/hwlat_detector.c
@@ -41,7 +41,6 @@
@@ -55,7 +53,7 @@
*/
static int __buffer_add_sample(struct sample *sample)
{
-@@ -229,18 +227,17 @@ static struct sample *buffer_get_sample(struct sample *sample)
+@@ -229,18 +227,17 @@ static struct sample *buffer_get_sample(
#endif
/**
* get_sample - sample the CPU TSC and look for likely hardware latencies
@@ -100,7 +98,7 @@
out:
return ret;
}
-@@ -305,32 +305,30 @@ static int get_sample(void *unused)
+@@ -305,32 +305,30 @@ out:
* @unused: A required part of the kthread API.
*
* Used to periodically sample the CPU TSC via a call to get_sample. We
@@ -163,7 +161,7 @@
}
/**
-@@ -442,8 +435,7 @@ static int init_stats(void)
+@@ -442,8 +435,7 @@ out:
* 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
@@ -173,7 +171,7 @@
*/
static ssize_t simple_data_read(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos, const u64 *entry)
-@@ -478,8 +470,7 @@ static ssize_t simple_data_read(struct file *filp, char __user *ubuf,
+@@ -478,8 +470,7 @@ static ssize_t simple_data_read(struct f
* 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
@@ -183,6 +181,3 @@
*/
static ssize_t simple_data_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos, u64 *entry)
---
-1.8.4.rc3
-
diff --git a/patches/hwlat-detector-Use-trace_clock_local-if-available.patch b/patches/hwlat-detector-Use-trace_clock_local-if-available.patch
index 9d7d327..bef079f 100644
--- a/patches/hwlat-detector-Use-trace_clock_local-if-available.patch
+++ b/patches/hwlat-detector-Use-trace_clock_local-if-available.patch
@@ -12,11 +12,9 @@
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
- drivers/misc/hwlat_detector.c | 34 +++++++++++++++++++++++++---------
+ drivers/misc/hwlat_detector.c | 34 +++++++++++++++++++++++++---------
1 file changed, 25 insertions(+), 9 deletions(-)
-diff --git a/drivers/misc/hwlat_detector.c b/drivers/misc/hwlat_detector.c
-index f93b8ef..d80a857 100644
--- a/drivers/misc/hwlat_detector.c
+++ b/drivers/misc/hwlat_detector.c
@@ -51,6 +51,7 @@
@@ -27,7 +25,7 @@
#define BUF_SIZE_DEFAULT 262144UL /* 8K*(sizeof(entry)) */
#define BUF_FLAGS (RB_FL_OVERWRITE) /* no block on full */
-@@ -211,6 +212,21 @@ static struct sample *buffer_get_sample(struct sample *sample)
+@@ -211,6 +212,21 @@ static struct sample *buffer_get_sample(
return sample;
}
@@ -41,7 +39,7 @@
+#else
+#define time_type u64
+#define time_get() trace_clock_local()
-+#define time_to_us(x) ((x) / 1000)
++#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
@@ -49,7 +47,7 @@
/**
* get_sample - sample the CPU TSC and look for likely hardware latencies
* @unused: This is not used but is a part of the stop_machine API
-@@ -220,23 +236,23 @@ static struct sample *buffer_get_sample(struct sample *sample)
+@@ -220,23 +236,23 @@ static struct sample *buffer_get_sample(
*/
static int get_sample(void *unused)
{
@@ -93,6 +91,3 @@
/* This shouldn't happen */
if (diff < 0) {
---
-1.8.4.rc3
-
diff --git a/patches/irq-allow-disabling-of-softirq-processing-in-irq-thread-context.patch b/patches/irq-allow-disabling-of-softirq-processing-in-irq-thread-context.patch
index 2d6f039..cb916f7 100644
--- a/patches/irq-allow-disabling-of-softirq-processing-in-irq-thread-context.patch
+++ b/patches/irq-allow-disabling-of-softirq-processing-in-irq-thread-context.patch
@@ -64,7 +64,7 @@
