lkml.org 
[lkml]   [2014]   [Jun]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: sched: how to pick runqueue when checking task hot?
From
Date
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



\
 
 \ /
  Last update: 2014-06-06 13:41    [W:0.035 / U:1.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site