Thanks, that's what I'm looking for. My first look for documentation is always the FAQ, not the man pages. I found no mention of -npersocket in the FAQ but there it is very clear in the man page. Boy do I feel dumb.
Anyway, thanks a lot. From: users-boun...@open-mpi.org [mailto:users-boun...@open-mpi.org] On Behalf Of Ralph Castain Sent: Thursday, November 08, 2012 10:08 AM To: Open MPI Users Subject: Re: [OMPI users] EXTERNAL: Re: Best way to map MPI processes to sockets? I gather from your other emails you are using 1.4.3, yes? I believe that has npersocket as an option. If so, you could do: mpirun -npersocket 2 -bind-to-socket ... That would put two processes in each socket, bind them to that socket, and rank them in series. So ranks 0-1 would be bound to the first socket, ranks 2-3 to the second. Ralph On Thu, Nov 8, 2012 at 6:52 AM, Blosch, Edwin L <edwin.l.blo...@lmco.com<mailto:edwin.l.blo...@lmco.com>> wrote: Yes it is a Westmere system. Socket L#0 (P#0 CPUModel="Intel(R) Xeon(R) CPU E7- 8870 @ 2.40GHz" CPUType=x86_64) L3Cache L#0 (size=30720KB linesize=64 ways=24) L2Cache L#0 (size=256KB linesize=64 ways=8) L1dCache L#0 (size=32KB linesize=64 ways=8) L1iCache L#0 (size=32KB linesize=64 ways=4) Core L#0 (P#0) PU L#0 (P#0) L2Cache L#1 (size=256KB linesize=64 ways=8) L1dCache L#1 (size=32KB linesize=64 ways=8) L1iCache L#1 (size=32KB linesize=64 ways=4) Core L#1 (P#1) PU L#1 (P#1) So I guess each core has its own L1 and L2 caches. Maybe I shouldn't care where or if the MPI processes are bound within a socket; if I can test it, that will be good enough for me. So my initial question is now changed to: What is the best/easiest way to get this mapping? Rankfile?, --cpus-per-proc 2 --bind-to-socket, or something else? RANK SOCKET CORE 0 0 unspecified 1 0 unspecified 2 1 unspecified 3 1 unspecified Thanks -----Original Message----- From: users-boun...@open-mpi.org<mailto:users-boun...@open-mpi.org> [mailto:users-boun...@open-mpi.org<mailto:users-boun...@open-mpi.org>] On Behalf Of Brice Goglin Sent: Wednesday, November 07, 2012 6:17 PM To: us...@open-mpi.org<mailto:us...@open-mpi.org> Subject: EXTERNAL: Re: [OMPI users] Best way to map MPI processes to sockets? What processor and kernel is this? (see /proc/cpuinfo, or run "lstopo -v" and look for attributes on the Socket line) You're hwloc output looks like an Intel Xeon Westmere-EX (E7-48xx or E7-88xx). The likwid output is likely wrong (maybe confused by the fact that hardware threads are disabled). Brice _______________________________________________ users mailing list us...@open-mpi.org<mailto:us...@open-mpi.org> http://www.open-mpi.org/mailman/listinfo.cgi/users
