Re: ZFS and deadlock with {nullfs,NFS}

From: Joe Marcus Clarke <marcus_at_FreeBSD.org>
Date: Wed, 20 Jun 2007 12:17:54 -0400
On Wed, 2007-06-20 at 12:03 -0400, Kris Kennaway wrote:
> On Wed, Jun 20, 2007 at 11:53:43AM -0400, Joe Marcus Clarke wrote:
> > I've resurrected by amd64 Tinderbox with a ZFS base, and I've been
> > seeing a 100% reproducible deadlock when I use it with either localhost
> > NFS or nullfs.  When this occurs, the CPU is 100% idle, but I can no
> > longer connect via SSH, and the box will only reboot from the debugger.
> > I know there are some tuning bits I can tweak, but all I've run across
> > is for memory consumption.  Any pointers would be helpful.  I'm also at
> > the debugger, so if there is anything I can do to help troubleshoot why
> > this is happening, please let me know.  
> > 
> > This box is -CURRENT as of June 19, 2007.  It has a GENERIC kernel minus
> > devices I do not have (i.e. SMP kernel).  I am currently using nullfs
> > for the Tinderbox.  The process that most regularly locks up is mtree.
> > Here is the trace:
> 
> > A full process list from the debugger can be found at
> > http://www.marcuscom.com/downloads/cobbler_proc.txt .
> 
> 404 at the moment, but look for processes involving zil* in the
> backtrace.  I had to disable zil (vfs.zfs.zil_disable=1 tunable) to
> prevent low-memory deadlocks on my machines.  Since then it's been
> fine.

Fixed, sorry.

> 
> You may also wish to use my patches (see the archives) to improve
> performance and low-memory behaviour.

Thanks for the advice.  I'll check.  I didn't think low memory since it
didn't look like I was using much.  Even now with the box locked, I have
1035 MB free with no swap in use (this box has 2 GB total).

Joe

-- 
Joe Marcus Clarke
FreeBSD GNOME Team      ::      gnome_at_FreeBSD.org
FreeNode / #freebsd-gnome
http://www.FreeBSD.org/gnome

Received on Wed Jun 20 2007 - 14:18:12 UTC

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