From: Mike Galbraith <efault@gmx.de>
To: Nikhil Rao <ncrao@google.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>,
Venkatesh Pallipadi <venki@google.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/3][RFC] Improve load balancing when tasks have large weight differential
Date: Fri, 08 Oct 2010 09:22:23 +0200 [thread overview]
Message-ID: <1286522543.8189.13.camel@marge.simson.net> (raw)
In-Reply-To: <AANLkTinf7fj5A4DnQOWdj8QeMhf4exPGgpMUdTGA9mTC@mail.gmail.com>
On Wed, 2010-10-06 at 01:23 -0700, Nikhil Rao wrote:
> On Sun, Oct 3, 2010 at 8:08 PM, Mike Galbraith <efault@gmx.de> 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
next prev parent reply other threads:[~2010-10-08 7:22 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-28 0:29 [PATCH 0/3][RFC] Improve load balancing when tasks have large weight differential Nikhil Rao
2010-09-28 0:29 ` [PATCH 1/3] sched: set group_imb only a task can be pulled from the busiest cpu Nikhil Rao
2010-09-28 0:29 ` [PATCH 2/3] sched: drop group_capacity to 1 only if remote group has no running tasks Nikhil Rao
2010-09-28 23:04 ` Suresh Siddha
2010-10-11 21:20 ` Nikhil Rao
2010-09-28 0:29 ` [PATCH 3/3] sched: do not consider SCHED_IDLE tasks to be cache hot Nikhil Rao
2010-09-28 13:57 ` [PATCH 0/3][RFC] Improve load balancing when tasks have large weight differential Mike Galbraith
2010-09-28 21:15 ` Nikhil Rao
2010-09-29 1:45 ` Mike Galbraith
2010-09-29 19:32 ` Nikhil Rao
2010-10-04 3:08 ` Mike Galbraith
2010-10-06 8:23 ` Nikhil Rao
2010-10-08 7:22 ` Mike Galbraith [this message]
2010-10-08 20:34 ` Nikhil Rao
2010-10-10 10:15 ` Mike Galbraith
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