Re: 2.6.21-rc1: known regressions (v2) (part 2)

Ingo Molnar
2007-02-27T08:44:59Z

* Michal Piotrowski <michal.k.k.piotrowski@gmail.com> wrote:

> Thomas Gleixner napisał(a):
> > Adrian,
> >
> > On Mon, 2007-02-26 at 23:05 +0100, Adrian Bunk wrote:
> >> Subject : kernel BUG at kernel/time/tick-sched.c:168 (CONFIG_NO_HZ)
> >> References : http://lkml.org/lkml/2007/2/16/346
> >> Submitter : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
> >> Handled-By : Thomas Gleixner <tglx@linutronix.de>
> >> Status : problem is being debugged
> >
> > The BUG_ON() was replaced by a warning printk(). The BUG_ON() exposed a
> > problem with the SMT scheduler. See below.
> >
> >> Subject : BUG: soft lockup detected on CPU#0
> >> NOHZ: local_softirq_pending 20 (SMT scheduler)
> >> References : http://lkml.org/lkml/2007/2/20/257
> >> Submitter : Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
> >> Handled-By : Thomas Gleixner <tglx@linutronix.de>
> >> Ingo Molnar <mingo@elte.hu>
> >> Status : problem is being debugged
> >
> > Patch available, not confirmed yet.
> >
>
> I can confirm that the bug is fixed (over 20 hours of testing should
> be enough).

thanks alot! I think this thing was a long-term performance/latency
regression in HT scheduling as well.

Ingo