Re: [PATCH v3] sched/cpufreq: optimize cpufreq update kicker to avoid update multiple times

From: Peter Zijlstra
Date: Mon Apr 25 2016 - 10:31:44 EST


On Fri, Apr 22, 2016 at 02:04:56PM +0200, Rafael J. Wysocki wrote:
> [Added linux-pm to the CC - can you please do so for PM-related patches in
> the future?]
>
> On 4/22/2016 11:07 AM, Wanpeng Li wrote:
> >From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
> >
> >Sometimes delta_exec is 0 due to update_curr() is called multiple times,
> >this is captured by:
> >
> > u64 delta_exec = rq_clock_task(rq) - curr->se.exec_start;
> >
> >This patch optimizes the cpufreq update kicker by bailing out when nothing
> >changed, it will benefit the upcoming schedutil, since otherwise it will
> >(over)react to the special util/max combination.
> >
> >Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
>
> The changelog looks better now, thanks!
>
> Peter, do I think correctly that you're going to take care of this one? Or
> do you want me to take it?

YEah, looks fine. I'll take it.

Thanks!