From: Viresh Kumar <viresh.kumar@linaro.org>
To: Stratos Karafotis <stratosk@semaphore.gr>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [Resend][PATCH] cpufreq: conservative: Decrease frequency faster when the timer deferred
Date: Tue, 8 Nov 2016 09:34:29 +0530 [thread overview]
Message-ID: <20161108040429.GI21030@vireshk-i7> (raw)
In-Reply-To: <8acc17f0-d88f-19f6-f7a3-4c66cd65ab96@semaphore.gr>
On 07-11-16, 19:27, Stratos Karafotis wrote:
> Yes, it could be done only when we decrease frequency. But I thought that maybe
> this is against conservative governor principle.
>
> I initially observed this issue on a Snapdragon 808 using conservative on the
> big cluster (A57). The CPU seemed to remain in high frequencies for
> long time (even 10 seconds) before it returns to min.
>
> So, most probably the load after the deferred period is completely unrelated to
> the previous one. If we apply this heuristic only when the frequency will be
> decreased (and having in mind that we copy the load value from the previous
> period), IMHO I'm afraid that the conservative will be still more aggressive even
> from ondemand governor.
The deferred period here is actually the time for which the CPU was idle and not
doing anything.
And I am not sure why we should be worrying about increasing the frequency steps
for the period for which the CPU was idle.
--
viresh
next prev parent reply other threads:[~2016-11-08 4:04 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-06 9:19 [Resend][PATCH] cpufreq: conservative: Decrease frequency faster when the timer deferred Stratos Karafotis
2016-11-07 6:12 ` Viresh Kumar
2016-11-07 17:27 ` Stratos Karafotis
2016-11-08 4:04 ` Viresh Kumar [this message]
[not found] <076fb177-9cb3-4534-aadb-ebc2190d0751@email.android.com>
2016-11-08 8:32 ` Viresh Kumar
2016-11-08 19:25 ` Stratos Karafotis
2016-11-09 5:55 ` Viresh Kumar
2016-11-09 18:27 ` Stratos Karafotis
2016-11-10 0:13 ` Rafael J. Wysocki
2016-11-10 15:48 ` Stratos Karafotis
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