ZFS Panic after freebsd-update

[Scott Sipe]

Hello,

I have not had much time to research this problem yet, so please let me
know what further information I might be able to provide.

This weekend I attempted to upgrade a computer from 8.2-RELEASE-p3 to 8.4
using freebsd-update. After I rebooted to test the new kernel, I got a
panic. I had to take a picture of the screen. Here's a condensed version:

panic: page fault
cpuid = 1
KDB: stack backtrace:
#0
#1
#2
#3
#4
#5
#6
#6
#6
#6
#6
#6
FreeBSD xeon.cap-press.com 8.2-RELEASE-p3 FreeBSD 8.2-RELEASE-p3 #0: Tue
Sep 27 18:45:57 UTC 2011
root at amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC
 amd64