Re: 2.6.30-rc1 - nmi_watchdog broken?

Ed Tomlinson
2009-04-14T12:33:01Z

On Tuesday 14 April 2009 04:42:32 Ingo Molnar wrote:
>
> * Ed Tomlinson <edt@aei.ca> wrote:
>
> > Hi,
> >
> > I've been having fun finding bugs in 30-rc1. One of them is a
> > hard freeze. I've not seen this type of problem on this hardware
> > before 30-rc1 - so I doubt if its hardware. The best way I know
> > to debug a hard hang is with the nmi_watchdog. I just cannot get
> > it to work.
>
> [ Btw., have you tried CONFIG_PROVE_LOCKING=y - does it produce
> anything before or at the hard lockup point? ]
>
> > The system is a 3 core amd cpu on a 790gx chipset.
> >
> > If I boot the nmi_watchdog=1 it complains that lapci is not
> > available and the boot stops. Same problem if I change the
> > clocksource to tsc, If I disable highres timers it panics. If I
> > use nmi_watchdog=2 it panics. Am I doing something wrong or have I
> > hit a bug?
> >
> > Logs of boots with and without highres timers inlined below.
>
> hm, nmi_watchdog=1 acting funny is not unheard of. But
> nmi_watchdog=2 should really work. How does it panic, do
> you have a capture of that?

I had not tried nmi_watchdog=2 highres=off. This works. Looks like there
is a conflict between highres timers and nmi_watchdog here.

Any ideas?

TIA
Ed

PS. I'll build with config_prove_locking tonight.