Newsgroups: comp.parallel
From: shubu@cs.wisc.edu (Shubu Mukherjee)
Subject: comparative study of irregular problems on three s/w platforms
Organization: CS Department, University of Wisconsin
Date: 03 Apr 1995 13:33:38 GMT
Message-ID: <3lrkhc$amg@usenet.srv.cis.pitt.edu>

Efficient Support for Irregular Applications on Distributed-Memory
			Machines

	  Shubhendu S. Mukherjee, Shamik D. Sharma, 
   Mark D. Hill, James R. Larus, Anne Rogers, and Joel Saltz.

To Appear in the Proceedings of the Fifth ACM SIGPLAN Symposium on
Principles and Practices of Parallel Programming (PPoPP), July 1995.

This paper is now available from:

ftp://ftp.cs.wisc.edu:/wwt/ppopp95_irregular.ps and
http://www.cs.wisc.edu/~wwt/wwt_papers.html#tempest. 

This is a joint work between the Wisconsin Wind Tunnel project
(http://www.cs.wisc.edu/~wwt) at the University of Wisconsin-Madison
and the CHAOS project (http://www.cs.umd.edu/projects/hpsl.html) at
the University of Maryland, College Park. 

Abstract
--------
Irregular computation problems underlie many important scientific
applications.  Although these problems are computationally expensive,
and so would seem appropriate for parallel machines, their irregular
and unpredictable run-time behavior makes this type of parallel
program difficult to write and adversely affects run-time performance.

This paper explores three issues---partitioning, mutual exclusion, and
data transfer---crucial to the efficient execution of irregular
problems on distributed-memory machines.  Unlike previous work, we
studied the same programs running in three alternative systems on the
same hardware base (a Thinking Machines CM-5): the CHAOS irregular
application library, Transparent Shared Memory (TSM), and eXtensible
Shared Memory (XSM).  CHAOS and XSM performed equivalently for all
three applications.  Both systems were somewhat (13\%) to
significantly faster (991\%) than TSM.

--
Shubu Mukherjee        University of Wisconsin-Madison, Computer Sciences

