From hillson@ait.nrl.navy.mil Tue Dec 28 12:19:40 1999
Date: Tue, 15 Jun 1999 15:57:22 -0400 (EDT)
From: Roger Hillson <hillson@ait.nrl.navy.mil>
To: tapulika@npac.syr.edu
Subject: fyi:  resetting max. buffer size

>From hillson@ait.nrl.navy.mil  Tue Jun 15 15:22:32 1999
Mime-Version: 1.0
Date: Tue, 15 Jun 1999 15:21:56 -0500
To: "Tran, Tuan" <Tran@metsci.com>
From: Roger Hillson <hillson@ait.nrl.navy.mil>
Subject: Re: MPI_Bsend
Cc: hillson

>Roger,
>
>I'm getting the error msg below while running our 1000 objs scenario on dax
>using 2 and 4 nodes.  Could you please take a look at this.
>
>Tuan
>
>
>------ mpi 2 nodes
>
>ParNSS.mpi: Rank 0: MPI_Bsend: Invalid buffer pointer: Insufficient space
>available in user-defined buffer
>ParNSS.mpi: Rank 1: MPI_Bsend: Invalid buffer pointer: Insufficient space
>available in user-defined buffer
>
>------ mpi 4 nodes
>
>ParNSS.mpi: Rank 2: MPI_Bsend: Invalid buffer pointer: Insufficient space
>available in user-defined buffer
>ParNSS.mpi: Rank 3: MPI_Bsend: Invalid buffer pointer: Insufficient space
>available in user-defined buffer
>ParNSS.mpi: Rank 0: MPI_Bsend: Invalid buffer pointer: Insufficient space
>available in user-defined buffer

Tuan,

The buffer capacity for MPI_Bsend is set by the user in MPI_Globals.H.
Increase the value of MPI_BUFFER_SIZE.  The maximum  theoretical size is
MAX_INT, but I usually set the variable to some fraction of this --
for example:

const static int MPI_BUFFER_SIZE = MAX_INT/10;

Unfortunately, MPI does not provide any feedback as to when the buffer size
is going to be exceeded.  This is an MPI problem, and I have some ideas for
fixing it, but not in this release.

Roge


========================================================================

Roger Hillson, PhD		Code 5583
Telephone: 202-404-7332	  	(Advanced Information Technology Branch)
Fax:	   202-767-1122		Naval Research Laboratory
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hillson@ait.nrl.navy.mil	Washington, DC 20375-5337