Diagnosing runaway CPU in a .Net production application

Question

Does anyone know of a tool that can help me figure out why we are seeing runaway CPU in a managed app?

What I am not looking for:

Answer 1

If you have managed code in lieu of a profiler worth using I've found that throwing a log message into your code is damn useful for spotting infinite loops and general multi thread progressions.

i.e

step 1 msg
step 2 msg

thread now 100% and no step 3 msg = bug.