This blog forms part of the http://performanceGuru.com website which focuses on performance tuning UNIX-like Operating Systems (including Linux).
Prasanna Panchamukhi announced today
that he has produced a patch against the 2.6.13 kernel which introduces the ability to probe user space. This functionality will provide one of the current major missing pieces in Systemtap.
For an introduction to Kprobes see the introductory article on LWN
(If you are reading this post because this constitues a production endorsement of Systemtap then please see my further comments