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Groups > linux.kernel > #1244559
| From | Yuyang Du <yuyang.du@intel.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: 4.3 group scheduling regression |
| Date | 2015-10-12 12:10 +0200 |
| Message-ID | <qiIdl-488-13@gated-at.bofh.it> (permalink) |
| References | (5 earlier) <qiFIu-pP-7@gated-at.bofh.it> <qiG1P-MT-7@gated-at.bofh.it> <qiGld-1p0-15@gated-at.bofh.it> <qiGXT-28r-5@gated-at.bofh.it> <qiHqW-2Xd-19@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Mon, Oct 12, 2015 at 11:12:06AM +0200, Peter Zijlstra wrote: > On Mon, Oct 12, 2015 at 08:53:51AM +0800, Yuyang Du wrote: > > Good morning, Peter. > > > > On Mon, Oct 12, 2015 at 10:04:07AM +0200, Peter Zijlstra wrote: > > > On Mon, Oct 12, 2015 at 09:44:57AM +0200, Mike Galbraith wrote: > > > > > > > It's odd to me that things look pretty much the same good/bad tree with > > > > hogs vs hogs or hogs vs tbench (with top anyway, just adding up times). > > > > Seems Xorg+mplayer more or less playing cross group ping-pong must be > > > > the BadThing trigger. > > > > > > Ohh, wait, Xorg and mplayer are _not_ in the same group? I was assuming > > > you had your entire user session in 1 (auto) group and was competing > > > against 8 manual cgroups. > > > > > > So how exactly are things configured? > > > > Hmm... my impression is the naughty boy mplayer (+Xorg) isn't favored, due > > to the per CPU group entity share distribution. Let me dig more. > > So in the old code we had 'magic' to deal with the case where a cgroup > was consuming less than 1 cpu's worth of runtime. For example, a single > task running in the group. > > In that scenario it might be possible that the group entity weight: > > se->weight = (tg->shares * cfs_rq->weight) / tg->weight; > > Strongly deviates from the tg->shares; you want the single task reflect > the full group shares to the next level; due to the whole distributed > approximation stuff. Yeah, I thought so. > I see you've deleted all that code; see the former > __update_group_entity_contrib(). Probably not there, it actually was an icky way to adjust things. > It could be that we need to bring that back. But let me think a little > bit more on this.. I'm having a hard time waking :/ I am guessing it is in calc_tg_weight(), and naughty boys do make them more favored, what a reality... Mike, beg you test the following? -- diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 4df37a4..b184da0 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2370,7 +2370,7 @@ static inline long calc_tg_weight(struct task_group *tg, struct cfs_rq *cfs_rq) */ tg_weight = atomic_long_read(&tg->load_avg); tg_weight -= cfs_rq->tg_load_avg_contrib; - tg_weight += cfs_rq_load_avg(cfs_rq); + tg_weight += cfs_rq->load.weight; return tg_weight; } @@ -2380,7 +2380,7 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) long tg_weight, load, shares; tg_weight = calc_tg_weight(tg, cfs_rq); - load = cfs_rq_load_avg(cfs_rq); + load = cfs_rq->load.weight; shares = (tg->shares * load); if (tg_weight) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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Re: CFS scheduler unfairly prefers pinned tasks Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-06 04:50 +0200
Re: CFS scheduler unfairly prefers pinned tasks paul.szabo@sydney.edu.au - 2015-10-06 12:10 +0200
Re: CFS scheduler unfairly prefers pinned tasks Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-06 14:20 +0200
Re: CFS scheduler unfairly prefers pinned tasks paul.szabo@sydney.edu.au - 2015-10-06 22:50 +0200
Re: CFS scheduler unfairly prefers pinned tasks Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-07 03:30 +0200
Re: CFS scheduler unfairly prefers pinned tasks Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-08 10:30 +0200
Re: CFS scheduler unfairly prefers pinned tasks paul.szabo@sydney.edu.au - 2015-10-08 13:00 +0200
Re: CFS scheduler unfairly prefers pinned tasks Peter Zijlstra <peterz@infradead.org> - 2015-10-08 13:30 +0200
