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Subject: Re: CFS flat runqueue proposal fixes/update
To:     Rik van Riel <riel@surriel.com>,
        Peter Zijlstra <peterz@infradead.org>
Cc:     Paul Turner <pjt@google.com>,
        "vincent.guittot" <vincent.guittot@linaro.org>, kernel-team@fb.com,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "dietmar.eggeman" <dietmar.eggeman@arm.com>
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From:   Dietmar Eggemann <dietmar.eggemann@arm.com>
Message-ID: <7b6349fc-c4c1-9c32-6b8f-0a9b3d7fa93c@arm.com>
Date:   Fri, 21 Aug 2020 19:53:27 +0200
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On 20.08.20 22:39, Rik van Riel wrote:
> On Thu, 2020-08-20 at 16:56 +0200, Dietmar Eggemann wrote:

[...]

> The issue happens with a flat runqueue, when t1 goes
> to sleep, but t2 and t3 continue running.
> 
> We need to make sure the vruntime for t2 has not been
> advanced so far into the future that cgroup A is unable
> to get its fair share of CPU wihle t1 is sleeping.

Ah, these problems are related to the 'CFS flat runqueue' patch-set!
Misunderstanding om my side.

I somehow assumed that you wanted to say that these problems exist in
current mainline and could be solved with the patch-set plus some extra
functionality on top.