This is a note to let you know that I've just added the patch titled
sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off()
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sched-core-idle_task_exit-shouldn-t-use-switch_mm_irqs_off.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 252d2a4117bc181b287eeddf848863788da733ae Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@xxxxxxxxxx>
Date: Fri, 9 Jun 2017 11:49:15 -0700
Subject: sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off()
From: Andy Lutomirski <luto@xxxxxxxxxx>
commit 252d2a4117bc181b287eeddf848863788da733ae upstream.
idle_task_exit() can be called with IRQs on x86 on and therefore
should use switch_mm(), not switch_mm_irqs_off().
This doesn't seem to cause any problems right now, but it will
confuse my upcoming TLB flush changes. Nonetheless, I think it
should be backported because it's trivial. There won't be any
meaningful performance impact because idle_task_exit() is only
used when offlining a CPU.
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: f98db6013c55 ("sched/core: Add switch_mm_irqs_off() and use it in the scheduler")
Link: http://lkml.kernel.org/r/ca3d1a9fa93a0b49f5a8ff729eda3640fb6abdf9.1497034141.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/sched/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5206,7 +5206,7 @@ void idle_task_exit(void)
BUG_ON(cpu_online(smp_processor_id()));
if (mm != &init_mm) {
- switch_mm_irqs_off(mm, &init_mm, current);
+ switch_mm(mm, &init_mm, current);
finish_arch_post_lock_switch();
}
mmdrop(mm);
Patches currently in stable-queue which might be from luto@xxxxxxxxxx are
queue-4.4/x86-mm-sched-core-uninline-switch_mm.patch
queue-4.4/x86-mm-add-a-noinvpcid-boot-option-to-turn-off-invpcid.patch
queue-4.4/x86-irq-do-not-substract-irq_tlb_count-from-irq_call_count.patch
queue-4.4/x86-mm-if-invpcid-is-available-use-it-to-flush-global-mappings.patch
queue-4.4/x86-mm-add-invpcid-helpers.patch
queue-4.4/sched-core-add-switch_mm_irqs_off-and-use-it-in-the-scheduler.patch
queue-4.4/arm-hide-finish_arch_post_lock_switch-from-modules.patch
queue-4.4/x86-mm-sched-core-turn-off-irqs-in-switch_mm.patch
queue-4.4/mm-mmu_context-sched-core-fix-mmu_context.h-assumption.patch
queue-4.4/x86-mm-build-arch-x86-mm-tlb.c-even-on-smp.patch
queue-4.4/sched-core-idle_task_exit-shouldn-t-use-switch_mm_irqs_off.patch