Newsgroups: comp.parallel.mpi
From: tst@dcs.ed.ac.uk (Tristan Tarrant)
Subject: Re: Problem with LAM 6.0?
Organization: Department of Computer Science, Edinburgh University
Date: Wed, 28 Aug 1996 16:06:01 GMT
Message-ID: <DwuvE2.LzJ.0.staffin.dcs.ed.ac.uk@dcs.ed.ac.uk>

Richard Barrett (rbarrett@lanl.gov) wrote:
: Tristan Tarrant wrote:
: > 
: > Under LAM 6.0 (with the latest patches) running the following:
: Ok, so the implementors have addressed this, but how about an
: applications type? Do you have an application that would do
: something like this (i.e. use thousands of communicators)?
: If so, I would be interested in at least a brief description.
: 
: I understand that memory leaks are importants to plug no matter
: how obscure, so I'm just curious...
: 
: Richard
: 
:  
: >     for (i=0; i<100000; i++) {
: > 
: >         MPI_Comm_dup(MPI_COMM_WORLD, &comm);
: >         MPI_Comm_free(&comm);

In a library functions written using MPI it is common to create new communicators 
in order to invoke a separate communications context. Since this may be done at
the start of a parallel call and the communicator freed at the end of the
call, repetitive calls to these functions would result in the problems
described. 

Tristan

