Newsgroups: comp.parallel.mpi
From: James Allwright <jra@ecs.soton.ac.uk>
Subject: Question : buffer size for MPI_BSEND
Organization: Electronics and Computer Science, University of Southampton
Date: 23 Jun 1995 13:29:55 GMT
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Message-ID: <3sefkj$cd@bright.ecs.soton.ac.uk>

I have a question which does not seem to be answered in the MPI standard as
far as I can tell. If you want to send a message using MPI_BSEND and you
know how big it is, how big do you have to make the buffer in 
MPI_BUFFER_ATTACH ?

In mpich, the answer seems to be 14 INTs larger than the message to be
sent, which I discovered by trial and error. It seems to me that there should
be some predefined constant to tell you the amount of extra space you need.

James Allwright,
Department of Electronics and Computer Science,
University of Southampton, UK


