Re: [PATCH 2/3] sched,fair: Fix local starvation

2016-05-22 16:39 GMT+08:00 Mike Galbraith : > On Sun, 2016-05-22 at 16:24 +0800, Wanpeng Li wrote: > >> Do all wakees live on some remote cache domain will not migrate or >> just the ones which can't find an suitable cpu in current local >> socket(failed in select_task_rq())? >

Re: [PATCH 2/3] sched,fair: Fix local starvation

2016-05-22 16:39 GMT+08:00 Mike Galbraith : > On Sun, 2016-05-22 at 16:24 +0800, Wanpeng Li wrote: > >> Do all wakees live on some remote cache domain will not migrate or >> just the ones which can't find an suitable cpu in current local >> socket(failed in select_task_rq())? > > ?? The picture I

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Sun, 2016-05-22 at 16:24 +0800, Wanpeng Li wrote: > Do all wakees live on some remote cache domain will not migrate or > just the ones which can't find an suitable cpu in current local > socket(failed in select_task_rq())? ?? The picture I drew already answered that. -Mike

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Sun, 2016-05-22 at 16:24 +0800, Wanpeng Li wrote: > Do all wakees live on some remote cache domain will not migrate or > just the ones which can't find an suitable cpu in current local > socket(failed in select_task_rq())? ?? The picture I drew already answered that. -Mike

Re: [PATCH 2/3] sched,fair: Fix local starvation

2016-05-22 16:04 GMT+08:00 Mike Galbraith : > On Sun, 2016-05-22 at 15:42 +0800, Wanpeng Li wrote: >> 2016-05-22 15:32 GMT+08:00 Mike Galbraith : >> > On Sun, 2016-05-22 at 15:27 +0800, Wanpeng Li wrote: >> > >> > > What's the meaning of 'x-cpu wakeup'? ;-)

Re: [PATCH 2/3] sched,fair: Fix local starvation

2016-05-22 16:04 GMT+08:00 Mike Galbraith : > On Sun, 2016-05-22 at 15:42 +0800, Wanpeng Li wrote: >> 2016-05-22 15:32 GMT+08:00 Mike Galbraith : >> > 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

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Sun, 2016-05-22 at 15:42 +0800, Wanpeng Li wrote: > 2016-05-22 15:32 GMT+08:00 Mike Galbraith : > > 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

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Sun, 2016-05-22 at 15:42 +0800, Wanpeng Li wrote: > 2016-05-22 15:32 GMT+08:00 Mike Galbraith : > > 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

Re: [PATCH 2/3] sched,fair: Fix local starvation

2016-05-22 15:32 GMT+08:00 Mike Galbraith : > 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

Re: [PATCH 2/3] sched,fair: Fix local starvation

2016-05-22 15:32 GMT+08:00 Mike Galbraith : > 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

Re: [PATCH 2/3] sched,fair: Fix local starvation

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. -Mike

Re: [PATCH 2/3] sched,fair: Fix local starvation

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. -Mike

Re: [PATCH 2/3] sched,fair: Fix local starvation

2016-05-22 15:15 GMT+08:00 Mike Galbraith : > On Sun, 2016-05-22 at 14:50 +0800, Wanpeng Li wrote: >> 2016-05-21 22:04 GMT+08:00 Mike Galbraith : >> > On Tue, 2016-05-10 at 19:43 +0200, Peter Zijlstra wrote: >> > >> > (Evolution authors must either not do

Re: [PATCH 2/3] sched,fair: Fix local starvation

2016-05-22 15:15 GMT+08:00 Mike Galbraith : > On Sun, 2016-05-22 at 14:50 +0800, Wanpeng Li wrote: >> 2016-05-21 22:04 GMT+08:00 Mike Galbraith : >> > On Tue, 2016-05-10 at 19:43 +0200, Peter Zijlstra wrote: >> > >> > (Evolution authors must either not do patch review, or use some other >> >

