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Subject: Re: [OMPI users] Bug in 1.3.2?: sm btl and isend is serializes
From: Eugene Loh (Eugene.Loh_at_[hidden])
Date: 2009-06-19 13:17:15


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, ...

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.