Subject: Re: mutex fault
To: Kazushi Marukawa <>
From: Manuel Bouyer <>
List: tech-kern
Date: 12/13/2007 13:28:18
On Thu, Dec 13, 2007 at 09:21:20PM +0900, Kazushi Marukawa wrote:
> Hi,
> This is an update of my situation.
> I have been using NetBSD 11/27 with LOCKDEBUG and Manuel's
> last patch.  It is running over 3 days without any crashes.
> However, it is running slow.  Especially, WinXP running on
> xen3-hvm is really slow.  Maybe alot of locks to run WinXP?

HVM triggers a lot of interrupts, which I think requires locks to get to
the qemu-dm process. As LOCKDEBUG makes the lock primitives much more
expensive, this may explain it.

> I'm afraiding this will not crash.  Because I'm thinking
> that this slowness may hide the rare condition causing the
> crash previously.
> Anyway, it's running, so I will leave it as is for a while
> to see whether it crashes or not.  If you have any idea to
> try, please let me know.  Thanks.

I'm running a LOCKDEBUG kernel now as well, and I didn't see a crash either.

Manuel Bouyer, LIP6, Universite Paris VI. 
     NetBSD: 26 ans d'experience feront toujours la difference