linux-kernel - Re: [PATCH 1/6] cpufreq: schedutil: reset sg

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Message-ID: <1642681.8y9FrPCKVW@aspire.rjw.lan>
Date:   Wed, 29 Mar 2017 00:18:05 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Patrick Bellasi <patrick.bellasi@....com>
Cc:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        John Stultz <john.stultz@...aro.org>,
        Juri Lelli <juri.lelli@....com>, Todd Kjos <tkjos@...roid.com>,
        Tim Murray <timmurray@...gle.com>,
        Andres Oportus <andresoportus@...gle.com>,
        Joel Fernandes <joelaf@...gle.com>,
        Morten Rasmussen <morten.rasmussen@....com>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Chris Redpath <chris.redpath@....com>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH 1/6] cpufreq: schedutil: reset sg_cpus's flags at IDLE enter

On Thursday, March 02, 2017 03:45:02 PM Patrick Bellasi wrote:
> Currently, sg_cpu's flags are set to the value defined by the last call of
> the cpufreq_update_util()/cpufreq_update_this_cpu(); for RT/DL classes
> this corresponds to the SCHED_CPUFREQ_{RT/DL} flags always being set.
> 
> When multiple CPU shares the same frequency domain it might happen that a
> CPU which executed an RT task, right before entering IDLE, has one of the
> SCHED_CPUFREQ_RT_DL flags set, permanently, until it exits IDLE.

But if it is idle, it won't be taken into account by sugov_next_freq_shared(), will it?

Thanks,
Rafael