Messages in this thread | | | Subject | Re: sched: how to pick runqueue when checking task hot? | From | Mike Galbraith <> | Date | Fri, 06 Jun 2014 13:16:23 +0200 |
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On Fri, 2014-06-06 at 12:15 +0200, Peter Zijlstra wrote:
> > --- a/kernel/sched/fair.c Fri Jun 6 12:37:37 2014 > > +++ b/kernel/sched/fair.c Fri Jun 6 14:32:34 2014 > > @@ -5051,7 +5051,7 @@ task_hot(struct task_struct *p, u64 now) > > /* > > * Buddy candidates are cache hot: > > */ > > - if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && > > + if (sched_feat(CACHE_HOT_BUDDY) && task_rq(p)->nr_running && > > (&p->se == cfs_rq_of(&p->se)->next || > > &p->se == cfs_rq_of(&p->se)->last)) > > return 1; > > That does appear to make more sense indeed, seeing how buddies are pairs > of tasks, so protecting a lone task doesn't make sense. > > > Mike, how did you intend this code to work?
IIRC, this_rq()->nr_running was to say if we're idle, we don't care that it's last/next, pull it. Not sure I'm the one who did that, but could be, I didn't look.
-Mike
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