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Subject: Re: [OMPI users] Any scientific application heavilyusing MPI_Barrier?
From: Joe Landman (landman_at_[hidden])
Date: 2009-03-05 11:24:37


Ralph Castain wrote:

> Ummm....not to put gasoline on the fire, but...if the data exchange is
> blocking, why do you need to call a barrier op first? Just use an
> appropriate blocking data exchange call (collective or whatever) and it
> will "barrier" anyway.

Since I don't run these codes, I would have to defer to those that do.

This said, I am not sure if they are running the coupling as two
separate MPI codes or as one code sharing a communications handle or
whatnot else.

I do agree that letting the data exchange provide a (natural) barrier
makes a great deal of sense, though the codes may not be amenable to
this mode of operations. Gerry could likely shed light on this.

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Joseph Landman, Ph.D
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