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
-@@ -783,7 +783,15 @@ irq_forced_thread_fn(struct irq_desc *de
+@@ -856,7 +856,15 @@ irq_forced_thread_fn(struct irq_desc *de
local_bh_disable();
ret = action->thread_fn(action->irq, action->dev_id);
irq_finalize_oneshot(desc, action);
@@ -81,7 +81,7 @@
return ret;
}
-@@ -1128,6 +1136,9 @@ __setup_irq(unsigned int irq, struct irq
+@@ -1201,6 +1209,9 @@ __setup_irq(unsigned int irq, struct irq
irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
}
diff --git a/patches/localversion.patch b/patches/localversion.patch
index 9dfd443..5dacefd 100644
--- a/patches/localversion.patch
+++ b/patches/localversion.patch
@@ -12,4 +12,4 @@
--- /dev/null
+++ b/localversion-rt
@@ -0,0 +1 @@
-+-rt6
++-rt7
diff --git a/patches/md-disable-bcache.patch b/patches/md-disable-bcache.patch
new file mode 100644
index 0000000..7b47e0d
--- /dev/null
+++ b/patches/md-disable-bcache.patch
@@ -0,0 +1,35 @@
+From a94d9b765f54e3ab9d11156c7a899c71a9185f1c Mon Sep 17 00:00:00 2001
+From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Date: Thu, 29 Aug 2013 11:48:57 +0200
+Subject: [PATCH] md: disable bcache
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+It uses anon semaphores
+|drivers/md/bcache/request.c: In function ‘cached_dev_write_complete’:
+|drivers/md/bcache/request.c:1007:2: error: implicit declaration of function ‘up_read_non_owner’ [-Werror=implicit-function-declaration]
+| up_read_non_owner(&dc->writeback_lock);
+| ^
+|drivers/md/bcache/request.c: In function ‘request_write’:
+|drivers/md/bcache/request.c:1033:2: error: implicit declaration of function ‘down_read_non_owner’ [-Werror=implicit-function-declaration]
+| down_read_non_owner(&dc->writeback_lock);
+| ^
+
+either we get rid of those or we have to introduce them…
+
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ drivers/md/bcache/Kconfig | 1 +
+ 1 file changed, 1 insertion(+)
+
+--- 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/patches/ptrace-fix-ptrace-vs-tasklist_lock-race.patch b/patches/ptrace-fix-ptrace-vs-tasklist_lock-race.patch
new file mode 100644
index 0000000..f940c45
--- /dev/null
+++ b/patches/ptrace-fix-ptrace-vs-tasklist_lock-race.patch
@@ -0,0 +1,69 @@
+From 1bd263cbd3951f8f36ee6dcfe9160dafcfdd91fe Mon Sep 17 00:00:00 2001
+From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Date: Thu, 29 Aug 2013 18:21:04 +0200
+Subject: [PATCH] ptrace: fix ptrace vs tasklist_lock race
+
+As explained by Alexander Fyodorov <halcy@yandex.ru>:
+
+|read_lock(&tasklist_lock) in ptrace_stop() is converted to mutex on RT kernel,
+|and it can remove __TASK_TRACED from task->state (by moving it to
+|task->saved_state). If parent does wait() on child followed by a sys_ptrace
+|call, the following race can happen:
+|
+|- child sets __TASK_TRACED in ptrace_stop()
+|- parent does wait() which eventually calls wait_task_stopped() and returns
+| child's pid
+|- child blocks on read_lock(&tasklist_lock) in ptrace_stop() and moves
+| __TASK_TRACED flag to saved_state
+|- parent calls sys_ptrace, which calls ptrace_check_attach() and wait_task_inactive()
+
+The patch is based on his initial patch where an additional check is
+added in case the __TASK_TRACED moved to ->saved_state. The pi_lock is
+taken in case the caller is interrupted between looking into ->state and
+->saved_state.
