On Mon, Dec 03, 2007 at 10:11:51AM +0100, H?kon Bugge wrote: > But > there are cases where you cannot; a) the > "decomposition parallel efficiency" is not good > enough or b) the processes need a huge (shared) table.
You can accomplish (b) using a mmaped file, which is much easier than hybrid programming. I agree that (a) is theoretically useful, but I have only once seen a benchmark situation where (a) was the case. I have seen several situations where a hybrid code had a 1D MPI decomposition and "needed" OpenMP for more scaling, but could have been a pure MPI 2D or 3D code, with less complexity than the hybrid code. -- greg _______________________________________________ Beowulf mailing list, [email protected] To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
