Re: [PATCH] cpufreq: ondemand: Introduces stepped frequencyincrease

From: Matthew Garrett
Date: Wed Jul 08 2009 - 12:11:17 EST


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@xxxxxxxxxxxxx
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