+
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ include/linux/sched.h | 19 ++++++++++++++++++-
+ 1 file changed, 18 insertions(+), 1 deletion(-)
+
+diff --git a/include/linux/sched.h b/include/linux/sched.h
+index e0a05de..bd60b9d 100644
+--- a/include/linux/sched.h
++++ b/include/linux/sched.h
+@@ -175,7 +175,6 @@ extern char ___assert_task_state[1 - 2*!!(
+ 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) \
+@@ -2532,6 +2531,24 @@ static inline int signal_pending_state(long state, struct task_struct *p)
+ return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
+ }
+
++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;
++}
++
+ /*
+ * cond_resched() and cond_resched_lock(): latency reduction via
+ * explicit rescheduling in places that are safe. The return
+--
+1.8.4.rc3
+
diff --git a/patches/random-make-it-work-on-rt.patch b/patches/random-make-it-work-on-rt.patch
index 2cf70ab..09accb1 100644
--- a/patches/random-make-it-work-on-rt.patch
+++ b/patches/random-make-it-work-on-rt.patch
@@ -99,7 +99,7 @@
note_interrupt(irq, desc, retval);
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
-@@ -880,6 +880,12 @@ static int irq_thread(void *data)
+@@ -953,6 +953,12 @@ static int irq_thread(void *data)
if (!noirqdebug)
note_interrupt(action->irq, desc, action_ret);
diff --git a/patches/rcu-more-swait-conversions.patch b/patches/rcu-more-swait-conversions.patch
index adb85c1..426e0a4 100644
--- a/patches/rcu-more-swait-conversions.patch
+++ b/patches/rcu-more-swait-conversions.patch
@@ -1,8 +1,19 @@
-Subject: rcu-more-swait-conversions.patch
+From eddcd14571497d3d5d6ce7df0ee1bf2ecec72292 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 31 Jul 2013 19:00:35 +0200
+Subject: [PATCH] rcu-more-swait-conversions.patch
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+
+Merged Steven's
+
+ static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp) {
+- swait_wake(&rnp->nocb_gp_wq[rnp->completed & 0x1]);
++ wake_up_all(&rnp->nocb_gp_wq[rnp->completed & 0x1]);
+ }
+
+Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/rcutree.h | 5 +++--
kernel/rcutree_plugin.h | 14 +++++++-------
@@ -43,7 +54,7 @@
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(&rnp->nocb_gp_wq[rnp->completed & 0x1]);
++ swait_wake_all(&rnp->nocb_gp_wq[rnp->completed & 0x1]);
}
/*
diff --git a/patches/series b/patches/series
index 2267ed0..317eeea 100644
--- a/patches/series
+++ b/patches/series
@@ -96,6 +96,8 @@
# PTRACE/SIGNAL crap
signal-revert-ptrace-preempt-magic.patch
+# wait for feedback
+# ptrace-fix-ptrace-vs-tasklist_lock-race.patch
# ARM lock annotation
arm-convert-boot-lock-to-raw.patch
@@ -232,6 +234,7 @@
genirq-nodebug-shirq.patch
genirq-disable-irqpoll-on-rt.patch
genirq-force-threading.patch
+genirq-do-not-invoke-the-affinity-callback-via-a-wor.patch
# DRIVERS NET
drivers-net-fix-livelock-issues.patch
@@ -610,13 +613,11 @@
# SIMPLE WAITQUEUE
wait-simple-implementation.patch
wait-simple-rework-for-completions.patch
-swait-Add-memory-barrier-before-checking-list-empty.patch
-swait-Add-smp_mb-after-setting-h-list.patch
+simple-wait-rename-and-export-the-equivalent-of-wait.patch
rcutiny-use-simple-waitqueue.patch
treercu-use-simple-waitqueue.patch
rcu-more-swait-conversions.patch
-rcu-swait-Fix-RCU-conversion-of-wake_up_all-to-swait.patch
completion-use-simple-wait-queues.patch
@@ -624,6 +625,9 @@
# Revisit: We need this in other places as well
move_sched_delayed_work_to_helper.patch
+# bcache disabled
+md-disable-bcache.patch
+
# Enable full RT
kconfig-disable-a-few-options-rt.patch
kconfig-preempt-rt-full.patch
diff --git a/patches/simple-wait-rename-and-export-the-equivalent-of-wait.patch b/patches/simple-wait-rename-and-export-the-equivalent-of-wait.patch
new file mode 100644
index 0000000..c140d82
--- /dev/null
+++ b/patches/simple-wait-rename-and-export-the-equivalent-of-wait.patch
@@ -0,0 +1,63 @@
+From 069b715a6b4f86a4a09a0be1d7156c7b388eaf2d Mon Sep 17 00:00:00 2001
+From: Paul Gortmaker <paul.gortmaker@windriver.com>
+Date: Tue, 27 Aug 2013 14:20:26 -0400
+Subject: [PATCH] simple-wait: rename and export the equivalent of
+ waitqueue_active()
+
+The function "swait_head_has_waiters()" was internalized into
+wait-simple.c but it parallels the waitqueue_active of normal
+waitqueue support. Given that there are over 150 waitqueue_active
+users in drivers/ fs/ kernel/ and the like, lets make it globally
+visible, and rename it to parallel the waitqueue_active accordingly.
+We'll need to do this if we expect to expand its usage beyond RT.
