Re: [RFCv3 PATCH 28/48] sched: Use capacity_curr to cap utilization in get_cpu_usage()

From: Morten Rasmussen
Date: Tue Mar 24 2015 - 07:36:24 EST


On Mon, Mar 23, 2015 at 04:14:00PM +0000, Peter Zijlstra wrote:
> On Wed, Feb 04, 2015 at 06:31:05PM +0000, Morten Rasmussen wrote:
>
> > @@ -4596,9 +4596,10 @@ static int get_cpu_usage(int cpu)
> > {
> > unsigned long usage = cpu_rq(cpu)->cfs.utilization_load_avg;
> > unsigned long blocked = cpu_rq(cpu)->cfs.utilization_blocked_avg;
> > + unsigned long capacity_curr = capacity_curr_of(cpu);
> >
> > - if (usage + blocked >= SCHED_LOAD_SCALE)
> > - return capacity_orig_of(cpu);
> > + if (usage + blocked >= capacity_curr)
> > + return capacity_curr;
>
> It makes more sense to do return capacity_curr_of(), since that defers
> the computation capacity_curr_of() does to the point where its actually
> required, instead of making it unconditional.

capacity_curr_of() is used in the if-condition itself as well so we need
it unconditionally. No?
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