2016-03-13 23:04 GMT+01:00 Matthew Larkin <lar...@yahoo.com>: > Thanks Nick, > > I do understand they are different parallel paradigms and I understand the > purpose of each. > > If I run mpi processes to exhaust all cores, what is the need or purpose to > also use openmp to create threads? I believe there will be no resources left > for the forked threads? No, in that case there is no need to create forked threads. However, if you know that your threading performs better at a certain level of MPI parallelisation you may instead of increasing MPI processors increase threads. For instance, instead of launching 8 MPI processors you may launch 2 MPI processors each forking 4 threads.
> > Sent from Yahoo Mail on Android > > On Sun, Mar 13, 2016 at 5:59 PM, Nick Papior > <nickpap...@gmail.com> wrote: > 2016-03-13 22:02 GMT+01:00 Matthew Larkin <lar...@yahoo.com>: >> Hello, >> >> My understanding is Open MPI can utilize shared and/or distributed memory >> architecture (parallel programming model). OpenMP is soley for shared >> memory >> systems. >> >> I believe Open MPI incorporates OpenMP from some of the other archives I >> glanced at. > This is not true. >> >> Is this a true statement? If so, is there any need to create a hybrid >> model >> that uses both OpenMP and Open MPI? > Sure there is, they are two different parallel paradigms. > Basically MPI is distributed while OpenMP is shared. > Try reading about OpenMP on wiki and/or MPI on wiki: > OpenMP: > https://en.wikipedia.org/wiki/OpenMP > MPI: > https://en.wikipedia.org/wiki/Message_Passing_Interface > >> >> Thanks! > >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users >> Link to this post: >> http://www.open-mpi.org/community/lists/users/2016/03/28696.php > > > > -- > Kind regards Nick > -- Kind regards Nick
