Help diagnosing system hangs?

[Nikolas Britton]

On 8/23/05, Eric Rescorla <ekr at rtfm.com> wrote:
> I've recently been experiencing frequent hangs with FreeBSD 5.3-RELEASE-p20.
> Strangely, this didn't appear to happen with 5.3-RELEASE or before
> a few months ago.
> 
> My platform is a P4-2.8 GHz (dmesg appended at end).
> 
> The behavior is that X freezes (sorry, I can't say if the clock is still
> working because I forgot to check) and sshing into the box hangs.  A
> hard reboot clears things and the box starts normally, except that it
> fscks as expected. Nothing appears in /var/log/messages, etc.
> 
> Because this problem started fairly recently, my one guess is that this
> is somehow related to the hyperthreading fix in SA-05:09. This processor
> allegedly has hyperthreading but I'm running GENERIC. Any possibility
> this could be responsible for hanging somehow?

Have you ruled out hardware problems, what makes you think it's
FreeBSD? Is this problem random? etc.