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Subject: Re: [PATCH v5 1/3] sched: Stop nohz stats when decayed
From:   Valentin Schneider <valentin.schneider@arm.com>
To:     Vincent Guittot <vincent.guittot@linaro.org>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Morten Rasmussen <morten.rasmussen@foss.arm.com>,
        Brendan Jackman <brendan.jackman@arm.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>
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Message-ID: <f557c2fc-7175-33c1-16c3-839da6bf4702@arm.com>
Date:   Wed, 21 Feb 2018 13:48:31 +0000
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On 02/21/2018 01:13 PM, Valentin Schneider wrote:
> On 02/16/2018 01:44 PM, Vincent Guittot wrote:
>> On 16 February 2018 at 13:13, Valentin Schneider
>> <valentin.schneider@arm.com> wrote:
>>> On 02/14/2018 03:26 PM, Vincent Guittot wrote:
> BTW, with the current set on Peter's sched/testing, update_nohz_stats()
> is called here, which doesn't do the update if !rq->has_blocked_load
> (Although that check is done without lock/barrier, so maybe we could not see
> a CPU that just went idle ?)

Ignore that, that's another case of me being overly paranoid after reading
too much of Documentation/memory-barriers.txt