Newsgroups: comp.parallel.pvm
From: wolff@inf.fu-berlin.de (Thomas Wolff)
Subject: Re: PVM under Windows?
Organization: Free University of Berlin, Germany
Date: Wed, 24 Aug 1994 17:21:15 GMT
Message-ID: <Y0VRBY4T@math.fu-berlin.de>

crispin@csd.uwo.ca (Crispin Cowan) writes:

: In article <P7VRBA9Q@math.fu-berlin.de>,
: Thomas Wolff <wolff@inf.fu-berlin.de> wrote:
: >bwh@inf.rl.ac.uk (Brian Henderson) writes:
: >: [PVM on Windows is useless because Windows doesn't do pre-emptive
: multitasking]
: >You are mixing up parallel with distributed computing. Although often 
: >usefully linked together, it's not the same at all. So I think a 
: >system for distribution and communication (which PVM is) can still 

: Actually, I think Thomas is mixing up parallel and distributed
: computing.  PVM is a parallel programming system, layered on top of a
: distributed system (TCP/IP).
The apparently prevailing purpose of PVM is to provide easier means of 
communication between processes running on different machines - this is 
distribution, despite the fact that it uses lower-level systems that 
also provide distribution.

: It's in the name:  PVM == Parallel Virtual Machine.
This is not an argument.

: PVM provides the primitives one expects to see in a
: MPP environment (message passing, array packing, etc.).
Now this is definately distribution, not parallelism.

: PVM does not
: provide many of the facilities needed for a distributed programming
: environment:  resource brokers, multi-user capabilities, security,
: authentication, the ability for an outside task to add itself to the
: system, etc.
These are advanced features not necessarily inherent to a simple 
distributed system. It is one of the very appreciable features that 
PVM lacks much of this fuzz so it can be employed easier for 
systems with simpler requirements.

Thomas Wolff@inf.fu-berlin.de

