[PATCH v2 0/5] x86 switch_mm uninlining and IRQ improvements

From: Andy Lutomirski
Date: Tue Apr 26 2016 - 12:39:16 EST


Hi all-

I've been playing with context switching lately, and I'm going to start
sending out some of the patches that should be mostly self-contained and
ready for -tip.

Here's a little batch to start improving switch_mm. It uninlines it
and makes it run with IRQs off. (AFAICT everyone who's modified it
thought it ran with IRQs off, but that's not always the case. I
don't know of any bugs that this fixes, but it'll be needed for PCID
to avoid introducing really nasty races.)

This may also help a bit with FSGSBASE -- not sure yet. It certainly
won't hurt.

It contains a trivial off-topic ARM patch to avoid breaking the build.

Andy Lutomirski (5):
arm: Include linux/preempt.h from asm/mmu_context.h
sched: Add switch_mm_irqs_off and use it in the scheduler
x86/mm: Build arch/x86/mm/tlb.c even on !SMP
x86/mm: Uninline switch_mm
x86/mm: Turn off IRQs in switch_mm

arch/arm/include/asm/mmu_context.h | 1 +
arch/x86/include/asm/mmu_context.h | 101 ++------------------------------
arch/x86/mm/Makefile | 3 +-
arch/x86/mm/tlb.c | 116 +++++++++++++++++++++++++++++++++++++
include/linux/mmu_context.h | 7 +++
kernel/sched/core.c | 6 +-
6 files changed, 133 insertions(+), 101 deletions(-)

--
2.5.5