Newsgroups: comp.parallel.mpi
From: eddemain@neumann.uwaterloo.ca (Erik Demaine)
Subject: Efficient pseudo-parallelism in MPI
Organization: University of Waterloo
Date: Thu, 30 May 1996 16:52:58 GMT
Message-ID: <Ds89KA.A9p@undergrad.math.uwaterloo.ca>

G'day,

I am curious if there exists an MPI implementation that does *not* use
UNIX's processes to simulate parallelism, i.e., provide concurrency.  In
other words, is there one that uses custom multitheading to achieve extremely
fast context switching and low OS overhead?  This would be particularly
useful for debugging and testing with a high degree of parallelism.

A while ago I heard of a similar project with PVM.  The posting is enclosed
below.

Erik
--
Erik Demaine                 \/  e-mail: eddemain@neumann.uwaterloo.ca
Dept. of Computer Science    /\  URL   : http://barrow.uwaterloo.ca/~eddemain/
University of Waterloo       \/  Most jugglers do poorly while drunk, especially
Waterloo, ON Canada N2L 3G1  /\  in a large wavelength gravity field.
-------------------------------- CUT HERE -------------------------------- 
From: Manuel Mollar Villanueva <mollar@moon.inf.uji.es>
Newsgroups: comp.parallel.pvm
Subject: PVM for DOS and more
Date: Mon, 12 Feb 1996 17:47:34 +0100
Organization: Departamento de Informatica - Univ. Jaume I
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I have implemented the PVM3 using ansi C.
So, it can be compiled under any operating system that has an ansi C compiler.
The package is intended only for program developement.
Multitasking is simulated.
It has several limitations compared to the UNIX standard.
Several properties:
  - A lot of processes can be simulated (in my Linux machine, 50000 without
                problem).   [Erik's note: 50,000 is very impressive!  This
			     is pretty much impossible using UNIX multitasking.]
  - It is fast.
  - It is small (distribution file: 47 k).
  - Task are auto-synchronized.
  - Debugging of n tasks in a single window.
I have tested it under DOS, unsing Borland C 3.1, and under Linux, IRIX and
HP/UX.
You can obtain it via ftp from:
   moon.inf.uji.es
directory:
  pub/parallel
files:
  pvm3ansi.DOS-BC31.exe         (auto-extraction)
  pvm3ansi.linux.tar.gz
For more information, contact with the author via e-mail, mollar@inf.uji.es
Enjoy-it.


