c++ - How to profile OpenMP bottlenecks

Question

I have a loop that has been parallelized by OpenMP, but due to the nature of the task, there are 4 critical clauses.

What would be the best way to profile the speed up and find out which of the critical clauses (or maybe non-critical(!) ) take up the most time inside the loop?

I use Ubuntu 10.04 with g++ 4.4.3

Answer 1

Scalasca is a nice tool for profiling OpenMP (and MPI) codes and analyzing the results. Tau is also very nice but much harder to use. The intel tools, like the vtune, are also good but very expensive.