crashdump "watchdog timeout" - Howto get useful information?

[John Baldwin]

On Tuesday 01 September 2009 1:45:44 pm Peter Much wrote:
> 
> Dear all,
> 
> could anybody share some insight (or pointers to docs) on how to
> approach an analysis of a "watchdog timeout" crashdump?
> 
> I hopefully have the necessities in place  (that is, I can load
> the dump into ddd and actually see things).
> 
> But I have no real idea about where to start looking for interesting
> things - some structure from where to unroll what the system was
> doing (or not doing).
> The "developers handbook" mainly explains about figuring the cause 
> of the crash - but in my case this is obvious, it is the watchdog I 
> have configured.
> 
> Since this is a reproducible issue, ideas on things that could be 
> configured beforehand could also be useful.

I would examine the state of the processes in the system first.  If all the 
CPUs are idle but some threads are blocked on locks you might have a 
deadlock, etc.

You can use the gdb scripts at http://www.FreeBSD.org/~jhb/gdb/ in kgdb to 
figure some of that stuff out (source gdb6 from within gdb.  I usually start 
with 'ps').

-- 
John Baldwin