At 21:00 16.01.2008, Greg Lindahl <[EMAIL PROTECTED]> wrote:
Use an MPI which does this for you? Two examples are InfiniPath MPI and OpenMPI.
.. and another is Scali MPI Connect. We do it in two dimensions; latency or bandwidth policy, that is to use as few or many sockets as possible. Once that is selected, the resolution can be defined as a hyperthread, core (all HTs constituting a core), socket (all cores constituting a socket), or a node (all sockets on a node).
The resolution is important for hybrid application; on a dual-socket, quad-core system, you can specify bandwidth policy and socket resolution staring two MPI processes. The first rank will be bound to all the cores on the first socket, the second on all the cores on the other socket.
Further, the decision on which cores/sockets to use is determined dynamically, so multiple MPI instances on the same node is supported.
Thanks, Hakon _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
