Re: [PATCH v6 04/11] cpufreq/schedutil: use rt utilization tracking

From: Peter Zijlstra
Date: Fri Jun 22 2018 - 07:41:50 EST


On Fri, Jun 22, 2018 at 10:10:32AM +0200, Vincent Guittot wrote:
> On Thu, 21 Jun 2018 at 20:57, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> >
> > > So this (and the dl etc. equivalents) result in exactly the problems
> > > complained about last time, no?
> > >
> > > What I proposed was something along the lines of:
> > >
> > > util = 1024 * sg_cpu->util_cfs;
> > > util /= (1024 - (sg_cpu->util_rt + sg_cpu->util_dl + ...));
> > >
> > > return min(sg_cpu->max, util + sg_cpu->bw_dl);
>
> I see that you use sg_cpu->util_dl and sg_cpu->bw_dl in your equation
> above but this patch 04 only adds rt util_avg and the dl util_avg has
> not been added yet.
> dl util_avg is added in patch 6
> So for this patch, we are only using sg_cpu->bw_dl

Yeah, not the point really.

It is about how we're going to use the (rt,dl,irq etc..) util values,
more than which particular one was introduced here.

I'm just not a big fan of the whole: freq := cfs_util + rt_util thing
(as would be obvious by now).