DTrace entry in /usr/src/UPDATING

20080826:
DTrace support was merged to STABLE today. In the best
tradition of “the dog ate my homework”, subversion decided
that the commit message was too large and opted not to send
it. It was a stealth commit!

A ‘make buildkernel’ will now default to build the kernel
and modules with both DTrace kernel hooks and CTF data ready
for DTrace.

After you have installed both world and the kernel, and
rebooted, you can ‘kldload dtraceall’ to load all the DTrace
kernel modules and then you’re set to run the ‘dtrace’
client (as root).

For DTrace documentation, refer to:

We are limited to kernel tracing at the moment, so the pid
provider is not available.

For the syscall provider, note that the arguments to the
return probes are the same as for the entry probes.

hehe, gotta love Subversion 🙂