On Fri, Jun 19, 2009 at 1:17 PM, Eugene Loh <Eugene.Loh@sun.com>
I need to do some other stuff, but might spend time on this later. For now, I'll just observe that your sends are rendezvous sends. E.g., if you decrease BUFLEN from 25000 to 2500 (namely, from over 4K to under 4K), the behavior should change (to what you'd expect). That may or may not help you, but I think it's an important observation in reasoning about this behavior.
Mark Bolstad wrote:
I have a small test code that I've managed to duplicate the results from a larger code. In essence, using the sm btl with ISend, I wind up with the communication being completely serialized, i.e., all the calls from process 1 complete, then all from 2, ...