linux-kernel - Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable

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Message-ID: <20160315212047.GE6344@twins.programming.kicks-ass.net>
Date:	Tue, 15 Mar 2016 22:20:47 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Michael Turquette <mturquette@...libre.com>
Cc:	rjw@...ysocki.net, linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org, Juri.Lelli@....com,
	steve.muckle@...aro.org, morten.rasmussen@....com,
	dietmar.eggemann@....com, vincent.guittot@...aro.org,
	Michael Turquette <mturquette+renesas@...libre.com>
Subject: Re: [PATCH 4/8] cpufreq/schedutil: sysfs capacity margin tunable

On Sun, Mar 13, 2016 at 10:22:08PM -0700, Michael Turquette wrote:
> With the addition of the global cfs capacity margin helpers in patch,
> "sched/cpufreq: new cfs capacity margin helpers", we can now export
> sysfs tunables from the schedutil governor. This allows privileged users
> to tune the value more easily.
> 
> The margin value is global to cfs, not per-policy. As such schedutil
> does not store any state about the margin. Schedutil restores the margin
> value to its default value when exiting.

Yuck sysfs.. I would really rather we did not expose this per default.
And certainly not in this weird form.