Re: [Regression] 2.6.24-git9: RT sched mishandles artswrapper (bisected)

Peter Zijlstra
2008-02-06T21:44:40Z

On Wed, 2008-02-06 at 19:25 +0100, Rafael J. Wysocki wrote:
> On Wednesday, 6 of February 2008, Peter Zijlstra wrote:
> >
> > On Wed, 2008-02-06 at 09:40 +0100, Dmitry Adamushko wrote:
> > > On 06/02/2008, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > > > On Tuesday, 5 of February 2008, Dmitry Adamushko wrote:
> > > > > Rafael, any progress with this issue? (a few questions below).
> > > > >
> > > > > > >
> > > > > > > Does this artsmessage thing also run with RT priority?
> > > > > >
> > > > > > Well, it's in a strange state (after it's broken). From top:
> > > > > >
> > > > > > PR = -51
> > > > > > NI = 0
> > > > > > S = R
> > > > > > %CPU = 0.0
> > > > > > %MEM = 0.0
> > > > >
> > > > > cat /proc/$PID/stat ; sleep 3; cat /proc/$PID/stat ?
> > > > > cat /proc/sched_debug; sleep 3 ; cat /proc/sched_debug
> > > >
> > > > Well, instead please find appended a test program that allows me to trigger
> > > > the issue.
> > >
> > > Great, I'll look at this problem in the everning (sure, if nobody else
> > > is faster :-).
> >
> > Yeah, it seems fixed here (after I made my current queue compile for
> > this silly CONFIG_USER_SCHED thing again).
> >
> > I'm now refusing realtime tasks in groups that do not have real-time
> > bandwidth assigned.
>
> If you're referring to this patch: http://lkml.org/lkml/2008/2/4/332 , then
> sorry, but it doesn't fix the issue for me, with the attached config.

Well, that whole queue. Your test program just failed to obtain realtime
scheduling but didn't hang. I'll test your full config.