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From: Steve Muckle <steve.muckle@linaro.org>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Michael Turquette <mturquette@baylibre.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Juri Lelli <Juri.Lelli@arm.com>,
	Patrick Bellasi <patrick.bellasi@arm.com>,
	Morten Rasmussen <morten.rasmussen@arm.com>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
	Peter Zijlstra <peterz@infradead.org>
Subject: Re: sched-freq locking
Date: Wed, 20 Jan 2016 17:39:14 -0800	[thread overview]
Message-ID: <56A036C2.4090403@linaro.org> (raw)
In-Reply-To: <2058083.HonoCMD469@vostro.rjw.lan>

On 01/20/2016 05:22 PM, Rafael J. Wysocki wrote:
> One comment here (which may be a bit off in which case please ignore it).
> 
> You seem to be thinking that sched-freq needs to be a cpufreq governor
> and thus be handled in the same way as ondemand, for example.

That's true, I hadn't really given much thought to the alternative you
mention below.

> 
> However, this doesn't have to be the case in principle.  For example,
> if we have a special driver callback specifically to work with sched-freq,
> it may just use that callback and bypass (almost) all of the usual
> cpufreq mechanics.  This way you may avoid worrying about the governor
> locking and related ugliness entirely.

That sounds good but I'm worried about other consequences of taking
cpufreq out of the loop. For example wouldn't we need a new way for
something like thermal to set frequency limits?

thanks,
steve

  reply	other threads:[~2016-01-21  1:39 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <56984C30.8040402@linaro.org>
     [not found] ` <20160115104051.GP18603@e106622-lin>
     [not found]   ` <569D568D.5000500@linaro.org>
     [not found]     ` <CAEG3pNDoDHpgO7WdC8n7C8Ri+KNKZqOi9rKHMkTV0c5dkyevOw@mail.gmail.com>
     [not found]       ` <CAKfTPtCYUWBm_=GQ-NLLZ01xJqG+83vy4uapxRLjqMx_61HSew@mail.gmail.com>
     [not found]         ` <569E90CF.9050503@linaro.org>
     [not found]           ` <CAEG3pND5kHqJhrvwVjsnCnfT-nSrV8SrUaNk2p=ZfEx0MmmB=A@mail.gmail.com>
     [not found]             ` <569EB225.4040707@linaro.org>
     [not found]               ` <CAEG3pNBgpsdX8Lk7_3nHd31_bsq2sLB_f+=4_xiFFbiAWiKsxg@mail.gmail.com>
2016-01-20  1:24                 ` sched-freq locking Steve Muckle
2016-01-20 12:18                   ` Juri Lelli
2016-01-20 14:50                     ` Steve Muckle
2016-01-20 15:58                       ` Juri Lelli
2016-01-20 16:39                         ` Punit Agrawal
2016-01-20 16:46                         ` Punit Agrawal
2016-01-20 20:46                         ` Steve Muckle
2016-01-21  9:45                           ` Juri Lelli
2016-01-21 19:29                             ` Steve Muckle
2016-01-21  1:22                   ` Rafael J. Wysocki
2016-01-21  1:39                     ` Steve Muckle [this message]
2016-01-21  1:46                       ` Rafael J. Wysocki
2016-01-21 10:49                         ` Juri Lelli
2016-01-22  1:21                           ` Rafael J. Wysocki
2016-01-27  1:54                             ` Steve Muckle
2016-01-27  8:03                               ` Rafael J. Wysocki

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