Re: 2.6.30-rc1 - nmi_watchdog broken?

From: Ingo Molnar
Date: Tue Apr 14 2009 - 04:43:12 EST



* Ed Tomlinson <edt@xxxxxx> 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?

Ingo
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