Path: utzoo!attcan!uunet!cs.utexas.edu!asuvax!ncar!tank!ux1.cso.uiuc.edu!ravel.csg.uiuc.edu!blj
From: blj@ravel.csg.uiuc.edu (Bob Janssens)
Newsgroups: comp.sys.encore
Subject: barrier synchronization
Message-ID: <1989Dec17.215151.17792@ux1.cso.uiuc.edu>
Date: 17 Dec 89 21:51:51 GMT
Sender: news@ux1.cso.uiuc.edu (News)
Reply-To: blj@ravel.csg.uiuc.edu.UUCP (Bob Janssens)
Organization: Univ of Illinois at Urbana-Champaign
Lines: 15

We are running UMAX-4.2 R3.3.0 on our 8 processor Multimax 510.  I am having
some trouble with the barrier synchronization.  About 20% of the time my
simple gaussian elimination program deadlocks at one of the barriers.
However, print statements show that every process reaches the barrier.  I
have tried the fbarrier and the regular barrier with all three types of
blocking, and get similar results with all.  I also have an account on the
Argonne National labs encore which is running the beta version of UMAX-4.3.
Here my program runs fine without any deadlock.  Other users on our system
have had similar problems with parallel programming.  Could this be a 
problem with our OS?  Have other people had similar problems?

Thanks,
Bob Janssens				b-janssens@uiuc.edu
Center for Reliable and 
High Performance Computing