+
+Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ include/linux/wait-simple.h | 8 ++++++++
+ kernel/wait-simple.c | 10 +---------
+ 2 files changed, 9 insertions(+), 9 deletions(-)
+
+--- a/include/linux/wait-simple.h
++++ b/include/linux/wait-simple.h
+@@ -47,6 +47,14 @@ extern void swait_prepare(struct swait_h
+ 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
+ */
+--- a/kernel/wait-simple.c
++++ b/kernel/wait-simple.c
+@@ -26,14 +26,6 @@ static inline void __swait_dequeue(struc
+ list_del_init(&w->node);
+ }
+
+-/* Check whether a head has waiters enqueued */
+-static inline bool swait_head_has_waiters(struct swait_head *h)
+-{
+- /* Make sure the condition is visible before checking list_empty() */
+- smp_mb();
+- return !list_empty(&h->list);
+-}
+-
+ void __init_swait_head(struct swait_head *head, struct lock_class_key *key)
+ {
+ raw_spin_lock_init(&head->lock);
+@@ -112,7 +104,7 @@ __swait_wake(struct swait_head *head, un
+ unsigned long flags;
+ int woken;
+
+- if (!swait_head_has_waiters(head))
++ if (!swaitqueue_active(head))
+ return 0;
+
+ raw_spin_lock_irqsave(&head->lock, flags);
diff --git a/patches/softirq-disable-softirq-stacks-for-rt.patch b/patches/softirq-disable-softirq-stacks-for-rt.patch
index 0d2cbe5..65c1bf9 100644
--- a/patches/softirq-disable-softirq-stacks-for-rt.patch
+++ b/patches/softirq-disable-softirq-stacks-for-rt.patch
@@ -159,7 +159,7 @@
+#endif
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
-@@ -445,10 +445,9 @@ struct softirq_action
+@@ -446,10 +446,9 @@ struct softirq_action
void (*action)(struct softirq_action *);
};
diff --git a/patches/softirq-local-lock.patch b/patches/softirq-local-lock.patch
index 6825a0a..5c496a8 100644
--- a/patches/softirq-local-lock.patch
+++ b/patches/softirq-local-lock.patch
@@ -55,7 +55,7 @@
* Are we in NMI context?
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
-@@ -447,7 +447,13 @@ struct softirq_action
+@@ -448,7 +448,13 @@ struct softirq_action
asmlinkage void do_softirq(void);
asmlinkage void __do_softirq(void);
@@ -69,7 +69,7 @@
extern void open_softirq(int nr, void (*action)(struct softirq_action *));
extern void softirq_init(void);
extern void __raise_softirq_irqoff(unsigned int nr);
-@@ -634,6 +640,12 @@ void tasklet_hrtimer_cancel(struct taskl
+@@ -635,6 +641,12 @@ void tasklet_hrtimer_cancel(struct taskl
tasklet_kill(&ttimer->tasklet);
}
diff --git a/patches/softirq-sanitize-softirq-pending.patch b/patches/softirq-sanitize-softirq-pending.patch
index 22906fd..1e9ff82 100644
--- a/patches/softirq-sanitize-softirq-pending.patch
+++ b/patches/softirq-sanitize-softirq-pending.patch
@@ -12,7 +12,7 @@
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
-@@ -455,6 +455,8 @@ extern void __raise_softirq_irqoff(unsig
+@@ -456,6 +456,8 @@ extern void __raise_softirq_irqoff(unsig
extern void raise_softirq_irqoff(unsigned int nr);
extern void raise_softirq(unsigned int nr);
diff --git a/patches/tasklet-rt-prevent-tasklets-from-going-into-infinite-spin-in-rt.patch b/patches/tasklet-rt-prevent-tasklets-from-going-into-infinite-spin-in-rt.patch
index 23fe479..5dbdae3 100644
--- a/patches/tasklet-rt-prevent-tasklets-from-going-into-infinite-spin-in-rt.patch
+++ b/patches/tasklet-rt-prevent-tasklets-from-going-into-infinite-spin-in-rt.patch
@@ -43,7 +43,7 @@
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
-@@ -502,8 +502,9 @@ extern void __send_remote_softirq(struct
+@@ -503,8 +503,9 @@ extern void __send_remote_softirq(struct
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.
@@ -55,7 +55,7 @@
* Tasklet is strictly serialized wrt itself, but not
wrt another tasklets. If client needs some intertask synchronization,
he makes it with spinlocks.
