Messages in this thread | | | Date | Wed, 27 Apr 2016 20:09:24 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v2 0/5] x86 switch_mm uninlining and IRQ improvements |
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On Tue, Apr 26, 2016 at 09:39:04AM -0700, Andy Lutomirski wrote: > 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(-)
Reviewed-by: Borislav Petkov <bp@suse.de>
There was a concern that maybe disabling IRQs in exec_mmap->activate_mm()->switch_mm() would be a little bit of a slowdown but that's not a hot path anyway.
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply.
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