Messages in this thread | | | Date | Fri, 10 Mar 2017 21:23:43 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH v2 0/3] x86/process: Optimize __switch_to_xtra() |
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On Wed, 8 Mar 2017, Kyle Huey wrote:
> On Tue, Feb 28, 2017 at 10:33 AM, Kyle Huey <me@kylehuey.com> wrote: > > On Tue, Feb 14, 2017 at 12:11 AM, Kyle Huey <me@kylehuey.com> wrote: > >> GCC generates lousy code in __switch_to_xtra. This patch series is an > >> updated version of tglx's patches from last year > >> (https://lkml.org/lkml/2016/12/15/432) that address review comments. > >> > >> Since v1: > >> Part 1 - x86/process: Optimize TIF checks in __switch_to_xtra() > >> - READ_ONCE annotations added as requested by Andy Lutomirski > >> > >> Part 2 - x86/process: Correct and optimize TIF_BLOCKSTEP switch > >> - DEBUGCTLMSR_BTF is now modified when either the previous or > >> next or both tasks use it, because the MSR is "highly magical". > >> > >> Part 3 - x86/process: Optimize TIF_NOTSC switch > >> - Unchanged > >> > >> I didn't introduce a cpufeature for blockstep because that would > >> add additional overhead compared to the existing code, where it's > >> generally known at compile time that blockstep is supported. Perhaps > >> we should just BUG_ON(!arch_has_block_step()) here if we really > >> care to check anything. > >> > >> arch/x86/include/asm/msr-index.h | 1 + > >> arch/x86/include/asm/tlbflush.h | 10 ++++++++++ > >> arch/x86/kernel/process.c | 76 +++++++++++++++++++++++++++++++++++----------------------------------------- > >> 3 files changed, 46 insertions(+), 41 deletions(-) > >> > > > > Has anyone had a change to look at these? > > Maybe now that the 4.11 merge window is closed? :)
Yes. It's on my radar, but I'm swamped with regressions. Next week should be more time for that.
Thanks,
tglx
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