Re: [RFC PATCH v1 5/8] sched/cpufreq_schedutil: always consider all CPUs when deciding next freq

Juri Lelli
2017-07-11T17:18:42Z

On 11/07/17 18:17, Peter Zijlstra wrote:
> On Wed, Jul 05, 2017 at 09:59:02AM +0100, Juri Lelli wrote:
> > delta_ns = time - j_sg_cpu->last_update;
> > if (delta_ns > TICK_NSEC) {
> > j_sg_cpu->iowait_boost = 0;
> > - continue;
> > + j_sg_cpu->util_cfs = 0;
>
> this is slighly confusing. Is this because we might not 'continue' with
> the new code?
>

This is because, after TICK_NSEC, we only want to discard CFS
contribution and (yes) continue (so don't take into account
j_sg_cpu contribution) if DEADLINE contribution is zero as well.

> > + if (j_sg_cpu->util_dl == 0)
> > + continue;
> > }
> > +

With this change we might not continue if some DEADLINE utilization is
present for j_sg_cpu.

> > if (j_sg_cpu->flags & SCHED_CPUFREQ_RT)
> > return policy->cpuinfo.max_freq;
> >
> > --
> > 2.11.0
> >