> Date: Thu, 4 Jun 2009 11:14:16 +1000 > From: Lars Andersson <lars...@gmail.com> > Subject: [OMPI users] Receiving MPI messages of unknown size > To: us...@open-mpi.org > > When using blocking message passing, I have simply solved the problem > by first sending a small, fixed size header containing the size of > rest of the data, sent in the following mpi message. When using > non-blocking message passing, this doesn't seem to be such a good > idea, since we cant post the main data transfer until we have received > the message header... It seems to take away most of the advantages on > non-blocking io in the first place.
If enough messages are small enough, a medium sized message with fixed header and variable data eliminates most of the second message overhead.
