By James Reinders (Intel)
A tutorial at Supercomputing 2009 looked at the pros and cons of mixing MPI and OpenMP in a single program, and was taught by Rolf Rabenseifner (University of Stuttgart), Georg Hager (University of Erlangen) and Gabriele Jost (Texas Advanced Computing Center/Naval Postgraduate School).
Not too long ago, early experiments with this didn’t show it was worth the trouble. But that has all changed, because nodes continue to offer more and more SMP parallelism because of more sockets and more cores per sockets and even more hardware threads per core.
What really struck me - was how much of the tutorial was about “little things” that are simply a fact of life now. Will they go away in the future? I think so - but it really tells us where we are today.
