Re: [PATCH] proc: Get/set timer slack through /proc

[Arjan van de Ven]

On Thu, 31 Dec 2009 13:01:49 -0800
"Smith, GeoffX" <geoffx.smith@xxxxxxxxx> wrote:

> Subject: Get/set timer_slack_ns through /proc
> 
> This patch makes the timer_slack_ns parameter accessible through
> the /proc system.
> 
> On 9/1/2008, arjan@xxxxxxxxxxxxxxx submitted a patch to allow a
> process to set the timer slack value as part of the range timers
> feature.  Further, he noted that "Applications and admins can
> override this [the timer slack value] via the prctl()."
> 
> We have found this feature useful in attempting to reduce system
> wakeups caused by timer interrupts.  But we have also found that
> while applications can set their own timer slack value, there is no
> provision for setting the timer slack for another process -- prctl()
> only operates on the current process.  
> 

this statement is incorrect btw;
timerslack is explicitly inherited over exec, so you can have (and we
do have) a utility similar to the nice program, that launches an
application with a specific timer slack.


-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org
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