Hard Hang, nothing in logs / no panics

[Kris Kennaway]

On Fri, May 11, 2007 at 04:21:25PM -0500, Roger Miranda wrote:
> On Friday 11 May 2007 16:00, Kris Kennaway wrote:
> > See the developers handbook chapter on kernel debugging.
> 
> Kris,  I have gone through the kernel debugging sections of the developers 
> handbook.  The one problem is when I get a hard hang, I do not get any error 
> or panics.  And there is no crash or dump data on reboot. Yes. I have enabled 
> DDB and KDB and a dumpdir (in /etc/rc.conf)
> 
> Am I missing something in the kernel debugging section?  I see "11.9 Debugging 
> Deadlocks" talk about Deadlocks.  But at the time of the lock I have no way 
> of doing a ps or really anything as the system is locked up solid.

You missed that the debugger is there to debug bugs (including
deadlocks).  Break to the debugger and obtain the necessary debugging
:)

Kris