In reply to Heiko.

Heiko:

With respect to "when MPI implementations allow threading on the level of MPI_THREAD_MULTIPLE," many implementations support this. It is just that Open MPI does not. MPICH and its derivatives - MVAPICH2, Intel MPI, Cray MPI, etc. - have supported MPI_THREAD_MULTIPLE for many years. I use it all the time.

Granted, there may be performance issues [http://www.mcs.anl.gov/~balaji/pubs/2015/ppopp/ppopp15.mpi_threads.pdf] but they are not intractable (e.g. http://dx.doi.org/10.1109/IPDPS.2012.73 and http://sc15.supercomputing.org/schedule/event_detail?evid=pap145).

Please try MPICH or a derivative thereof next time you want full support for MPI-3 and send Jeff Squyres a note once a week to inquire about the status of https://github.com/open-mpi/ompi/issues/157 :-)

Best,

Jeff