Le 13/09/2011 18:59, Peter Kjellström a écrit : > On Tuesday, September 13, 2011 09:07:32 AM nn3003 wrote: >> Hello ! >> >> I am running wrf model on 4x AMD 6172 which is 12 core CPU. I use OpenMPI >> 1.4.3 and libgomp 4.3.4. I have binaries compiled for shared-memory and >> distributed-memory (OpenMP and OpenMPI) I use following command >> mpirun -np 4 --cpus-per-proc 6 --report-bindings --bysocket wrf.exe >> It works ok and in top i see there are 4 wrf.exe and each has 6 threads on >> cpu0-5 12-17 24-29 36-41 However, if I want to run 8 or more e.g. >> mpirun -np 4 --cpus-per-proc 12 --report-bindings --bysocket wrf.exe >> I get error >> Your job has requested more cpus per process(rank) than there >> are cpus in a socket: >> Cpus/rank: 8 >> #cpus/socket: 6 >> >> Why is that ? There are 12 cores per socket in AMD 6172. > In reality a 12 core Magnycours is two 6 core dies on a socket. I'm guessing > that the topology code sees your 4x 12 core as a 8x 6 core.
plpa-info reports 4*6cores: Number of processor sockets: 4 Number of processors online: 48 Number of processors offline: 0 (no topology information available) Socket 0 (ID 0): 6 cores (max core ID: 5) Socket 1 (ID 1): 6 cores (max core ID: 5) Socket 2 (ID 2): 6 cores (max core ID: 5) Socket 3 (ID 3): 6 cores (max core ID: 5) This should be fixed with Open MPI 1.5.2+ with hwloc. Brice
