Messages in this thread | | | Date | Tue, 22 Dec 2009 20:57:43 +0100 | From | Arjan van de Ven <> | Subject | Re: RFC: A proposal for power capping through forced idle in the Linux Kernel |
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On Tue, 22 Dec 2009 20:48:24 +0100 Peter Zijlstra <peterz@infradead.org> wrote:
> On Mon, 2009-12-14 at 16:19 -0800, Arjan van de Ven wrote: > > > I like the general idea, I have one request (that I didn't see > > quite in your explanation): Please make sure that all cpus in the > > system do their idle injection at the same time, so that memory can > > go into power saving mode as well during this time etc etc... > > And then you're going to ask that it scales too, right? :-) > > Gang-scheduling is inherently non scalable, be it for idle time or > not.
well... there's many ways to do this... one option is to agree, ahead of time, which jiffies values you're going to do the idle thing on. Say every 100 jiffies where jiffies % 100 is 0....
then the scalability thing isn't a big deal.. and you still do it all at the same time. Or at least "enough" at the same time for it to not matter
-- 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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