This blog forms part of the http://performanceGuru.com website which focuses on performance tuning UNIX-like Operating Systems (including Linux).
After its recent success with other dynamic languages, such as Ruby and Java, it seems dtrace can now profile Perl code. The work done by Alan Burlinson is embryonic and does not catch a small amount of possible function entry and exit points but nonetheless it is a very valuable piece of work. I would imagine it will not take long for people to build on Alan's work and solve the issues he raises in his post.
Alan's post about how he went about instrumenting Perl is located at:Alan's Blog Entry
Hopefully the various dynamic language observability efforts, made in relation to dtrace, will ensure that in future the intepreters used for these languages will be designed with observability in mind and will therefore be simpler and more efficient to instrument.