7.1 hangs in cache_lookup mutex?

[Kevin Oberman]

> Date: Tue, 24 Feb 2009 15:46:28 -0600
> From: Guy Helmer <ghelmer at palisadesys.com>
> Sender: owner-freebsd-stable at freebsd.org
> 
> I think I may have found a clue regarding some of the hangs I'm seeing 
> on FreeBSD 7.1.
> I have a program (kvoop), compiled under FreeBSD 6 and using 
> compatibility libraries under FreeBSD 7, that seems to be consistently 
> involved during these hangs.  This time, I noticed that many processes 
> are stopped, waiting on the ufs lock.  I can't tell for certain, but I 
> assume this kvoop process 33203 is blocking the other processes.  The 
> kvoop process looks to me like it is waiting for a mutex, but nothing 
> shows up being deadlocked.  Am I on the right track?  Is there something 
> else I should be looking for?

For whatever it is worth, I have seen this three times over the past
couple of weeks. My system is RELENG_7 of Feb. 7. I have no real
information to add other than that I have also had this problem. When it
happens, the only way out is a reboot. It hit me twice while updating
Xorg. 

Thanks for your efforts! I hope someone can track down what is triggering
with this.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4  EADA 927D EBB3 987B 3751