linux-kernel - Re: [PATCH 2/2] cpufreq: ondemand: Eliminate the deadband effect

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Message-ID: <20140711165710.GA18033@amd.pavel.ucw.cz>
Date:	Fri, 11 Jul 2014 18:57:10 +0200
From:	Pavel Machek <pavel@....cz>
To:	Stratos Karafotis <stratosk@...aphore.gr>
Cc:	rjw@...ysocki.net, viresh.kumar@...aro.org,
	linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] cpufreq: ondemand: Eliminate the deadband effect

Hi!

> Tested on Intel i7-3770 CPU @ 3.40GHz and on ARM quad core 1500MHz Krait
> (Android smartphone).
> Benchmarks on Intel i7 shows a performance improvement on low and medium
> work loads with lower power consumption. Specifics:
> 
> Phoronix Linux Kernel Compilation 3.1:
> Time: -0.40%, energy: -0.07%
> Phoronix Apache:
> Time: -4.98%, energy: -2.35%
> Phoronix FFMPEG:
> Time: -6.29%, energy: -4.02%

Hmm. Intel i7 should be race-to-idle machine. So basically rule like
if (load > 0) go to max frequency else go to lowest frequency would do
the right thing in your test, right?

So... should we do that, or do we need better benchmark?
									Pavel

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