> Thanks for the explanation. I am using GigEth + Open MPI and the
> buffered MPI_BSend. I had already noticed that top behaved
> differently on another cluster with Infinibandb + MPICH.
> So the only option to find out how much time each process is waiting
> around seems to be to profile the code. Will gprof show me anything
> useful or will I have to use a more sophisticated (any free ones?)
> parallel profiler?
Another frequently asked question! I can try to add a FAQ
entry/category. There are a number of free options including
Sun Studio http://developers.sun.com/sunstudio/
The only one I've really used is Sun Studio.
Jumpshot *might* work with Open MPI, I forget. Or, it might be more an