Re: 2.5 Problem Status Report

[Oleg Drokin <green@namesys.com>]

Hello!

On Wed, Sep 11, 2002 at 09:26:40AM +0200, Ingo Molnar wrote:
> > > >    BUG at kernel/sched.c        open                  10 Sep 2002
> > > What exactly is this?
> > Looks like this is my bugreport for BUG in kernel/sched.c:944 in the middle
> > of partition parsing output on boot.
> > Subject of email was
> > '2.5.34 BUG at kernel/sched.c:944 (partitions code related?)'
> > msgid: 20020910175639.A830@namesys.com
> very strange backtrace:
>  >>EIP; c0115818 <schedule+18/4a0>   <=====
>  Trace; c01053a0 <default_idle+0/40>

I noticed it too.

> i've once seen the 2.5 IDE code doing a schedule_timeout() from an IRQ
> handler, but the above has to be something else. Could you hack sched.c to
> print out the exact preemption count? It could be a preempt-count
> underflow due to an unbalanced spin_unlock, or an inbalanced
> preempt_enable. [or the IRQ code - but i doubt that, we'd have seen

I have preemption disabled.

> problems much earlier if this was the case.]

> Oleg, do you have CONFIG_DEBUG_SPINLOCK enabled? That should catch an
> unbalanced spin_unlock().

Yes, I do.
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_SLAB=y
CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_HIGHMEM=y

Bye,
    Oleg