I installed Open MPI 1.2.4 in Red Hat Enterprise Linux 3. It worked fine in normal usage. I tested executions with extremely many processes.
$ mpiexec -n 128 --host node0 --mca btl_tcp_if_include eth0 --mca mpool_sm_max_size 2147483647 ./cpi $ mpiexec -n 256 --host node0,node1 --mca btl_tcp_if_include eth0 --mca mpool_sm_max_size 2147483647 ./cpi If I specified the mpiexec options like this, the execution succeeded in both cases. $ mpiexec -n 256 --host node0 --mca btl_tcp_if_include eth0 --mca mpool_sm_max_size 2147483647 ./cpi mpiexec noticed that job rank 0 with PID 0 on node node0 exited on signal 15 (Terminated). 252 additional processes aborted (not shown) $ mpiexec -n 512 --host node0,node1 --mca btl_tcp_if_include eth0 --mca mpool_sm_max_size 2147483647 ./cpi mpiexec noticed that job rank 0 with PID 0 on node node0 exited on signal 15 (Terminated). 505 additional processes aborted (not shown) If I increased the number of processes, the executions aborted. Could I execute 256 processes per node using Open MPI? We would like to execute as large number of processes as possible even if the performance becomes worse. If we use MPICH, we can execute 256 processes per node, but the performance of Open MPI may be better. We understand we must increase the number of open files next because the current implementation uses many sockets. SUSUKITA, Ryutaro Peta-scale System Interconnect Project Fukuoka Industry, Science & Technology Foundation
