Re: [PATCH 0/4] Powerpc: Better preemption for shared processor

From: Srikar Dronamraju
Date: Thu Oct 29 2020 - 03:56:50 EST


* Waiman Long <longman@xxxxxxxxxx> [2020-10-28 20:01:30]:

> > Srikar Dronamraju (4):
> > powerpc: Refactor is_kvm_guest declaration to new header
> > powerpc: Rename is_kvm_guest to check_kvm_guest
> > powerpc: Reintroduce is_kvm_guest
> > powerpc/paravirt: Use is_kvm_guest in vcpu_is_preempted
> >
> > arch/powerpc/include/asm/firmware.h | 6 ------
> > arch/powerpc/include/asm/kvm_guest.h | 25 +++++++++++++++++++++++++
> > arch/powerpc/include/asm/kvm_para.h | 2 +-
> > arch/powerpc/include/asm/paravirt.h | 18 ++++++++++++++++++
> > arch/powerpc/kernel/firmware.c | 5 ++++-
> > arch/powerpc/platforms/pseries/smp.c | 3 ++-
> > 6 files changed, 50 insertions(+), 9 deletions(-)
> > create mode 100644 arch/powerpc/include/asm/kvm_guest.h
> >
> This patch series looks good to me and the performance is nice too.
>
> Acked-by: Waiman Long <longman@xxxxxxxxxx>

Thank you.

>
> Just curious, is the performance mainly from the use of static_branch
> (patches 1 - 3) or from reducing call to yield_count_of().

Because of the reduced call to yield_count

>
> Cheers,
> Longman
>

--
Thanks and Regards
Srikar Dronamraju