LWN.net Logo

Re: [RFC v1] Tunable sched_mc_power_savings=n

From:  Peter Zijlstra <peterz-AT-infradead.org>
To:  Andi Kleen <andi-AT-firstfloor.org>
Subject:  Re: [RFC v1] Tunable sched_mc_power_savings=n
Date:  Thu, 26 Jun 2008 23:43:04 +0200
Message-ID:  <1214516584.12265.10.camel@twins.programming.kicks-ass.net>
Cc:  dipankar-AT-in.ibm.com, balbir-AT-linux.vnet.ibm.com, Linux Kernel <linux-kernel-AT-vger.kernel.org>, Suresh B Siddha <suresh.b.siddha-AT-intel.com>, Venkatesh Pallipadi <venkatesh.pallipadi-AT-intel.com>, Ingo Molnar <mingo-AT-elte.hu>, Peter Zijlstra <a.p.zijlstra-AT-chello.nl>, Vatsa <vatsa-AT-linux.vnet.ibm.com>, Gautham R Shenoy <ego-AT-in.ibm.com>
Archive-link:  Article, Thread

On Thu, 2008-06-26 at 23:37 +0200, Andi Kleen wrote:
> Dipankar Sarma wrote:
> 
> > Some workload managers already do that - they provision cpu and memory
> > resources based on request rates and response times. Such software is
> > in a better position to make a decision whether they can live with
> > reduced performance due to power saving mode or not. The point I am
> > making is the the kernel doesn't have any notion of transactional
> > performance 
> 
> The kernel definitely knows about burstiness vs non burstiness at least
> (although it currently has no long term memory for that). Does it need
> more than that for this? Anyways if nice levels were used that is not
> even needed, because it's ok to run niced processes slower.
> 
> And your workload manager could just nice processes. It should probably
> do that anyways to tell ondemand you don't need full frequency.

Except that I want my nice 19 distcc processes to utilize as much cpu as
possible, but just not bother any other stuff I might be doing...





(Log in to post comments)

Copyright © 2008, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds