Subject: Re: [MPI #2000] MPI related Problems on SMPs

From: Rusty Lusk <[email-masked]>
Date: Mon, 07 Oct 1996 22:49:26 -0500

| 	MPI : MPICH version 1.12 over p4 (tcp/ip) 
| 

You should get 1.0.13 and apply the patches available at
http://www.mcs.anl.gov/mpi/mpich (get the big patch)

| 	Configuration option: -arch=solaris -device=ch_p4 -comm=shared
| 

We have not extensively testing this configuration with solaris but it should
work. 

| 
| Questions:
| 	1. What is the suitable programming model for  our architecture with MPIlike SIMD,MIMD..

MPI provides access to the message-passing model.  The shared memory will be
used to provide fast message passing within a machine.

| 	2. How do we place the tasks for SIMD or MIMD 
| 	eg; in the pg file

You should read the sections on this in the User's Manual in the doc directory.

| 	3. Our MPI v1.12 with -comm=shared has been configured on a 8 node Ultra2s and with SIMD code ( all same executables ) it goes through , but with MIMD code ( different executables sharing memory ) it does'nt work , Why?

To get shared memory, you must fork, thus getting multiple copies of the same
executable.

| 	4. Is there any other MPI version specific for SMPs or any other configuration option to be done for MPICH
| 

You can use your configuration without the -comm=shared option, getting
sockets for all communication.