Re: [PATCH 1/2] sched: cpufreq: ignore SMT when determining max cpu capacity

From: Peter Zijlstra
Date: Wed Aug 31 2016 - 10:34:53 EST


On Wed, Aug 31, 2016 at 03:27:30AM +0200, Rafael J. Wysocki wrote:
> On Friday, August 26, 2016 11:40:47 AM Steve Muckle wrote:
> > PELT does not consider SMT when scaling its utilization values via
> > arch_scale_cpu_capacity(). The value in rq->cpu_capacity_orig does
> > take SMT into consideration though and therefore may be smaller than
> > the utilization reported by PELT.
> >
> > On an Intel i7-3630QM for example rq->cpu_capacity_orig is 589 but
> > util_avg scales up to 1024. This means that a 50% utilized CPU will show
> > up in schedutil as ~86% busy.
> >
> > Fix this by using the same CPU scaling value in schedutil as that which
> > is used by PELT.
> >
> > Signed-off-by: Steve Muckle <smuckle@xxxxxxxxxx>
>
> This is fine by me.
>
> Peter, any objections?

No, looks good. Thanks