Re: [PATCH v2] sched/nohz: Optimize get_nohz_timer_target()

From: Wanpeng Li
Date: Mon Jan 06 2020 - 01:21:26 EST

Hi Thomas,
On Wed, 23 Oct 2019 at 16:29, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> On Wed, 23 Oct 2019, Wanpeng Li wrote:
> > I didn't see your refactor to get_nohz_timer_target() which you
> > mentioned in IRC after four months, I can observe cyclictest drop from
> > 4~5us to 8us in kvm guest(we offload the lapic timer emulation to
> > housekeeping cpu to avoid timer fire external interrupt on the pCPU
> > which vCPU resident incur a vCPU vmexit) w/o this patch in the case of
> > there is no busy housekeeping cpu. The score can be recovered after I
> > give stress to create a busy housekeeping cpu.
> >
> > Could you consider applying this patch for temporary since I'm not
> > sure when the refactor can be ready.
> Yeah. It's delayed (again).... Will pick that up.

I didn't find WIP tag for this work after ~half year since v4 was
posted Could you apply this patch
for temporary because the completion time of refactor is not