Thank you, Gilles. What is the bcast I should look for? In general, how do I know which module was used to for which communication - can I print this info? On Jun 30, 2016 3:19 AM, "Gilles Gouaillardet" <gil...@rist.or.jp> wrote:
> 1) is correct. coll/sm is disqualified if the communicator is an inter > communicator or the communicator spans on several nodes. > > you can have a look at the source code, and you will not that bcast does > not use send/recv. instead, it uses a shared memory, so hopefully, it is > faster than other modules > > > Cheers, > > > Gilles > On 6/30/2016 3:04 PM, Saliya Ekanayake wrote: > > Hi, > > Looking at the *ompi/mca/coll/sm/coll_sm_module.c* it seems this module > will be used only if the calling communicator solely groups processes > within a node. I've got two questions here. > > 1. So is my understanding correct that for something like MPI_COMM_WORLD > where world is multiple processes within a node across many nodes, this > module will not be used? > > 2. If 1, is correct then are there any shared memory optimizations that > happen when a collective like bcast or allreduce is called, so that > communicating within a node is done efficiently through memory? > > Thank you, > Saliya > > > -- > Saliya Ekanayake > Ph.D. Candidate | Research Assistant > School of Informatics and Computing | Digital Science Center > Indiana University, Bloomington > > > > _______________________________________________ > users mailing listus...@open-mpi.org > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users > Link to this post: > http://www.open-mpi.org/community/lists/users/2016/06/29564.php > > > > _______________________________________________ > users mailing list > us...@open-mpi.org > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users > Link to this post: > http://www.open-mpi.org/community/lists/users/2016/06/29565.php >
