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Date:   Fri, 20 Nov 2020 09:27:24 +0000
From:   Quentin Perret <qperret@google.com>
To:     Viresh Kumar <viresh.kumar@linaro.org>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Ingo Molnar <mingo@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Morten Rasmussen <morten.rasmussen@arm.com>,
        dietmar.eggemann@arm.com, patrick.bellasi@matbug.net,
        lenb@kernel.org, linux-kernel@vger.kernel.org,
        valentin.schneider@arm.com, ionela.voinescu@arm.com
Subject: Re: [RFC] Documentation/scheduler/schedutil.txt
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On Friday 20 Nov 2020 at 14:49:04 (+0530), Viresh Kumar wrote:
>     This is unlikely to be an issue on systems where cpufreq policies are
>     shared between multiple CPUs, because in those cases the policy
>     utilization is computed as the maximum of the CPU utilization values
>     over the whole policy and if that turns out to be low, reducing the
>     frequency for the policy most likely is a good idea anyway.

Hmm, I'm not sure I agree with this actually. We may be migrating the
task to a different policy altogether. And even if we migrate to another
CPU in the current policy, the task util_avg may be small just because
it was packed with other tasks on a rq, which means it may not increase
the util of the destination rq by much.

ISTR Douglas' EM-based schedutil boosting series was addressing that at
some point, I'll go have a look back at that discussion...