Re: [PATCH] sched: sync with the cfs_rq when changing sched class

[Yuyang Du <yuyang.du@intel.com>]

On Thu, Aug 13, 2015 at 04:19:04PM +0900, Byungchul Park wrote:
> > >  #ifdef CONFIG_SMP
> > >  	/* synchronize task with its prev cfs_rq */
> > > -	if (!queued)
> > > -		__update_load_avg(cfs_rq->avg.last_update_time, cpu_of(rq_of(cfs_rq)),
> > > -				&se->avg, se->on_rq * scale_load_down(se->load.weight),
> > > -				cfs_rq->curr == se, NULL);
> > > -
> > > -	/* remove our load when we leave */
> > > -	cfs_rq->avg.load_avg = max_t(long, cfs_rq->avg.load_avg - se->avg.load_avg, 0);
> > > -	cfs_rq->avg.load_sum = max_t(s64, cfs_rq->avg.load_sum - se->avg.load_sum, 0);
> > > -	cfs_rq->avg.util_avg = max_t(long, cfs_rq->avg.util_avg - se->avg.util_avg, 0);
> > > -	cfs_rq->avg.util_sum = max_t(s32, cfs_rq->avg.util_sum - se->avg.util_sum, 0);
> > > +	detach_entity_load_avg(cfs_rq, se);
> > >  #endif
> > 
> > You changed the logic.
> 
> yes, i changed it. but i think that calling __update_load_avg() is not
> a problem even in case of "queued == 1". so i didn't think that change
> seriously.
> 
> wrong? :(
> 

It is not a problem, but any good or maybe any bad? And I would suggest you
add the comment I gave you.