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

Peter Zijlstra
2008-02-01T07:51:59Z

On Fri, 2008-02-01 at 03:04 +0100, Rafael J. Wysocki wrote:
> On Friday, 1 of February 2008, Rafael J. Wysocki wrote:
> > Hi,
> >
> > This is related to the problem I reported earlier this week:
> > http://lkml.org/lkml/2008/1/30/554
> >
> > Apparently artswrapper, run by KDE in openSUSE 10.3 with a real time priority,
> > is mishandled by the scheduler. The problem is that after the user logs out,
> > artswrapper stays in TASK_RUNNING forever and prevents other tasks from being
> > scheduled on the CPU occupied by it. In this state it also breaks suspend and
> > hibernation (it cannot be frozen).
> >
> > Since the problem is 100% reproducible on my test boxes, I carried out a
> > bisection which turned out the following commit:
> >
> > commit 6f505b16425a51270058e4a93441fe64de3dd435
> > Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
> > Date: Fri Jan 25 21:08:30 2008 +0100
> >
> > sched: rt group scheduling
> >
> > I'm now checking if the problem disappears after reverting this patch (along a
> > couple of dependent ones).
>
> Yes, it does.
>
> Please let me know what I can do to debug it further.

It arts run as root, or does it use RLIMIT_RTPRIO to allow users to
execute realtime tasks?