Re: [PATCH 0/3][RFC] Improve load balancing when tasks have largeweight differential

[Mike Galbraith]

On Wed, 2010-10-06 at 01:23 -0700, Nikhil Rao wrote:
> On Sun, Oct 3, 2010 at 8:08 PM, Mike Galbraith <efault@xxxxxx> wrote:
> > On Wed, 2010-09-29 at 12:32 -0700, Nikhil Rao wrote:
> >> The closest I have is a quad-core dual-socket machine (MC, CPU
> >> domains). And I'm having trouble reproducing it on that machine as
> >> well :-( I ran 5 soaker threads (one of them niced to -15) for a few
> >> hours and didn't see the problem. Can you please give me some trace
> >> data & schedstats to work with?
> >
> > Booting with isolcpus or offlining the excess should help.
> >
> 
> Sorry for the late reply. Booting with isolcpus did the trick, thanks.
> 
> ... and now to dig into why this is happening.

I was poking it (again) yesterday, and it's kind of annoying.  I can't
call this behavior black/white broken.  It's freeing up a cache for a
very high priority task, which is kinda nice, but SMP nice is costing
25% of my box's processor power in this case too.  Hrmph.

	-Mike

--
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/