in reply to Dreaming of a Better Profiler

SamTregar says:
# don't know how to write an interupt handler. I think it would require a kernel module under Linux, which would be entirely new ground for me.
I wouldn't use a Kernel module; I think that would be hard. I would replace Perl's standard 'runops' loop with a custom one. See perlguts: "Pluggable runops".

Hope this helps.