Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes

From	Joseph Salisbury <joseph.salisbury@canonical.com>
Newsgroups	linux.kernel
Subject	Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes
Date	2016-10-12 18:30 +0200
Message-ID	<sruzM-6Ti-7@gated-at.bofh.it> (permalink)
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On 10/12/2016 08:20 AM, Vincent Guittot wrote:
> On 8 October 2016 at 13:49, Mike Galbraith <efault@gmx.de> wrote:
>> On Sat, 2016-10-08 at 13:37 +0200, Vincent Guittot wrote:
>>> On 8 October 2016 at 10:39, Ingo Molnar <mingo@kernel.org> wrote:
>>>> * Peter Zijlstra <peterz@infradead.org> wrote:
>>>>
>>>>> 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
>>> This patch only speeds up the update of task group load in order to
>>> reflect the new load balance but It should not change the final value
>>> and as a result the final behavior. I will try to reproduce it in my
>>> target later today
>> FWIW, I tried and failed w/wo autogroup on 4.8 and master.
> Me too
>
> Is it possible to get some dump of  /proc/sched_debug while the problem occurs ?
>
> Vincent
>
>>         -Mike

The output from /proc/shed_debug can be seen here:
http://paste.ubuntu.com/23312351/

Ingo, the latest scheduler bits also still exhibit the bug:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git

Thread

[v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Joseph Salisbury <joseph.salisbury@canonical.com> - 2016-10-07 21:40 +0200
  Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-07 22:00 +0200
    Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Joseph Salisbury <joseph.salisbury@canonical.com> - 2016-10-07 22:30 +0200
      Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-07 22:40 +0200
  Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Peter Zijlstra <peterz@infradead.org> - 2016-10-08 10:10 +0200
    Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Ingo Molnar <mingo@kernel.org> - 2016-10-08 10:50 +0200
      Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-08 13:40 +0200
        Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Mike Galbraith <efault@gmx.de> - 2016-10-08 14:00 +0200
          Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-12 14:30 +0200
            Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Joseph Salisbury <joseph.salisbury@canonical.com> - 2016-10-12 17:40 +0200
            Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Joseph Salisbury <joseph.salisbury@canonical.com> - 2016-10-12 18:30 +0200
              Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-13 13:10 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Joseph Salisbury <joseph.salisbury@canonical.com> - 2016-10-13 18:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-13 19:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Dietmar Eggemann <dietmar.eggemann@arm.com> - 2016-10-13 21:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-13 23:40 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-14 10:30 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Dietmar Eggemann <dietmar.eggemann@arm.com> - 2016-10-14 15:20 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-14 17:20 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Joseph Salisbury <joseph.salisbury@canonical.com> - 2016-10-14 18:10 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-17 11:20 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Dietmar Eggemann <dietmar.eggemann@arm.com> - 2016-10-17 14:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Peter Zijlstra <peterz@infradead.org> - 2016-10-17 15:30 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-17 16:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Dietmar Eggemann <dietmar.eggemann@arm.com> - 2016-10-18 01:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-18 10:50 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Peter Zijlstra <peterz@infradead.org> - 2016-10-18 11:10 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-18 11:50 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Peter Zijlstra <peterz@infradead.org> - 2016-10-18 12:40 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-18 14:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Joonwoo Park <joonwoop@codeaurora.org> - 2016-10-19 00:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-19 08:50 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-19 16:50 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Joseph Salisbury <joseph.salisbury@canonical.com> - 2016-10-19 17:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-19 17:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Dietmar Eggemann <dietmar.eggemann@arm.com> - 2016-10-19 17:40 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Joonwoo Park <joonwoop@codeaurora.org> - 2016-10-19 19:40 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-19 20:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-19 17:50 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Dietmar Eggemann <dietmar.eggemann@arm.com> - 2016-10-19 17:50 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Peter Zijlstra <peterz@infradead.org> - 2016-10-19 18:20 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Morten Rasmussen <morten.rasmussen@arm.com> - 2016-10-19 18:40 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Vincent Guittot <vincent.guittot@linaro.org> - 2016-10-19 19:50 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Morten Rasmussen <morten.rasmussen@arm.com> - 2016-10-20 10:00 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Dietmar Eggemann <dietmar.eggemann@arm.com> - 2016-10-18 13:20 +0200
                Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes Peter Zijlstra <peterz@infradead.org> - 2016-10-18 14:10 +0200

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