Re: [patch v5 06/15] sched: log the cpu utilization at rq

Peter Zijlstra
2013-02-20T13:34:30Z

On Wed, 2013-02-20 at 17:39 +0530, Preeti U Murthy wrote:
> Hi,
>
> >> /*
> >> * This is the main, per-CPU runqueue data structure.
> >> *
> >> @@ -481,6 +484,7 @@ struct rq {
> >> #endif
> >>
> >> struct sched_avg avg;
> >> + unsigned int util;
> >> };
> >>
> >> static inline int cpu_of(struct rq *rq)
> >
> > You don't actually compute the rq utilization, you only compute the
> > utilization as per the fair class, so if there's significant RT activity
> > it'll think the cpu is under-utilized, whihc I think will result in the
> > wrong thing.
>
> Correct me if I am wrong,but isn't the current load balancer also
> disregarding the real time tasks to calculate the domain/group/cpu level
> load too?

Nope, the rt utilization affects the cpu_power, thereby correcting the
weight stuff.