Newsgroups: comp.parallel.mpi
From: werner@visaw.rus.uni-stuttgart.de (Andreas Werner)
Subject: Re: So what is ch_p4?
Organization: Comp.Center (RUS), U of Stuttgart, FRG
Date: 5 Sep 1995 15:48:35 GMT
Message-ID: <42hrgj$o1a@info4.rus.uni-stuttgart.de>

In article <423fl3$r56@hearst.cac.psu.edu>, Mike Yukish  <yukish> wrote:
>What is the ch_p4 that is the device? I am trying to install the MPI libraries
>on a Sun4 and an sgi, and I don't recognize the term. Is it something else
>that I have to add to the computers?

Just ported to SGI:

ch_p4 is an internal lib (you need not care for it, it is built by
the makefile) that is responsible foe the communication via sockets.

If you are using multiprocessor systems you should use the ch_shmem
device, which uses shared memory for communication.

If possible, build your MPI directly in /usr/local/mpi. If you use
-prefix=PREFIXDIR, do 'ln -s PREFIXDIR/util PREFIXDIR/bin' before
'make install' or you will run into some trouble. This is an known
bug.

By the way: On the MPI WWW server you will find a patch to speed up
socket communication on SGI's.

Andreas
---
Andreas Werner              | Institute for Computer Applications II
werner@rus.uni-stuttgart.de | Computer Simulation and Visualization
Tel.: ++49-(0)711-685-5790  | University of Stuttgart - Computer Center
Fax:  ++49-(0)711-678-7626  | Allmandring 30  D-70550 Stuttgart  Germany

