Jeff I would perhaps remember your statement like part of a religious scripture!
Request to you and everyone else: if you know of a good book and/or online tutorial on 'how to write large parallel scientific programs', I am sure it would be of immense use to everyone in this list. Best regards Durga On Thu, Mar 5, 2009 at 10:25 AM, Jeff Squyres <jsquy...@cisco.com> wrote: > On Mar 5, 2009, at 9:29 AM, Shanyuan Gao wrote: > >> I am doing some research on MPI barrier operations. And I am ready >> to do some performance test. >> I wonder if there are any applications that using barriers a lot. >> Please let me know if there >> is any. Any comments are welcomed. Thanks! >> > > > I don't remember who originally said it, but I've repeated the statement: > any MPI program that relies on a barrier for correctness is an incorrect MPI > application. > > There's anecdotal evidence that throwing in a barrier every once in a while > can help reduce unexpected messages (and other things), and therefore > improve performance a bit. But that's very application dependent, and > usually not frequent. > > Why do you want to do a barrier? Particularly one that sounds like it might > be in your critical performance path? > > -- > Jeff Squyres > Cisco Systems > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
