Re: find_busiest_group using lots of CPU

Peter Zijlstra
2009-10-06T12:05:05Z

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.

Thanks!