panic "Sleeping thread owns a non-sleepable lock" via cv_timedwait_signal, was "rsync over NFS"

[Rick Macklem]

Konstantin Belousov wrote:
> On Wed, Oct 03, 2012 at 07:26:47PM +0200, Norbert Aschendorff wrote:
> > On 10/03/2012 05:54 PM, Konstantin Belousov wrote:
> > > So do you use nullfs exported mounts ? And stable ?
> > > Can you try to remove nullfs from the set up ?
> >
> > Yes, I am using nullfs for the exports (mounting the exported
> > directories to subdirectories of /srv). In the FreeBSD man pages and
> > the
> > documentation, the V4 export line in /etc/exports is often set to /,
> > but
> > as I come from Linux where /etc/exports looks completely different,
> > I
> > just followed my habits.
> >
> > As I wrote this, I executed the critical operation. It's finished
> > and
> > the FreeBSD server still runs *yay* :) So it's quite likely that the
> > problem stems from the nullfs mount.
> >
> > I just remember an issue I already wanted to tell: Before the server
> > crashed, the nfsd process ('nfsd: server') used 100% CPU (one core),
> > but
> > without progress on client side. Usually, the nfsd uses only up to
> > 10%
> > cpu time when rsyncing (values taken from htop - 100% = one used
> > CPU).
> >
> > ...aaand I just run it once more, and it worked again :)
> 
> Can you try HEAD kernel ?
Kostik, thanks for thinking of this. The crash had me baffled, rick.