Re: [patch] sched: fix broken smt/mc optimizations with CFS

From: Ingo Molnar
Date: Tue Aug 28 2007 - 23:42:37 EST



* Siddha, Suresh B <suresh.b.siddha@xxxxxxxxx> wrote:

> On Mon, Aug 27, 2007 at 12:31:03PM -0700, Siddha, Suresh B wrote:
> > Essentially I observed that nice 0 tasks still endup on two cores of same
> > package, with out getting spread out to two different packages. This behavior
> > is same with out this fix and this fix doesn't help in any way.
>
> Ingo, Appended patch seems to fix the issue and as far as I can test,
> seems ok to me.

thanks! I've queued your fix up for .23 merge. I've done a quick test
and it indeed seems to work well.

> This is a quick fix for .23. Peter Williams and myself plan to look at
> code cleanups in this area (HT/MC optimizations) post .23
>
> BTW, with this fix, do you want to retain the current FUZZ value?

what value would you suggest? I was thinking about using
busiest_rq->curr->load.weight instead, to always keep rotating tasks.

Ingo
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