7.2-release/amd64: panic, spin lock held too long

[Dan Naumov]

I just got a panic following by a reboot a few seconds after running
"portsnap update", /var/log/messages shows the following:

Jul  7 03:49:38 atom syslogd: kernel boot file is /boot/kernel/kernel
Jul  7 03:49:38 atom kernel: spin lock 0xffffffff80b3edc0 (sched lock
1) held by 0xffffff00017d8370 (tid 100054) too long
Jul  7 03:49:38 atom kernel: panic: spin lock held too long

/var/crash looks empty. This is a system running official 7.2-p1
binaries since I am using freebsd-update to keep up with the patches
(just updated to -p2 after this panic) running with very low load,
mostly serving files to my home network over Samba and running a few
irssi instances in a screen. What do I need to do to catch more
information if/when this happens again?

- Sincerely,
Dan Naumov