A couple of (lagged!) updates on my FreeBSD/PmcTools work:
More recently, Nokia, via Jeff Roberson, contributed basic support for the PMCs in the Core/i7™ CPU, the next member in the Core™ family of CPUs (SVN #187761).
With these additions PmcTools supports most Intel CPUs that have PMCs in them. (I have plans to finish support for 166Mhz Pentium MMX™ CPUs soon.)
A couple of tricky bugs were tracked down and fixed:
The NMI handler code I had written for the amd64 architecture needed to be more robust than it was. Fixed in SVN #188065.
A bug in callchain capture code that would appear only under high loads and only on SMP machines. Fixed in SVN #186037.
Thanks to Artem Belevich, Fabien Thomas, George Neville-Neil and Jeff Roberson for their assistance with debugging.