| Subject: cpumask: Disable CONFIG_CPUMASK_OFFSTACK for RT |
| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Wed, 14 Dec 2011 01:03:49 +0100 |
| |
| There are "valid" GFP_ATOMIC allocations such as |
| |
| |BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:931 |
| |in_atomic(): 1, irqs_disabled(): 0, pid: 2130, name: tar |
| |1 lock held by tar/2130: |
| | #0: (&mm->mmap_sem){++++++}, at: [<ffffffff811d4e89>] SyS_brk+0x39/0x190 |
| |Preemption disabled at:[<ffffffff81063048>] flush_tlb_mm_range+0x28/0x350 |
| | |
| |CPU: 1 PID: 2130 Comm: tar Tainted: G W 4.8.2-rt2+ #747 |
| |Call Trace: |
| | [<ffffffff814d52dc>] dump_stack+0x86/0xca |
| | [<ffffffff810a26fb>] ___might_sleep+0x14b/0x240 |
| | [<ffffffff819bc1d4>] rt_spin_lock+0x24/0x60 |
| | [<ffffffff81194fba>] get_page_from_freelist+0x83a/0x11b0 |
| | [<ffffffff81195e8b>] __alloc_pages_nodemask+0x15b/0x1190 |
| | [<ffffffff811f0b81>] alloc_pages_current+0xa1/0x1f0 |
| | [<ffffffff811f7df5>] new_slab+0x3e5/0x690 |
| | [<ffffffff811fb0d5>] ___slab_alloc+0x495/0x660 |
| | [<ffffffff811fb311>] __slab_alloc.isra.79+0x71/0xc0 |
| | [<ffffffff811fb447>] __kmalloc_node+0xe7/0x240 |
| | [<ffffffff814d4ee0>] alloc_cpumask_var_node+0x20/0x50 |
| | [<ffffffff814d4f3e>] alloc_cpumask_var+0xe/0x10 |
| | [<ffffffff810430c1>] native_send_call_func_ipi+0x21/0x130 |
| | [<ffffffff8111c13f>] smp_call_function_many+0x22f/0x370 |
| | [<ffffffff81062b64>] native_flush_tlb_others+0x1a4/0x3a0 |
| | [<ffffffff8106309b>] flush_tlb_mm_range+0x7b/0x350 |
| | [<ffffffff811c88e2>] tlb_flush_mmu_tlbonly+0x62/0xd0 |
| | [<ffffffff811c9af4>] tlb_finish_mmu+0x14/0x50 |
| | [<ffffffff811d1c84>] unmap_region+0xe4/0x110 |
| | [<ffffffff811d3db3>] do_munmap+0x293/0x470 |
| | [<ffffffff811d4f8c>] SyS_brk+0x13c/0x190 |
| | [<ffffffff810032e2>] do_fast_syscall_32+0xb2/0x2f0 |
| | [<ffffffff819be181>] entry_SYSENTER_compat+0x51/0x60 |
| |
| which forbid allocations at run-time. |
| |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| --- |
| arch/x86/Kconfig | 2 +- |
| lib/Kconfig | 1 + |
| 2 files changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/arch/x86/Kconfig |
| +++ b/arch/x86/Kconfig |
| @@ -945,7 +945,7 @@ config IOMMU_HELPER |
| 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. |
| --- a/lib/Kconfig |
| +++ b/lib/Kconfig |
| @@ -428,6 +428,7 @@ config CHECK_SIGNATURE |
| |
| 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 |
