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From: Peter Zijlstra <peterz@infradead.org>
To: Joseph Salisbury <joseph.salisbury@canonical.com>
Cc: torvalds@linux-foundation.org, efault@gmx.de, tglx@linutronix.de,
	LKML <linux-kernel@vger.kernel.org>,
	mingo@kernel.org, Vincent Guittot <vincent.guittot@linaro.org>
Subject: Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes
Date: Sat, 8 Oct 2016 10:00:19 +0200	[thread overview]
Message-ID: <20161008080019.GE3142@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <57F7F9AF.2010609@canonical.com>

On Fri, Oct 07, 2016 at 03:38:23PM -0400, Joseph Salisbury wrote:
> Hello Peter,
> 
> A kernel bug report was opened against Ubuntu [0].  After a kernel
> bisect, it was found that reverting the following commit resolved this bug:
> 
> commit 3d30544f02120b884bba2a9466c87dba980e3be5
> Author: Peter Zijlstra <peterz@infradead.org>
> Date:   Tue Jun 21 14:27:50 2016 +0200
> 
>     sched/fair: Apply more PELT fixes

That commit doesn't revert cleanly, did you take out more?

> The regression was introduced as of v4.8-rc1.  The bug can be reproduced
> on an X1 Carbon with the following:
> stress -c $your_total_cpu_cores
> 
> I was hoping to get your feedback, since you are the patch author.  Do
> you think gathering any additional data will help diagnose this issue,
> or would it be best to submit a revert request? 

I'll try and have a look asap, but I'm traveling next week so it might a
tad slower than normal.

If you could provide a /proc/sched_debug dump while the thing is running
that'd might be useful.

Thanks!

  parent reply	other threads:[~2016-10-08  8:00 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-07 19:38 [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Joseph Salisbury
2016-10-07 19:57 ` Linus Torvalds
2016-10-07 20:22   ` Joseph Salisbury
2016-10-07 20:37     ` Linus Torvalds
2016-10-08  8:00 ` Peter Zijlstra [this message]
2016-10-08  8:39   ` Ingo Molnar
2016-10-08 11:37     ` Vincent Guittot
2016-10-08 11:49       ` Mike Galbraith
2016-10-12 12:20         ` Vincent Guittot
2016-10-12 15:35           ` Joseph Salisbury
2016-10-12 16:21           ` Joseph Salisbury
2016-10-13 10:58             ` Vincent Guittot
2016-10-13 15:52               ` Joseph Salisbury
2016-10-13 16:48                 ` Vincent Guittot
2016-10-13 18:49                   ` Dietmar Eggemann
2016-10-13 21:34                     ` Vincent Guittot
2016-10-14  8:24                       ` Vincent Guittot
2016-10-14 13:10                         ` Dietmar Eggemann
2016-10-14 15:18                           ` Vincent Guittot
2016-10-14 16:04                             ` Joseph Salisbury
2016-10-17  9:09                               ` Vincent Guittot
2016-10-17 11:49                                 ` Dietmar Eggemann
2016-10-17 13:19                                   ` Peter Zijlstra
2016-10-17 13:54                                     ` Vincent Guittot
2016-10-17 22:52                                       ` Dietmar Eggemann
2016-10-18  8:43                                         ` Vincent Guittot
2016-10-18  9:07                                         ` Peter Zijlstra
2016-10-18  9:45                                           ` Vincent Guittot
2016-10-18 10:34                                             ` Peter Zijlstra
2016-10-18 11:56                                               ` Vincent Guittot
2016-10-18 21:58                                                 ` Joonwoo Park
2016-10-19  6:42                                                   ` Vincent Guittot
2016-10-19  9:46                                                 ` Dietmar Eggemann
2016-10-19 11:25                                                   ` Vincent Guittot
2016-10-19 15:33                                                     ` Dietmar Eggemann
2016-10-19 17:33                                                       ` Joonwoo Park
2016-10-19 17:50                                                       ` Vincent Guittot
2016-10-19 11:33                                                 ` Peter Zijlstra
2016-10-19 11:50                                                   ` Vincent Guittot
2016-10-19 13:30                                                 ` Morten Rasmussen
2016-10-19 17:41                                                   ` Vincent Guittot
2016-10-20  7:56                                                     ` Morten Rasmussen
2016-10-19 14:49                                                 ` Joseph Salisbury
2016-10-19 14:53                                                   ` Vincent Guittot
2016-10-18 11:15                                           ` Dietmar Eggemann
2016-10-18 12:07                                             ` Peter Zijlstra

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