linux-kernel - Re: [PATCH] cpufreq: ondemand: Change the calculation of target frequency

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Message-ID: <CAKohpokmn-Rf-1w2aQHMMMkMbJqxokWXm5ye3DNuc-yzzk=7pQ@mail.gmail.com>
Date:	Sat, 1 Jun 2013 20:26:47 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	Stratos Karafotis <stratosk@...aphore.gr>
Cc:	"Rafael J. Wysocki" <rjw@...k.pl>, linux-kernel@...r.kernel.org,
	cpufreq@...r.kernel.org, linux-pm@...r.kernel.org
Subject: Re: [PATCH] cpufreq: ondemand: Change the calculation of target frequency

On 31 May 2013 22:03, Stratos Karafotis <stratosk@...aphore.gr> wrote:
> On 05/31/2013 11:51 AM, Viresh Kumar wrote:
>> I believe you should have removed other users of getavg() in a separate
>> patch and also cc'd relevant people so that you can some review comments
>> from  them.
>
> I will split the patch in two. If it's OK, I will keep the removal of
> __cpufreq_driver_getavg in the original patch and move the clean up of
> APERF/MPERF support in a second patch. I will also cc relevant people.

Even removal of __cpufreq_driver_getavg() should be done in a separate
patch, so that it can be reverted easily if required later.

>> "Proportional to load" means C * load, so why is "policy->max / 100" *the* right C?
>
> I think, finally(?) I see your point. The right C should be "policy->cpuinfo.max_freq / 100".

Why are you changing it to cpuinfo.max_freq?? This is fixed once a driver is
initialized.. but user may request a lower max freq for a governor or policy.
Which is actually reflected in policy->max I believe.

Over that why keeping following check is useful anymore?

if (load_freq > od_tuners->up_threshold)
    goto max.

As, if load is over 95, then even policy->max * 95 / 100 will even give almost
the same freq.
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