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

From: Peter Zijlstra
Date: Tue Mar 24 2015 - 08:59:36 EST


On Tue, Mar 24, 2015 at 11:36:51AM +0000, Morten Rasmussen wrote:
> 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?

Duh.. I can't read it seems ;-)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/