Messages in this thread | | | Subject | Re: [PATCH 2/3] sched,fair: Fix local starvation | From | Mike Galbraith <> | Date | Sat, 21 May 2016 16:04:48 +0200 |
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On Tue, 2016-05-10 at 19:43 +0200, Peter Zijlstra wrote:
(Evolution authors must either not do patch review, or use some other mailer. Squint hard, this crud really is your patch;)
> --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > > @@ -1762,7 +1770,11 @@ void sched_ttwu_pending(void) > > > while (llist) { > > > > p = llist_entry(llist, struct task_struct, wake_entry); > > > > llist = llist_next(llist); > -> > > ttwu_do_activate(rq, p, 0, cookie); > +> > > /* > +> > > * See ttwu_queue(); we only call ttwu_queue_remote() when > +> > > * its a x-cpu wakeup. > +> > > */ > +> > > ttwu_do_activate(rq, p, WF_MIGRATED, cookie);
Wakees that were not migrated/normalized eat an unwanted min_vruntime, and likely take a size XXL latency hit. Big box running master bled profusely under heavy load until I turned TTWU_QUEUE off.
-Mike
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