linux-kernel - Re: [PATCH] cpufreq: schedutil: Always trace frequency if it does not change

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Message-ID: <20170322095615.GB12094@vireshk-i7>
Date:   Wed, 22 Mar 2017 15:26:15 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Linux PM <linux-pm@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Patrick Bellasi <patrick.bellasi@....com>,
        Vincent Guittot <vincent.guittot@...aro.org>
Subject: Re: [PATCH] cpufreq: schedutil: Always trace frequency if it does
 not change

On 22-03-17, 10:29, Peter Zijlstra wrote:
> On Wed, Mar 22, 2017 at 01:56:53AM +0100, Rafael J. Wysocki wrote:

> > However, the same problem may occur for a cpufreq driver that doesn't
> > support fast frequency switching and implements the ->target callback
> > (that is, it doesn't use frequency tables), but trace_cpu_frequency()
> > is not called if frequency updates are skipped in that case.
> 
> I'm having trouble parsing that; am I right in understanding this is the
> exact same scenario where only superfluous changes are omitted?

Yes. Just for a different driver type.

-- 
viresh