Re: 2.6.15-ck1

[Arjan van de Ven <arjan@infradead.org>]

On Wed, 2006-01-04 at 14:57 -0500, Dave Jones wrote:
> On Wed, Jan 04, 2006 at 02:05:54PM -0500, Dave Jones wrote:
>  > On Wed, Jan 04, 2006 at 12:00:00PM +1100, Con Kolivas wrote:
>  >  >  +2.6.15-dynticks-060101.patch
>  >  >  +dynticks-disable_smp_config.patch
>  >  > Latest version of the dynticks patch. This is proving stable and effective on 
>  >  > virtually all uniprocessor machines and will benefit systems that desire 
>  >  > power savings. SMP kernels (even on UP machines) still misbehave so this 
>  >  > config option is not available by default for this stable kernel.
>  > 
>  > I've been curious for some time if this would actually show any measurable
>  > power savings. So I hooked up my laptop to a gizmo[1] that shows how much
>  > power is being sucked.
>  > 
>  > both before, and after, it shows my laptop when idle is pulling 21W.
>  > So either the savings here are <1W (My device can't measure more accurately
>  > than a single watt), or this isn't actually buying us anything at all, or
>  > something needs tuning.
> 
> Ah interesting. It needs to be totally idle for a period of time before
> anything starts to happen at all. After about a minute of doing nothing,
> it started to fluctuate once a second 20,21,19,20,19,20,18,21,19,20,22 etc..


sounds like we need some sort of profiler or benchmarker or at least a
tool that helps finding out which timers are regularly firing, with the
aim at either grouping them or trying to reduce their disturbance in
some form.


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