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Subject: [OMPI users] help: seg fault when freeing communicator
From: Graham Mark (gam_at_[hidden])
Date: 2009-04-13 10:01:32

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

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

Thanks for your help.

Graham Mark

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Graham Mark
Information Sciences
Los Alamos National Laboratory