Ralph, Alas, I will not be at SC16. I would like to hear and/or see what you present, so if it gets made available in alternate format, I'd appreciated know where and how to get it.
I am more and more coming to think that our cluster configuration is essentially designed to frustrated MPI developers because we use the scheduler to create cgroups (once upon a time, cpusets) for subsets of cores on multisocket machines, and I think that invalidates a lot of the assumptions that are getting made by people who want to bind to particular patters. It's our foot, and we have been doing a good job of shooting it. ;-) -- bennet On Fri, Oct 28, 2016 at 7:18 PM, r...@open-mpi.org <r...@open-mpi.org> wrote: > FWIW: I’ll be presenting “Mapping, Ranking, and Binding - Oh My!” at the > OMPI BoF meeting at SC’16, for those who can attend. Will try to explain the > rationale as well as the mechanics of the options > > On Oct 11, 2016, at 8:09 AM, Dave Love <d.l...@liverpool.ac.uk> wrote: > > Gilles Gouaillardet <gil...@rist.or.jp> writes: > > Bennet, > > > my guess is mapping/binding to sockets was deemed the best compromise > from an > > "out of the box" performance point of view. > > > iirc, we did fix some bugs that occured when running under asymmetric > cpusets/cgroups. > > if you still have some issues with the latest Open MPI version (2.0.1) > and the default policy, > > could you please describe them ? > > > I also don't understand why binding to sockets is the right thing to do. > Binding to cores seems the right default to me, and I set that locally, > with instructions about running OpenMP. (Isn't that what other > implementations do, which makes them look better?) > > I think at least numa should be used, rather than socket. Knights > Landing, for instance, is single-socket, so no gets no actual binding by > default. > _______________________________________________ > users mailing list > users@lists.open-mpi.org > https://rfd.newmexicoconsortium.org/mailman/listinfo/users > > > > _______________________________________________ > users mailing list > users@lists.open-mpi.org > https://rfd.newmexicoconsortium.org/mailman/listinfo/users _______________________________________________ users mailing list users@lists.open-mpi.org https://rfd.newmexicoconsortium.org/mailman/listinfo/users
