Mm, to be sure, if i have one processor who does:
MPI_IBcast(MPI_COMM_WORLD, request_1) // first Bcast MPI_IBcast(MPI_COMM_WORLD, request_2) // second Bcast it means that i can't have another process who does the follow: MPI_IBcast(MPI_COMM_WORLD, request_2) // firt Bcast for another process MPI_IBcast(MPI_COMM_WORLD, request_1) // second Bcast for another process Because first Bcast of second process matches with first Bcast of first process, and it's wrong. Is it right? 2010/9/23 Jeff Squyres <jsquy...@cisco.com> > On Sep 23, 2010, at 6:28 AM, Gabriele Fatigati wrote: > > > i'm studing the interfaces of new collective routines in next MPI-3, and > i've read that new collectives haven't any tag. > > Correct. > > > So all collective operations must follow the ordering rules for > collective calls. > > Also correct. > > > 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 > > No, not quite right. You can have multiple outstanding ibcast's -- they'll > just be satisfied in the same order in all participating MPI processes. > > > 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 > > Correct -- this is also possible. > > More generally, you can have multiple outstanding non-blocking collectives > on a single communicator -- it doesn't matter if they are the same or > different collective operations. They will each be unique instances and will > be satisfied in order. > > -- > Jeff Squyres > jsquy...@cisco.com > For corporate legal information go to: > http://www.cisco.com/web/about/doing_business/legal/cri/ > > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users > > -- 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
