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Subject: Re: [OMPI users] Any scientific application heavilyusing MPI_Barrier?
From: Eugene Loh (Eugene.Loh_at_[hidden])
Date: 2009-03-05 11:38:00


Jeff Squyres wrote:

> If you're exchanging data at the end of an iteration, then you
> effectively have a synchronization anyway -- no need for an extra
> barrier synchronization.

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.

I could also imagine processes interacting/communicating/whatever via
some other mechanism than MPI calls. Heck, OMPI itself is an example.
Maybe they interact via a file system or something.

Anyhow, I agree with the majority sentiment: single raised eyebrow if
there's an app that beats heavily on Barrier.