This is a note to let you know that I've just added the patch titled
sched/core: Add switch_mm_irqs_off() and use it in the scheduler
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-add-switch_mm_irqs_off-and-use-it-in-the-scheduler.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 f98db6013c557c216da5038d9c52045be55cd039 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@xxxxxxxxxx>
Date: Tue, 26 Apr 2016 09:39:06 -0700
Subject: sched/core: Add switch_mm_irqs_off() and use it in the scheduler
From: Andy Lutomirski <luto@xxxxxxxxxx>
commit f98db6013c557c216da5038d9c52045be55cd039 upstream.
By default, this is the same thing as switch_mm().
x86 will override it as an optimization.
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/df401df47bdd6be3e389c6f1e3f5310d70e81b2c.1461688545.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/mmu_context.h | 7 +++++++
kernel/sched/core.c | 6 +++---
2 files changed, 10 insertions(+), 3 deletions(-)
--- a/include/linux/mmu_context.h
+++ b/include/linux/mmu_context.h
@@ -1,9 +1,16 @@
#ifndef _LINUX_MMU_CONTEXT_H
#define _LINUX_MMU_CONTEXT_H
+#include <asm/mmu_context.h>
+
struct mm_struct;
void use_mm(struct mm_struct *mm);
void unuse_mm(struct mm_struct *mm);
+/* Architectures that care about IRQ state in switch_mm can override this. */
+#ifndef switch_mm_irqs_off
+# define switch_mm_irqs_off switch_mm
+#endif
+
#endif
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -32,7 +32,7 @@
#include <linux/init.h>
#include <linux/uaccess.h>
#include <linux/highmem.h>
-#include <asm/mmu_context.h>
+#include <linux/mmu_context.h>
#include <linux/interrupt.h>
#include <linux/capability.h>
#include <linux/completion.h>
@@ -2708,7 +2708,7 @@ context_switch(struct rq *rq, struct tas
atomic_inc(&oldmm->mm_count);
enter_lazy_tlb(oldmm, next);
} else
- switch_mm(oldmm, mm, next);
+ switch_mm_irqs_off(oldmm, mm, next);
if (!prev->mm) {
prev->active_mm = NULL;
@@ -5206,7 +5206,7 @@ void idle_task_exit(void)
BUG_ON(cpu_online(smp_processor_id()));
if (mm != &init_mm) {
- switch_mm(mm, &init_mm, current);
+ switch_mm_irqs_off(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