Re: [RFC PATCH 4/5] sched/events: Introduce sched_entity load tracking trace event

[Dietmar Eggemann]

On 03/28/2017 10:05 AM, Peter Zijlstra wrote:
> On Tue, Mar 28, 2017 at 07:35:40AM +0100, Dietmar Eggemann wrote:
> > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> > index 04d4f81b96ae..d1dcb19f5b55 100644
> > --- a/kernel/sched/fair.c
> > +++ b/kernel/sched/fair.c
> > @@ -2940,6 +2940,8 @@ __update_load_avg(u64 now, int cpu, struct sched_avg *sa,
> >
> >  	if (cfs_rq)
> >  		trace_sched_load_cfs_rq(cfs_rq);
> > +	else
> > +		trace_sched_load_se(container_of(sa, struct sched_entity, avg));
> >
> >  	return decayed;
> >  }
> > @@ -3162,6 +3164,7 @@ static inline int propagate_entity_load_avg(struct sched_entity *se)
> >  	update_tg_cfs_load(cfs_rq, se);
> >
> >  	trace_sched_load_cfs_rq(cfs_rq);
> > +	trace_sched_load_se(se);
> >
> >  	return 1;
> >  }
>
> Having back-to-back tracepoints is disgusting.

Yeah, but avoiding putting them like this is hard since the calls to 
update_tg_cfs_util() and update_tg_cfs_load() inside 
propagate_entity_load_avg() refresh util for the cfs_rq and the se 
respectively load (and runnable_load).