[patch] sched: disable task group re-weighting on the desktop Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-10 15:30 +0200
Re: [patch] sched: disable task group re-weighting on the desktop Peter Zijlstra <peterz@infradead.org> - 2015-10-10 19:10 +0200
Re: [patch] sched: disable task group re-weighting on the desktop Peter Zijlstra <peterz@infradead.org> - 2015-10-10 19:20 +0200
Re: [patch] sched: disable task group re-weighting on the desktop Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-11 04:30 +0200
4.3 group scheduling regression Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-11 19:50 +0200
Re: 4.3 group scheduling regression Peter Zijlstra <peterz@infradead.org> - 2015-10-12 09:30 +0200
Re: 4.3 group scheduling regression Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-12 09:50 +0200
Re: 4.3 group scheduling regression Peter Zijlstra <peterz@infradead.org> - 2015-10-12 10:10 +0200
Re: 4.3 group scheduling regression Yuyang Du <yuyang.du@intel.com> - 2015-10-12 10:50 +0200
Re: 4.3 group scheduling regression Peter Zijlstra <peterz@infradead.org> - 2015-10-12 11:20 +0200
Re: 4.3 group scheduling regression Yuyang Du <yuyang.du@intel.com> - 2015-10-12 12:10 +0200
Re: 4.3 group scheduling regression Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-12 12:30 +0200
Re: 4.3 group scheduling regression Yuyang Du <yuyang.du@intel.com> - 2015-10-13 05:50 +0200
Re: 4.3 group scheduling regression Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-13 06:10 +0200
Re: 4.3 group scheduling regression Yuyang Du <yuyang.du@intel.com> - 2015-10-13 06:40 +0200
Re: 4.3 group scheduling regression Peter Zijlstra <peterz@infradead.org> - 2015-10-13 10:10 +0200
Re: 4.3 group scheduling regression Peter Zijlstra <peterz@infradead.org> - 2015-10-13 10:20 +0200
Re: 4.3 group scheduling regression Yuyang Du <yuyang.du@intel.com> - 2015-10-13 10:30 +0200
Re: 4.3 group scheduling regression Yuyang Du <yuyang.du@intel.com> - 2015-10-13 10:30 +0200
Re: 4.3 group scheduling regression Peter Zijlstra <peterz@infradead.org> - 2015-10-12 13:50 +0200
Re: 4.3 group scheduling regression Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-13 04:30 +0200
Re: 4.3 group scheduling regression Yuyang Du <yuyang.du@intel.com> - 2015-10-13 05:30 +0200
Re: 4.3 group scheduling regression Peter Zijlstra <peterz@infradead.org> - 2015-10-13 10:10 +0200
Re: 4.3 group scheduling regression Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-12 10:50 +0200
Re: [patch] sched: disable task group re-weighting on the desktop paul.szabo@sydney.edu.au - 2015-10-10 22:20 +0200
Re: [patch] sched: disable task group re-weighting on the desktop Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-11 04:40 +0200
Re: [patch] sched: disable task group re-weighting on the desktop paul.szabo@sydney.edu.au - 2015-10-11 11:30 +0200
Re: [patch] sched: disable task group re-weighting on the desktop Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-11 15:00 +0200
Re: [patch] sched: disable task group re-weighting on the desktop paul.szabo@sydney.edu.au - 2015-10-11 21:50 +0200
Re: [patch] sched: disable task group re-weighting on the desktop Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-12 04:00 +0200
Re: CFS scheduler unfairly prefers pinned tasks Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-08 16:30 +0200
Re: CFS scheduler unfairly prefers pinned tasks paul.szabo@sydney.edu.au - 2015-10-09 00:00 +0200
Re: CFS scheduler unfairly prefers pinned tasks Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-09 04:00 +0200
Re: CFS scheduler unfairly prefers pinned tasks Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-10-09 04:50 +0200
Re: CFS scheduler unfairly prefers pinned tasks paul.szabo@sydney.edu.au - 2015-10-11 11:50 +0200
Re: CFS scheduler unfairly prefers pinned tasks Wanpeng Li <wanpeng.li@hotmail.com> - 2015-10-10 06:10 +0200
Re: CFS scheduler unfairly prefers pinned tasks Wanpeng Li <wanpeng.li@hotmail.com> - 2015-10-10 10:00 +0200
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