Date: Wed, 12 Apr 2017 14:27:41 +0100
From: Patrick Bellasi <patrick.bellasi@arm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>, linux-kernel@vger.kernel.org,
        linux-pm@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Paul Turner <pjt@google.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        John Stultz <john.stultz@linaro.org>, Todd Kjos <tkjos@android.com>,
        Tim Murray <timmurray@google.com>,
        Andres Oportus <andresoportus@google.com>,
        Joel Fernandes <joelaf@google.com>, Juri Lelli <juri.lelli@arm.com>,
        Chris Redpath <chris.redpath@arm.com>,
        Morten Rasmussen <morten.rasmussen@arm.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>
Subject: Re: [RFC v3 0/5] Add capacity capping support to the CPU controller
Message-ID: <20170412132741.GK29455@e110439-lin>
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On 12-Apr 14:48, Peter Zijlstra wrote:
> On Tue, Apr 11, 2017 at 06:58:33PM +0100, Patrick Bellasi wrote:
> > >     illustrated per your above points in that it affects both, while in
> > >     fact it actually modifies another metric, namely util_avg.
> > 
> > I don't see it modifying in any direct way util_avg.
> 
> The point is that clamps called 'capacity' are applied to util. So while
> you don't modify util directly, you do modify the util signal (for one
> consumer).

Right, but this consumer (i.e. schedutil) it's already translating
the util_avg into a next_freq (which ultimately it's a capacity).

Thus, I don't see a big misfit in that code path to "filter" this
translation with a capacity clamp.

-- 
#include <best/regards.h>

Patrick Bellasi