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

From: Mike Galbraith
Date: Sat Oct 08 2016 - 07:50:01 EST


On Sat, 2016-10-08 at 13:37 +0200, Vincent Guittot wrote:
> On 8 October 2016 at 10:39, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> >
> > * Peter Zijlstra <peterz@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
> > > > 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