-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi folks,
We cater for a mix of single CPU jobs and large MPI jobs and I've just been asked how can someone launch a single MPI rank per *socket* for a hybrid MPI+SMP code. Now we run with: SelectType=select/cons_res SelectTypeParameters=CR_Core,CR_ONE_TASK_PER_CORE because we have to deal with a lot of single CPU jobs. However, the --ntasks-per-socket option is documented as only working with CR_Socket, which says that it will not permit jobs to share sockets. Is there a way to get the socket as a consumable resource but only to have it used when requested, i.e. default to the per-core settings we have? At the moment I've told the user that they can request a whole node and use Open-MPI's 1.6.x binding options thus: [samuel@barcoo ~]$ mpirun --num-sockets 2 --bind-to-socket - --npersocket 1 --display-map numactl --show | fgrep physcpubind physcpubind: 0 1 2 3 4 5 6 7 physcpubind: 0 1 2 3 4 5 6 7 physcpubind: 8 9 10 11 12 13 14 15 physcpubind: 8 9 10 11 12 13 14 15 OMPI 1.7 drops the need to specify how many sockets there are per node with --num-sockets as it'll discover that itself, but getting there from 1.6 to 1.7 is another story. :-) All the best, Chris - -- Christopher Samuel Senior Systems Administrator VLSCI - Victorian Life Sciences Computation Initiative Email: [email protected] Phone: +61 (0)3 903 55545 http://www.vlsci.org.au/ http://twitter.com/vlsci -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlKv2SAACgkQO2KABBYQAh8klACdHJ32hboXTgL9po34DzyngDOI KVsAniZ+8e3s2H4ZnL2wL6bDpwfxqB9A =OmrH -----END PGP SIGNATURE-----
