Newsgroups: comp.parallel.mpi
From: cattoni@irst.it (Roldano Cattoni)
Subject: MPICH with shared memory and Tcp/IP
Organization: Istituto Trentino di Cultura - IRST
Date: 16 Dec 1995 13:27:37 GMT
Message-ID: <4auhg9$j6q@wonder.itc.it>

I installed MPICH 1.00.11. on a network of workstations (solaris, hpux and
LINUX).

I compiled it with the ch_p4 device without local shared memory:
I would like to improve performance using shared memory communication when
possible.

So I tried to re-compile MPICH in order to use shared memory for processes
on the same machines and  Tcp/IP socket for the other connections. This
correspond to be allowed to use a p4 file with lines like
	local 5  <executable_for_local_host>
	host1 6  <executable_for_host1>
        ...

I didn't manage it!

I followed 2 roads:
1. I configured (for example) the hpux with -device=ch_shmem:
   it worked but only with hpux: no p4 program file admitted!
   (I want to use it for my network of eterogeneous workstations).

2. Following the instructions I configure the hpux with the options
   options -device=ch_p4 -comm=shared -arch=hpux 
   It didn't work:
   I get always the message " p4_error: more slaves than msg queues"
   (no shared memory allowed!)
   I debugged the configure program and found that at the end of
   its processing the COMM variable is forced to the (normal) ch_p4:
   I tried to force in all the Makefile's "COMM=shared"
   but the result is the same: no shared mempry allowed!


Any suggestion?

Many thanks in advance!

	Roldano Cattoni


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