linux-kernel - Re: [PATCH v3 0/6] cpufreq: schedutil: fixes for flags updates

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Date:   Thu, 8 Feb 2018 17:14:58 +0100
From:   Claudio Scordino <claudio@...dence.eu.com>
To:     Patrick Bellasi <patrick.bellasi@....com>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        Ingo Molnar <mingo@...hat.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Morten Rasmussen <morten.rasmussen@....com>,
        Juri Lelli <juri.lelli@...hat.com>,
        Todd Kjos <tkjos@...roid.com>,
        Joel Fernandes <joelaf@...gle.com>
Subject: Re: [PATCH v3 0/6] cpufreq: schedutil: fixes for flags updates

Hi Patrick,

Il 06/02/2018 19:36, Patrick Bellasi ha scritto:
> On 06-Feb 19:14, Claudio Scordino wrote:
>> Hi Patrick,
> 
>>> At first glance, your proposal below makes to make sense.
>>>
>>> However, I'm wondering if we cannot get it working using
>>> rq->dl's provided information instead of flags?
>>
>> Yes, we can use the value of rq->dl to check if there has been an increase of the deadline utilization.
>> Even if schedutil might have been triggered by a different scheduling class, the effect should be almost the same.
>>
>> Below a potential patch. I've kept all frequency update decisions in a single point (i.e. sugov_should_update_freq).
>> Not yet tested (waiting for further comments).
> 
> I have a todo list entry to backport/test Peter's series on Android...
> will add this patch too. Thanks.

Please discard my latest patch, as the tests on Odroid have shown performance regressions
(likely due to sugov_next_freq_shared being called more often)

Never mind. I have already tested another (even simpler) patch.
Sending soon as a new thread on LKML.

Many thanks and best regards,

                 Claudio