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Date: Mon, 1 May 2017 16:52:23 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Tejun Heo <tj@kernel.org>, Ingo Molnar <mingo@redhat.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Mike Galbraith <efault@gmx.de>, Paul Turner <pjt@google.com>,
        Chris Mason <clm@fb.com>, kernel-team@fb.com
Subject: Re: [PATCH 1/2] sched/fair: Fix how load gets propagated from cfs_rq
 to its sched_entity
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On Mon, May 01, 2017 at 04:17:33PM +0200, Peter Zijlstra wrote:

> So this here does:
> 
>   ( tg->load_avg = \Sum cfs_rq->load_avg )
> 
>   load      = cfs_rq->load.weight
> 
>   tg_weight = tg->load_avg - cfs_rq->contrib + load
> 
> 
>            tg->shares * load
>   shares = -----------------
>                tg_weight
> 
> 
>                         cfs_rq->load_avg
>   avg_shares = shares * ----------------
>                               load
> 
> 	       tg->shares * cfs_rq->load_avg
>              = -----------------------------
>                       tg_weight
> 
> 
>   ( se->load.weight = shares )
> 
>   se->load_avg = min(shares, avg_shares);

I wonder though; do we really need the min() ? Can't we simply use
avg_shares all the time?