[Beowulf] OpenMP on AMD dual core processors

Greg Lindahl lindahl at pbm.com
Fri Nov 21 12:16:18 PST 2008

On Fri, Nov 21, 2008 at 09:38:29AM -0600, Nathan Moore wrote:

> I had a similar problem with gfortran, and it only appeared with large array
> sizes (bigger than 4000x4000 as I recall).  "ulimit" was no help, I assume
> there's a memory constraint built in somewhere.

With OpenMP the compiler has to set up multiple stacks, and some are
more clever than others. If you were using the PathScale compiler, for
example, and overran one of the thread stacks, it would print out an
error message saying what happened and how to raise that limit.

gfortran's omp probably has documentation which discusses how to raise
the stack limit. It's not a simple ulimit...

-- greg

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