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Sun, 2016-05-22 at 14:50 +0800, Wanpeng Li wrote: > 2016-05-21 22:04 GMT+08:00 Mike Galbraith : > > 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

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Sun, 2016-05-22 at 14:50 +0800, Wanpeng Li wrote: > 2016-05-21 22:04 GMT+08:00 Mike Galbraith : > > 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;)

Re: [PATCH 2/3] sched,fair: Fix local starvation

2016-05-21 22:04 GMT+08:00 Mike Galbraith : > 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 >> +++

Re: [PATCH 2/3] sched,fair: Fix local starvation

2016-05-21 22:04 GMT+08:00 Mike Galbraith : > 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 >>

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Sat, 2016-05-21 at 16:04 +0200, Mike Galbraith wrote: > 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. The below made big box a happy

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Sat, 2016-05-21 at 16:04 +0200, Mike Galbraith wrote: > 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. The below made big box a happy

Re: [PATCH 2/3] sched,fair: Fix local starvation

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)

Re: [PATCH 2/3] sched,fair: Fix local starvation

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)

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Tue, 10 May, at 07:43:16PM, Peter Zijlstra wrote: > Mike reported that the recent commit 3a47d5124a95 ("sched/fair: Fix > fairness issue on migration") broke interactivity and the signal > starve test. > > The problem is that I assumed ENQUEUE_WAKING was only set when we do a > cross-cpu

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Tue, 10 May, at 07:43:16PM, Peter Zijlstra wrote: > Mike reported that the recent commit 3a47d5124a95 ("sched/fair: Fix > fairness issue on migration") broke interactivity and the signal > starve test. > > The problem is that I assumed ENQUEUE_WAKING was only set when we do a > cross-cpu

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Tue, May 10, 2016 at 10:21:39PM +0200, Ingo Molnar wrote: > > * Peter Zijlstra wrote: > > > Mike reported that the recent commit 3a47d5124a95 ("sched/fair: Fix > > fairness issue on migration") broke interactivity and the signal > > starve test. > > This looks pretty

Re: [PATCH 2/3] sched,fair: Fix local starvation

On Tue, May 10, 2016 at 10:21:39PM +0200, Ingo Molnar wrote: > > * Peter Zijlstra wrote: > > > Mike reported that the recent commit 3a47d5124a95 ("sched/fair: Fix > > fairness issue on migration") broke interactivity and the signal > > starve test. > > This looks pretty dangerous for v4.6 -

Re: [PATCH 2/3] sched,fair: Fix local starvation

* Peter Zijlstra wrote: > Mike reported that the recent commit 3a47d5124a95 ("sched/fair: Fix > fairness issue on migration") broke interactivity and the signal > starve test. This looks pretty dangerous for v4.6 - how about simply reverting in 3a47d5124a95 and

Re: [PATCH 2/3] sched,fair: Fix local starvation

* Peter Zijlstra wrote: > Mike reported that the recent commit 3a47d5124a95 ("sched/fair: Fix > fairness issue on migration") broke interactivity and the signal > starve test. This looks pretty dangerous for v4.6 - how about simply reverting in 3a47d5124a95 and re-trying in v4.7? Thanks,

[PATCH 2/3] sched,fair: Fix local starvation

Mike reported that the recent commit 3a47d5124a95 ("sched/fair: Fix fairness issue on migration") broke interactivity and the signal starve test. The problem is that I assumed ENQUEUE_WAKING was only set when we do a cross-cpu wakeup (migration), which isn't true. This means we now destroy the

[PATCH 2/3] sched,fair: Fix local starvation

Mike reported that the recent commit 3a47d5124a95 ("sched/fair: Fix fairness issue on migration") broke interactivity and the signal starve test. The problem is that I assumed ENQUEUE_WAKING was only set when we do a cross-cpu wakeup (migration), which isn't true. This means we now destroy the