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

[Norbert Aschendorff]

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 :)

--Norbert