On Feb 27, 2012, at 4:42 AM, Paul Kapinos wrote: > Dear Open MPI developer, > here: > http://www.open-mpi.org/faq/?category=running#mpi-environmental-variables > are enlisted four envvars Open MPI set for every process. We use they for > some scripting and thank you for providing they. > > But simple "mpiexec -np 1 env | grep OMPI" brings lotz more enviers.
Yes, we set quite a few more, but those are intended solely for internal use and are not guaranteed. The list on the web site only identifies a set that are guaranteed to be provided. > These are interesting for us: > > 1) OMPI_COMM_WORLD_LOCAL_SIZE - seem to contain the number of processes which > are running on the specific node, see also > http://www.open-mpi.org/community/lists/users/2008/07/6054.php > > Is this envvar also "stable" as OMPI_COMM_WORLD_LOCAL_RANK is? (This would > make sense as it looks like the OMPI_COMM_WORLD_SIZE, OMPI_COMM_WORLD_RANK > pair.) Yes, and I'll add it to the page > > If yes, maybe it also should be documented in the Wiki page. > > > > 2) OMPI_COMM_WORLD_NODE_RANK - is that just a double of > OMPI_COMM_WORLD_LOCAL_RANK ? No - the "local rank" is your rank on the node within your own job. The "node rank" is your rank on the node overall. The two differ when you do a comm_spawn. For example, suppose you have two ranks from your initial job on a node, and then comm_spawn three additional ranks. Their values would look like this: job/rank local_rank node_rank 0/0 0 0 0/1 1 1 1/0 0 2 1/1 1 3 1/2 2 4 Again, I'll add it to the page Thanks Ralph > > Best wishes, > Paul Kapinos > > > > -- > Dipl.-Inform. Paul Kapinos - High Performance Computing, > RWTH Aachen University, Center for Computing and Communication > Seffenter Weg 23, D 52074 Aachen (Germany) > Tel: +49 241/80-24915 > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users
