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

Thomas Gleixner
2007-02-27T08:21:50Z

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.

tglx