Message-ID: <1475927349.5573.1.camel@gmx.de>
Subject: Re: [v4.8-rc1 Regression] sched/fair: Apply more PELT fixes
From: Mike Galbraith <efault@gmx.de>
To: Vincent Guittot <vincent.guittot@linaro.org>,
        Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
        Joseph Salisbury <joseph.salisbury@canonical.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>
Date: Sat, 08 Oct 2016 13:49:09 +0200
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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.

	-Mike