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

From: Rafael J. Wysocki
Date: Mon Sep 12 2016 - 18:19:53 EST


On Wednesday, August 31, 2016 04:34:37 PM Peter Zijlstra wrote:
> 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

OK, thanks!

Applied.