Mateus, MPI guarantee message ordering per communicator per peer. In other words any message going from peer A to peer B in the same communicator will be __matched__ on the receiver in the exact same order as they were sent (this remains true even for multi-threaded libraries). MPI does not mandate any other type of ordering, such as between communicators or between different pairs of processes.
Now, what I previously said is only true for the matching logic. Completion of message reception is a totally different thing. George. On Jan 24, 2012, at 23:53, Mateus Augusto <teleomin...@yahoo.com.br> wrote: > After a read: http://blogs.cisco.com/performance/more_traffic/ > I understood that if a large message is sent and then a short message is > sent, then the short message can reach before. But what if the messages have > the same size, and are small enough so that no fragmentation occurs, the > ordering in delivery will be guaranteed? > > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users
