NOTE TO PEOPLE WHO THINK THAT FreeBSD 8.x IS SLOW: FreeBSD 8.x has many debugging features turned on, in both the kernel and userland. These features attempt to detect incorrect use of system primitives, and encourage loud failure through extra sanity checking and fail stop semantics. They also substantially impact system performance. If you want to do performance measurement, benchmarking, and optimization, you'll want to turn them off. This includes various WITNESS- related kernel options, INVARIANTS, malloc debugging flags in userland, and various verbose features in the kernel. Many developers choose to disable these features on build machines to maximize performance. (To disable malloc debugging, run ln -s aj /etc/malloc.conf.)
20090915: ZFS snapshots are now mounted with MNT_IGNORE flag. Use -v option for mount(8) and -a option for df(1) to see them.
20090813: Remove the option STOP_NMI. The default action is now to use NMI only for KDB via the newly introduced function stop_cpus_hard() and maintain stop_cpus() to just use a normal IPI_STOP on ia32 and amd64.