It sounds like you just want to bind procs to cores since each core is composed of 2 HTs. So a simple “--map-by core --bind-to core" should do the trick.
FWIW: the affinity settings are controlled by the bind-to <foo> option. You can use “mpirun -h” to get the list of supported options and a little explanation: --bind-to <foo> Bind processes to the specified object, defaults to core. Supported options include slot, hwthread, core, l1cache, l2cache, l3cache, socket, numa, board, and none. https://www.open-mpi.org/doc/current/man1/mpirun.1.php#sect9 <https://www.open-mpi.org/doc/current/man1/mpirun.1.php#sect9> > On Jul 17, 2016, at 11:25 PM, John Hearns <hear...@googlemail.com> wrote: > > Please can someone point me towards the affinity settings for: > OpenMPI 1.10 used with Slurm version 15 > > I have some nodes with 2630-v4 processors. > So 10 cores per socket / 20 hyperthreads > Hyperthreading is enabled. > I would like to set affinity for 20 processes per node, > so that the processes are pinned to every second HT core - ie one process per > physical thread. > > I'm sure this is quite easy... > > Thankyou > _______________________________________________ > 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/2016/07/29674.php