From: Matthew Garrett <mjg@redhat.com>
To: Corrado Zoccolo <czoccolo@gmail.com>
Cc: Dave Jones <davej@redhat.com>,
linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org
Subject: Re: [PATCH] cpufreq: ondemand: Introduces stepped frequency increase
Date: Wed, 8 Jul 2009 17:10:52 +0100 [thread overview]
Message-ID: <20090708161052.GA20951@srcf.ucam.org> (raw)
In-Reply-To: <200907081556.34682.czoccolo@gmail.com>
On Wed, Jul 08, 2009 at 03:56:33PM +0200, Corrado Zoccolo wrote:
> The patch introduces a new sysfs tunable cpufreq/ondemand/freq_step,
> as found in conservative governor, to chose the frequency increase step,
> expressed as percentage (default = 100 is previous behaviour).
>
> This allows fine tuning powersaving on mobile CPUs, since smaller steps will allow to:
> * absorb punctual load spikes
> * stabilize at the needed frequency, without passing for more power consuming states, and
Is this a measured powersaving? The ondemand model is based on the
assumption that the idle state is disproportionately lower in power than
any running state, and therefore it's more sensible to run flat out for
short periods of time than run at half speed for longer. Is this
inherently flawed, or is it an artifact of differences in your processor
design?
--
Matthew Garrett | mjg59@srcf.ucam.org
next prev parent reply other threads:[~2009-07-08 16:11 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-08 13:56 Corrado Zoccolo
2009-07-08 14:18 ` Michael S. Zick
2009-07-08 17:45 ` Corrado Zoccolo
2009-07-08 16:10 ` Matthew Garrett [this message]
2009-07-08 16:33 ` Pallipadi, Venkatesh
2009-07-08 18:05 ` Corrado Zoccolo
2009-07-08 17:41 ` Corrado Zoccolo
2009-07-08 17:47 ` Matthew Garrett
2009-07-14 14:37 ` Corrado Zoccolo
2009-07-09 23:34 ` Pavel Machek
2009-07-14 14:44 ` Corrado Zoccolo
2009-07-14 14:59 ` Matthew Garrett
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