From: Mike Galbraith <mgalbraith@suse.de>
To: Peter Zijlstra <peterz@infradead.org>,
mingo@kernel.org, linux-kernel@vger.kernel.org
Cc: Pavan Kondeti <pkondeti@codeaurora.org>,
Ben Segall <bsegall@google.com>,
Matt Fleming <matt@codeblueprint.co.uk>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Paul Turner <pjt@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
byungchul.park@lge.com, Andrew Hunter <ahh@google.com>
Subject: Re: [PATCH 2/3] sched,fair: Fix local starvation
Date: Sat, 21 May 2016 16:04:48 +0200 [thread overview]
Message-ID: <1463839488.24578.45.camel@suse.de> (raw)
In-Reply-To: <20160510174613.902178264@infradead.org>
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
next prev parent reply other threads:[~2016-05-21 14:04 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-10 17:43 [PATCH 0/3] sched: Fix wakeup preemption regression Peter Zijlstra
2016-05-10 17:43 ` [PATCH 1/3] sched,fair: Move record_wakee() Peter Zijlstra
2016-05-12 10:27 ` Matt Fleming
2016-05-12 10:31 ` Peter Zijlstra
2016-05-10 17:43 ` [PATCH 2/3] sched,fair: Fix local starvation Peter Zijlstra
2016-05-10 20:21 ` Ingo Molnar
2016-05-10 22:23 ` Peter Zijlstra
2016-05-20 21:24 ` Matt Fleming
2016-05-21 14:04 ` Mike Galbraith [this message]
2016-05-21 19:00 ` Mike Galbraith
2016-05-22 7:00 ` [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Mike Galbraith
2016-05-22 9:36 ` Peter Zijlstra
2016-05-22 9:52 ` Mike Galbraith
2016-05-22 10:33 ` Peter Zijlstra
2016-05-23 9:19 ` Peter Zijlstra
2016-05-23 9:40 ` Mike Galbraith
2016-05-23 10:13 ` Wanpeng Li
2016-05-23 10:26 ` Mike Galbraith
2016-05-23 12:28 ` Peter Zijlstra
2016-05-25 7:12 ` [tip:sched/urgent] sched/core: Fix remote wakeups tip-bot for Peter Zijlstra
2016-05-22 6:50 ` [PATCH 2/3] sched,fair: Fix local starvation Wanpeng Li
2016-05-22 7:15 ` Mike Galbraith
2016-05-22 7:27 ` Wanpeng Li
2016-05-22 7:32 ` Mike Galbraith
2016-05-22 7:42 ` Wanpeng Li
2016-05-22 8:04 ` Mike Galbraith
2016-05-22 8:24 ` Wanpeng Li
2016-05-22 8:39 ` Mike Galbraith
2016-05-22 8:50 ` Wanpeng Li
2016-05-10 17:43 ` [PATCH 3/3] sched: Kill sched_class::task_waking Peter Zijlstra
2016-05-11 5:55 ` [PATCH 0/3] sched: Fix wakeup preemption regression Mike Galbraith
2016-05-12 9:56 ` Pavan Kondeti
2016-05-12 10:52 ` Matt Fleming
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