This DTrace provider adds hooks to the Pharo VM for probes such as method enter/return, object allocation, GC begin and end, and process switching.

DTrace allows unprecedented view across all layers of Smalltalk software. With DTrace we can simultaneously observe and correlate events from Smalltalk, the VM, and the OS.

Please check out the accompanying blog post for instructions to build your own DTrace-instrumented VM:

http://www.adrian-lienhard.ch/blog?dialog=smalltak-meets-dtrace

There's also a pre-compiled VM for OS X.

The above linked post provides detailed introductions with examples.