Any way to debug a hard lockup?

[Vulpes Velox]

On Wed, 07 Jul 2004 14:03:31 -0500 (CDT)
"Conrad J. Sabatier" <conrads at cox.net> wrote:

> For the last few days, my amd64 box (Athlon 64 3200+, 5.2-CURRENT,
> updating just about daily lately) has been locking up hard fairly
> often, and I have no clue as to why.
> 
> Checking the logs after rebooting reveals nothing at all out of the
> ordinary.  The box just "seizes up" and that's that.  Only thing to
> do is a power-down and restart.
> 
> Changing from SCHED_ULE to SCHED_4BSD appears to make no difference
> at all.
> 
> My other box, an older (32-bit) Athlon, has been rock stable.  I've
> been keeping both machines updated simultaneously to exactly the
> same revisions, using as near-identical system settings as possible
> also, the main difference being I'm running X.org/GNOME on the amd64
> box and no X on the i386 box.
> 
> Any suggestions?  Instinct tells me it may be a problem with some of
> the ports I'm running (X.org/GNOME, hence the Cc:s), but how to
> verify? Sure, I could run without X a while and see how it goes, but
> that still won't help to isolate the problem, if it is, in fact,
> port-related.

What gfx card(and pci or agp?) and what driver?

If this is a nvidia card, turn off the screen saver... there appears
to be a GL problem with the nvidia driver that seems to cuase them to
lock up occasionally... or least that has been my experience with
xscreensaver on both XFree86 and Xorg. On both 5.2.1 and 4stable.