From: Ingo Molnar <mingo@elte.hu>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jens Axboe <jens.axboe@oracle.com>,
Linux Kernel <linux-kernel@vger.kernel.org>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Subject: Re: find_busiest_group using lots of CPU
Date: Tue, 6 Oct 2009 14:14:26 +0200 [thread overview]
Message-ID: <20091006121425.GA24070@elte.hu> (raw)
In-Reply-To: <1254830661.21044.275.camel@laptop>
* Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> On Tue, 2009-10-06 at 13:20 +0200, Jens Axboe wrote:
> > > > io_schedule() straight into find_busiest_group() leads me to think this
> > > > could be SD_BALANCE_NEWIDLE, does something like:
> > > >
> > > > for i in /proc/sys/kernel/sched_domain/cpu*/domain*/flags;
> > > > do
> > > > val=`cat $i`; echo $((val & ~0x02)) > $i;
> > > > done
> > > >
> > > > [ assuming SCHED_DEBUG=y ]
> > > >
> > > > Cure things?
> > >
> > > I can try,
> >
> > It does, it's gone from the profiles.
>
> Hrmm,. ok. I'll go prod at the NEWIDLE bits to see if anything stands
> out.
>
> If only perf-annotate could generate annotated C... maybe I'll look at
> that.
hey it can do that - build a vmlinux with DEBUG_INFO=y and it should
just work :-)
Ingo
prev parent reply other threads:[~2009-10-06 12:15 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-30 8:18 find_busiest_group using lots of CPU Jens Axboe
2009-10-05 12:31 ` Peter Zijlstra
2009-10-06 7:51 ` Jens Axboe
2009-10-06 11:20 ` Jens Axboe
2009-10-06 11:47 ` Ingo Molnar
2009-10-06 11:56 ` Jens Axboe
2009-10-06 12:04 ` Peter Zijlstra
2009-10-06 12:14 ` Ingo Molnar [this message]
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