Path: utzoo!attcan!uunet!ncrlnk!ncr-sd!hp-sdd!hplabs!ucbvax!tut.cis.ohio-state.edu!unmvax!gatech!hubcap!midkiff
From: midkiff@uicsrd.csrd.uiuc.edu (Sam Midkiff)
Newsgroups: comp.parallel
Subject: Re: Opinions on Debugging Parallel Programs
Message-ID: <4830@hubcap.UUCP>
Date: 17 Mar 89 22:09:49 GMT
Sender: fpst@hubcap.UUCP
Lines: 28
Approved: parallel@hubcap.clemson.edu

>
>I think a useful tool would be something that captured the order
>of "events" to make a MIMD program have a repeatable order of
>execution.  When I am debugging I want a deterministic sequence
>of events.  For example, I want processes to finish tasks in the same order.
>I believe something like this was being worked on at U. Rochester.
>I think that one of the people involved was Tom LeBlanc if you
>want to check into it.  It was being developed on their 128 node butterfly.
>Anyone know the status of this?
>

Todd Allen and Sanjoy Ghosh, with Profs. David Padua and Perry Emrath at CSRD, 
U of Illinois have been working on a system which captures potential dependence
violations and allows them to be analyzed after the program execution.  Existing
synchronization is taken into account to reduce the amount of trace information
needed for the post-execution analyses.  Two papers covering this work are:


Todd R. Allen and David Padua, "Debugging Parallel Fortran on a Shared Memory 
Machine", Proc. of 1987 Int'l. Conf. on Parallel Processing, St. Charles, IL,
pages 721-727. 

Perry Emrath and Sanjoy Ghosh and David Padua, "Event Synchronization Analysis 
for Debugging Parallel Programs", Subm. for publ. to 1989 Int'l. Conf. on 
Parallel Processing, St. Charles, IL

Both are also CSRD tech reports.  The authors can be reached at CSRD, 104 S 
Wright St., 305 Talbot Lab, U of Il., Urbana, IL., 61802