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Subject: [OMPI users] Question about Asynchronous collectives
From: Gabriele Fatigati (g.fatigati_at_[hidden])
Date: 2010-09-23 06:28:32


Dear all,

i'm studing the interfaces of new collective routines in next MPI-3, and
i've read that new collectives haven't any tag.

So all collective operations must follow the ordering rules for collective
calls.

>From what i understand, this means that i can't use:

MPI_IBcast(MPI_COMM_WORLD, request_1) // first Bcast
MPI_IBcast(MPI_COMM_WORLD, request_2) // second Bcast

but is it possible to do this:

MPI_IBcast(MPI_COMM_WORLD, request_1) // first Bcast
MPI_IReducet(MPI_COMM_WORLD, request_2) // othwer collective

In other words, i can't overlap the same collective more time on one
communicator, but is it possible with different collectives?

Thanks a lot.

-- 
Ing. Gabriele Fatigati
Parallel programmer
CINECA Systems & Tecnologies Department
Supercomputing Group
Via Magnanelli 6/3, Casalecchio di Reno (BO) Italy
www.cineca.it                    Tel:   +39 051 6171722
g.fatigati [AT] cineca.it