Why could Shark be so slow?

I'm trying to profile Ruby interpreter. I run shark -i ./ruby bm_sudoku.rb or something like that, the script finishes in less than a second, and then Shark goes to "CHUDData - Analyzing samples... 99.3%.." point and st开发者_运维问答ays there frozen for 10 minutes or so. It finishes eventually, it's just so ridiculously slow it's pretty much unusable.

Version I have here is OSX 10.5, shark 4.6.1 (227).

Any ideas what that might be?

There's some sort of strange problem in 10.5 with Shark being glacially slow loading symbols which can take several minutes. I don't see the problem in 10.6, and that seems to mirror the same behaviour seen by Chromium developers.

Try Instruments -- the CPU sampler is similar to shark and it is a lot faster. No pause at the end.