-@@ -528,27 +529,36 @@ struct tasklet_struct name = { NULL, 0,
+@@ -529,27 +530,36 @@ struct tasklet_struct name = { NULL, 0,
enum
{
TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
@@ -98,7 +98,7 @@
#define tasklet_unlock_wait(t) do { } while (0)
#define tasklet_unlock(t) do { } while (0)
#endif
-@@ -597,17 +607,8 @@ static inline void tasklet_disable(struc
+@@ -598,17 +608,8 @@ static inline void tasklet_disable(struc
smp_mb();
}
diff --git a/patches/wait-simple-implementation.patch b/patches/wait-simple-implementation.patch
index 5e500d6..2ebd713 100644
--- a/patches/wait-simple-implementation.patch
+++ b/patches/wait-simple-implementation.patch
@@ -13,15 +13,17 @@
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+smp_mb() added by Steven Rostedt to fix a race condition with swait
+wakeups vs adding items to the list.
---
- include/linux/wait-simple.h | 231 ++++++++++++++++++++++++++++++++++++++++++++
+ include/linux/wait-simple.h | 235 ++++++++++++++++++++++++++++++++++++++++++++
kernel/Makefile | 2
kernel/wait-simple.c | 68 ++++++++++++
- 3 files changed, 300 insertions(+), 1 deletion(-)
+ 3 files changed, 304 insertions(+), 1 deletion(-)
--- /dev/null
+++ b/include/linux/wait-simple.h
-@@ -0,0 +1,231 @@
+@@ -0,0 +1,235 @@
+#ifndef _LINUX_WAIT_SIMPLE_H
+#define _LINUX_WAIT_SIMPLE_H
+
@@ -78,6 +80,8 @@
+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();
+}
+
+/*
@@ -93,6 +97,8 @@
+ */
+static inline bool swait_head_has_waiters(struct swait_head *h)
+{
++ /* Make sure the condition is visible before checking list_empty() */
++ smp_mb();
+ return !list_empty(&h->list);
+}
+
diff --git a/patches/wait-simple-rework-for-completions.patch b/patches/wait-simple-rework-for-completions.patch
index ecf8adb..98f16ad 100644
--- a/patches/wait-simple-rework-for-completions.patch
+++ b/patches/wait-simple-rework-for-completions.patch
@@ -4,9 +4,9 @@
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
- include/linux/wait-simple.h | 56 +++++++----------------------------
- kernel/wait-simple.c | 69 ++++++++++++++++++++++++++++++++++++++------
- 2 files changed, 72 insertions(+), 53 deletions(-)
+ include/linux/wait-simple.h | 60 +++++++-----------------------------
+ kernel/wait-simple.c | 73 ++++++++++++++++++++++++++++++++++++++------
+ 2 files changed, 76 insertions(+), 57 deletions(-)
--- a/include/linux/wait-simple.h
+++ b/include/linux/wait-simple.h
@@ -27,7 +27,7 @@
extern void __init_swait_head(struct swait_head *h, struct lock_class_key *key);
#define init_swait_head(swh) \
-@@ -40,59 +42,25 @@ extern void __init_swait_head(struct swa
+@@ -40,63 +42,25 @@ extern void __init_swait_head(struct swa
/*
* Waiter functions
*/
@@ -47,6 +47,8 @@
-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();
-}
-
-/*
@@ -62,6 +64,8 @@
- */
-static inline bool swait_head_has_waiters(struct swait_head *h)
-{
+- /* Make sure the condition is visible before checking list_empty() */
+- smp_mb();
- return !list_empty(&h->list);
-}
-
@@ -97,7 +101,7 @@
DEFINE_SWAITER(__wait); \
--- a/kernel/wait-simple.c
+++ b/kernel/wait-simple.c
-@@ -12,6 +12,24 @@
+@@ -12,6 +12,28 @@
#include <linux/sched.h>
#include <linux/wait-simple.h>
@@ -105,6 +109,8 @@
+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. */
@@ -116,13 +122,15 @@
+/* Check whether a head has waiters enqueued */
+static inline bool swait_head_has_waiters(struct swait_head *h)
+{
++ /* Make sure the condition is visible before checking list_empty() */
++ smp_mb();
+ return !list_empty(&h->list);
+}
+
void __init_swait_head(struct swait_head *head, struct lock_class_key *key)
{
raw_spin_lock_init(&head->lock);
-@@ -20,19 +38,31 @@ void __init_swait_head(struct swait_head
+@@ -20,19 +42,31 @@ void __init_swait_head(struct swait_head
}
EXPORT_SYMBOL(__init_swait_head);
@@ -158,7 +166,7 @@
void swait_finish(struct swait_head *head, struct swaiter *w)
{
unsigned long flags;
-@@ -46,22 +76,43 @@ void swait_finish(struct swait_head *hea
+@@ -46,22 +80,43 @@ void swait_finish(struct swait_head *hea
}
EXPORT_SYMBOL(swait_finish);
