linux-kernel - Re: [PATCH 2/2] cpufreq: don't call cpufreq_update

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Date:	Mon, 17 Feb 2014 23:22:07 +0100
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Viresh Kumar <viresh.kumar@...aro.org>
Cc:	Lists linaro-kernel <linaro-kernel@...ts.linaro.org>,
	"cpufreq@...r.kernel.org" <cpufreq@...r.kernel.org>,
	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Pierre Ossman <pierre-list@...man.eu>
Subject: Re: [PATCH 2/2] cpufreq: don't call cpufreq_update_policy() on CPU addition

On Monday, February 17, 2014 10:45:41 AM Viresh Kumar wrote:
> On 17 February 2014 05:51, Rafael J. Wysocki <rjw@...ysocki.net> wrote:
> > On Friday, February 14, 2014 04:30:41 PM Viresh Kumar wrote:
> >> cpufreq_update_policy() is called from two places currently. From a workqueue
> >> handled queued from cpufreq_bp_resume() for boot CPU and from
> >> cpufreq_cpu_callback() whenever a CPU is added.
> >>
> >> The first one makes sure that boot CPU is running on the frequency present in
> >> policy->cpu. But we don't really need a call from cpufreq_cpu_callback(),
> >> because we always call cpufreq_driver->init() (which will set policy->cur
> >> correctly) whenever first CPU of any policy is added back. And so every policy
> >> structure is guaranteed to have the right frequency in policy->cur.
> >
> > That sounds good, but doing the extra cpufreq_update_policy() shouldn't actually
> > hurt, should it?
> 
> Yeah, it shouldn't hurt badly..
> 
> > So, that would be a cleanup rather than a fix, right?
> 
> Hmm, yeah..

I've queued this up for 3.15, then.  Thanks!

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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