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Date: Mon, 26 Sep 2016 16:53:54 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Yuyang Du <yuyang.du@intel.com>,
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        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Paul Turner <pjt@google.com>, Benjamin Segall <bsegall@google.com>
Subject: Re: [PATCH 7/7 v3] sched: fix wrong utilization accounting when
 switching to fair class
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On Thu, Sep 22, 2016 at 02:25:18PM +0200, Peter Zijlstra wrote:
> On Tue, Sep 20, 2016 at 03:06:04PM +0200, Vincent Guittot wrote:
> > > Also, even it things magically worked out, its still very icky to mix
> > > the normalized vruntime into things.
> > 
> > I agree
> 
> In any case, I pushed out a bunch of patches to:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/tmp
> 
> they appear to be able to build a kernel, but that's not much testing.

Hurmph, its buggered for cgroups. When we get the newidle lockbreak
between dequeue and put_prev_task, the load-balance pull can add a task
to the 'current' cgroup.

Which suggests we cannot do that enqueue_entity() optimization, unless
we fix that dequeue+put atomicy muck.