Newsgroups: comp.parallel.mpi
From: salo@mrjones.engr.sgi.com (Eric Salo)
Subject: Re: T3D MPI Send/Wait (was Re: PVM send buffers)
Organization: Silicon Graphics, Inc.  Mountain View, CA
Date: 4 Apr 1996 19:36:58 GMT
Message-ID: <4k18cq$ie7@murrow.corp.sgi.com>

> The most straightforward conversion from csend/crecv for a T3d would be
> to MPI_Send/MPI_Recv.  That is a match for the semantics.  You should also
> expect performance reasonably close to shmem_put, at least with respect to
> bandwidth.  You might expect higher latency since you are asking for more
> in the way of semantics.  

Rusty, I'm not sure that I agree. Doesn't csend always return even if the
matching receive has not yet been posted? We've been bitten many times by
NX ports that used MPI_Send as a drop-in replacement for csend because we
don't buffer most messages by default. MPI_Bsend is a better match for
the semantics, I think.

Eric Salo         Silicon Graphics Inc.             "Do you know what the
(415)933-2998     2011 N. Shoreline Blvd, 7L-802     last Xon said, just
salo@sgi.com      Mountain View, CA   94043-1389     before he died?"


