Hi, I would like to divide n processes between the sockets on a node, with one process per core, and bind them to a hwthread. Consider a system with 2 sockets, 10 cores per socket, and 2 hwthreads per core. If I enter
-np 20 --map-by ppr:1:core --bind-to hwthread then this works as I intend. But if I only want 10 processes with 5 on each socket, then -np 10 --map-by ppr:5:socket --bind-to hwthread will map two processes to each core (1 per hwthread). I also tried -np 10 --map-by ppr:5:socket:pe=2 --bind-to hwthread -np 10 --map-by ppr:5:socket --bind-to core but both of those will bind to the core. How can I say 5 per socket and only 1 per core and bind to a single hardware thread? I am using openmpi 1.8.8. Thanks, Stephen
