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Groups > linux.kernel > #1404920
| From | Mike Galbraith <mgalbraith@suse.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 2/3] sched,fair: Fix local starvation |
| Date | 2016-05-22 10:10 +0200 |
| Message-ID | <rBwCt-6Pw-3@gated-at.bofh.it> (permalink) |
| References | (3 earlier) <rBvwJ-5Zr-1@gated-at.bofh.it> <rBvQ6-6kR-5@gated-at.bofh.it> <rBvZL-6nY-3@gated-at.bofh.it> <rBw9r-6qU-1@gated-at.bofh.it> <rBwj7-6ub-9@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Sun, 2016-05-22 at 15:42 +0800, Wanpeng Li wrote:
> 2016-05-22 15:32 GMT+08:00 Mike Galbraith <mgalbraith@suse.de>:
> > On Sun, 2016-05-22 at 15:27 +0800, Wanpeng Li wrote:
> >
> > > What's the meaning of 'x-cpu wakeup'? ;-)
> >
> > Generally, cross CPU, as in waker/wakee reside on different CPUs,
> > but
> > in this case, it's cross socket wakeup.
>
> Do you mean wakeup wakees on remote socket don't imply
> migration/normalized, why?
Because the wakee is NOT necessarily migrated simply because it lives
in some remote cache domain. It was a simple but nasty booboo.
ttwu():
cpu = select_task_rq(p, p->wake_cpu, SD_BALANCE_WAKE, wake_flags);
if (task_cpu(p) != cpu) {
wake_flags |= WF_MIGRATED;
set_task_cpu(p, cpu);
set_task_cpu():
if (task_cpu(p) != new_cpu) {
if (p->sched_class->migrate_task_rq)
p->sched_class->migrate_task_rq(p);
^^^^^^^^^^^^^^^^^^
migrate_task_rq_fair() normalizes wakee, those wakees that did not
migrate have NOT been normalized, leaving two flavors of wakee on the
wake_list, with no discriminator. Store class information internally,
and the x-socket information disconnect evaporates.
-Mike
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Re: [PATCH 2/3] sched,fair: Fix local starvation Mike Galbraith <mgalbraith@suse.de> - 2016-05-21 16:10 +0200
Re: [PATCH 2/3] sched,fair: Fix local starvation Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-05-21 21:10 +0200
[patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-05-22 09:10 +0200
Re: [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Peter Zijlstra <peterz@infradead.org> - 2016-05-22 11:40 +0200
Re: [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-05-22 12:00 +0200
Re: [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Peter Zijlstra <peterz@infradead.org> - 2016-05-22 12:40 +0200
Re: [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Peter Zijlstra <peterz@infradead.org> - 2016-05-23 11:20 +0200
Re: [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-05-23 11:50 +0200
Re: [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Wanpeng Li <kernellwp@gmail.com> - 2016-05-23 12:20 +0200
Re: [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-05-23 12:30 +0200
Re: [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Peter Zijlstra <peterz@infradead.org> - 2016-05-23 14:30 +0200
[tip:sched/urgent] sched/core: Fix remote wakeups tip-bot for Peter Zijlstra <tipbot@zytor.com> - 2016-05-25 09:20 +0200
Re: [PATCH 2/3] sched,fair: Fix local starvation Wanpeng Li <kernellwp@gmail.com> - 2016-05-22 09:00 +0200
Re: [PATCH 2/3] sched,fair: Fix local starvation Mike Galbraith <mgalbraith@suse.de> - 2016-05-22 09:20 +0200
Re: [PATCH 2/3] sched,fair: Fix local starvation Wanpeng Li <kernellwp@gmail.com> - 2016-05-22 09:30 +0200
Re: [PATCH 2/3] sched,fair: Fix local starvation Mike Galbraith <mgalbraith@suse.de> - 2016-05-22 09:40 +0200
Re: [PATCH 2/3] sched,fair: Fix local starvation Wanpeng Li <kernellwp@gmail.com> - 2016-05-22 09:50 +0200
Re: [PATCH 2/3] sched,fair: Fix local starvation Mike Galbraith <mgalbraith@suse.de> - 2016-05-22 10:10 +0200
Re: [PATCH 2/3] sched,fair: Fix local starvation Wanpeng Li <kernellwp@gmail.com> - 2016-05-22 10:30 +0200
Re: [PATCH 2/3] sched,fair: Fix local starvation Mike Galbraith <mgalbraith@suse.de> - 2016-05-22 10:40 +0200
Re: [PATCH 2/3] sched,fair: Fix local starvation Wanpeng Li <kernellwp@gmail.com> - 2016-05-22 11:00 +0200
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