Newsgroups: comp.parallel.mpi
From: raja@convex.com (Raja Daoud)
Subject: Re: MPI question
Organization: Hewlett-Packard Co.; Convex Division
Date: 1 Jun 1996 15:42:30 -0500
Message-ID: <4oq9vm$g5f@tbag.rsn.hp.com>

Steve Barnard  <steve@megafauna.com> wrote:
>blocking buffered sends (Bsend) were available, but now I see that a 
>non-blocking version (Ibsend) is there, too.

Note that Bsend doesn't block, and both Bsend and Ibsend consume
resources (i.e. envelopes) and thus must abort/error if resources are
depleted.  The suggested implementation of Bsend (page 36) calls Isend.
The same issue of running out of resources is thus inherited.  Either
the programmer is careful in the use of non-blocking calls (including
"blocking" Bsend) or the application aborts/errors at some level as it
is scaled.  This "some level" is implementation dependent.  So in this
gray area, for non-scalable applications, it's just a matter of tuning
parameters for particular systems.  Hope that helps.

--Raja

-=-
Raja Daoud					Hewlett-Packard Co.
raja@rsn.hp.com					Convex Division

