In the OMPI v1.6 series, you can use the processor affinity options. And you can use --report-bindings to show exactly where processes were bound. For example:
----- % mpirun -np 4 --bind-to-core --report-bindings -bycore uptime [svbu-mpi056:18904] MCW rank 0 bound to socket 0[core 0]: [B . . .][. . . .] [svbu-mpi056:18904] MCW rank 1 bound to socket 0[core 1]: [. B . .][. . . .] [svbu-mpi056:18904] MCW rank 2 bound to socket 0[core 2]: [. . B .][. . . .] [svbu-mpi056:18904] MCW rank 3 bound to socket 0[core 3]: [. . . B][. . . .] 05:06:13 up 7 days, 6:57, 1 user, load average: 0.29, 0.10, 0.03 05:06:13 up 7 days, 6:57, 1 user, load average: 0.29, 0.10, 0.03 05:06:13 up 7 days, 6:57, 1 user, load average: 0.29, 0.10, 0.03 05:06:13 up 7 days, 6:57, 1 user, load average: 0.29, 0.10, 0.03 % ----- I bound each process to a single core, and mapped them on a round-robin basis by core. Hence, all 4 processes ended up on their own cores on a single processor socket. The --report-bindings output shows that this particular machine has 2 sockets, each with 4 cores. On Aug 30, 2012, at 5:37 AM, Zbigniew Koza wrote: > Hi, > > consider this specification: > > "Curie fat consists in 360 nodes which contains 4 eight cores CPU Nehalem-EX > clocked at 2.27 GHz, let 32 cores / node and 11520 cores for the full fat > configuration" > > Suppose I would like to run some performance tests just on a single processor > rather than 4 of them. > Is there a way to do this? > I'm afraid specifying that I need 1 cluster node with 8 MPI prcesses > will result in OS distributing these 8 processes among 4 > processors forming the node, and this is not what I'm after. > > Z Koza > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
