On Mon, Jun 20, 2016 at 12:35:59PM +0100, Dietmar Eggemann wrote:
>
>
> On 17/06/16 17:18, Peter Zijlstra wrote:
> > On Fri, Jun 17, 2016 at 06:02:39PM +0200, Peter Zijlstra wrote:
> >> So yes, ho-humm, how to go about doing that bestest. Lemme have a play.
> >
> > This is what I came up with, not entirely pretty, but I suppose it'll
> > have to do.
> >
> > ---
> > --- a/kernel/sched/fair.c
> > +++ b/kernel/sched/fair.c
> > @@ -724,6 +724,7 @@ void post_init_entity_util_avg(struct sc
> > struct cfs_rq *cfs_rq = cfs_rq_of(se);
> > struct sched_avg *sa = &se->avg;
> > long cap = (long)(SCHED_CAPACITY_SCALE - cfs_rq->avg.util_avg) / 2;
> > + u64 now = cfs_rq_clock_task(cfs_rq);
> >
> > if (cap > 0) {
> > if (cfs_rq->avg.util_avg != 0) {
> > @@ -738,7 +739,20 @@ void post_init_entity_util_avg(struct sc
> > sa->util_sum = sa->util_avg * LOAD_AVG_MAX;
> > }
> >
> > - update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq, false);
> > + if (entity_is_task(se)) {
> > + struct task_struct *p = task_of(se);
> > + if (p->sched_class != &fair_sched_class) {
> > + /*
> > + * For !fair tasks do attach_entity_load_avg()
> > + * followed by detach_entity_load_avg() as per
> > + * switched_from_fair().
> > + */
> > + se->avg.last_update_time = now;
> > + return;
> > + }
> > + }
> > +
> > + update_cfs_rq_load_avg(now, cfs_rq, false);
> > attach_entity_load_avg(cfs_rq, se);
> > }
> >
> >
>
> Doesn't a sleeping !fair_sched_class task which switches to fair uses
> try_to_wake_up() rather than wake_up_new_task() so it won't go through
> post_init_entity_util_avg()?
Its switched_to_fair() that'll fix that up.
