Re: [PATCH 1/2] Customize sched domain via cpuset

From: Peter Zijlstra
Date: Tue Apr 01 2008 - 07:56:30 EST


On Tue, 2008-04-01 at 13:40 +0200, Andi Kleen wrote:
> Hidetoshi Seto <seto.hidetoshi@xxxxxxxxxxxxxx> writes:
>
> > Using cpuset, now we can partition the system into multiple sched domains.
> > Then, how about providing different characteristics for each domains?
>
> Did you actually see much improvement in any relevant workload
> from tweaking these parameters? If yes what did you change?
> And how much did it gain?
>
> Ideally the kernel should perform well without much tweaking
> out of the box, simply because most users won't tweak. Adding a
> lot of such parameters would imply giving up on good defaults which
> is not a good thing.

>From what I understand they need very aggressive idle balancing; much
more so than what is normally healty.

I can see how something like that can be useful when you have a lot of
very short running tasks. These could pile up on a few cpus and leave
others idle.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/