Re: find_busiest_group using lots of CPU

Ingo Molnar
2009-10-06T12:15:19Z

* 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