We gain nothing by having the core code enable IRQs right before calling
activate_mm() only for us to turn them right back off again in switch_mm().
This will save a few cycles, so execve() should be blazingly fast with this
patch applied!
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/Kconfig | 1 +
arch/x86/include/asm/mmu_context.h | 8 ++++----
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5060c38bf560..908a596619f2 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -119,6 +119,7 @@ config X86
select ARCH_WANT_LD_ORPHAN_WARN
select ARCH_WANTS_THP_SWAP if X86_64
select ARCH_HAS_PARANOID_L1D_FLUSH
+ select ARCH_WANT_IRQS_OFF_ACTIVATE_MM
select BUILDTIME_TABLE_SORT
select CLKEVT_I8253
select CLOCKSOURCE_VALIDATE_LAST_CYCLE
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 2ca4fc4a8a0a..f028f1b68bc0 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -132,10 +132,10 @@ extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk);
#define switch_mm_irqs_off switch_mm_irqs_off
-#define activate_mm(prev, next) \
-do { \
- paravirt_activate_mm((prev), (next)); \
- switch_mm((prev), (next), NULL); \
+#define activate_mm(prev, next) \
+do { \
+ paravirt_activate_mm((prev), (next)); \
+ switch_mm_irqs_off((prev), (next), NULL); \
} while (0);
#ifdef CONFIG_X86_32
--
2.33.1
