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Subject: Re: [OMPI users] help: seg fault when freeing communicator
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2009-04-14 10:53:46

In this case, I think we would need a little more information such as
your application itself. Is there any chance you can make a small
reproducer of the application that we can easily study and reproduce
the problem?

Have you tried running your application through a memory-checking
debugger, perchance?

On Apr 13, 2009, at 10:01 AM, Graham Mark wrote:

> This has me stumped. My code seg faults (sometimes) while
> it's attempting to free a communicator--at least, that's what the
> stack trace indicates, and that's what Totalview also shows.
> This happens when I run the program with 27 processes. If I run with
> 8,
> the program finishes without error. (The program requires that the
> number of
> processes be a perfect cube.) It happens on two different machines.
> The program reads input files and creates a 1-D circular MPI topology
> in order to pass input data round robin to all processes. When that is
> done, each process does some computation and writes out a file. Then
> the program finishes. The seg fault occurs when the communicator
> associated with the topoology is supposedly being freed as the program
> ends.
> The openmpi help web page lists information that should be included in
> a help request. I'm attaching all of that that I could find: my
> command to run the program, the stack trace, the outputs of
> 'ompi_info', 'limit', 'ibv_devinfo', 'ifconfig', 'uname' and values of
> my
> Thanks for your help.
> Graham Mark
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Jeff Squyres
Cisco Systems