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

[Juri Lelli]

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
> >