Open MPI logo

Open MPI Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Development mailing list

From: Troy Benjegerdes (hozer_at_[hidden])
Date: 2005-08-24 21:27:46

On Tue, Aug 16, 2005 at 12:25:32PM -0400, Jeff Squyres wrote:
> Processor affinity is now implemented. You must ask for it via the MCA
> param "mpi_paffinity_alone". If this parameter is set to a nonzero
> value, OMPI will assume that its job is alone on the nodes that it is
> running on, and, if you have not oversubscribed the node, will bind MPI
> processes to processors, starting with processor ID 0 (i.e.,
> effectively bindings MPI processes to the processor number equivalent
> to their relative VPID on that node).
> Please let me know how this works out for everyone; thanks.

Any thoughts on how to support NUMA with something like this? On the
dual opteron w/DDR IB systems I've got, I'm seeing a big perfomance
difference that primarily depends on which node the memory is on.