On 04-01-2013 18:28, Ralph Castain wrote: > FWIW: I believe we have a mapper in Open MPI that does what you want - i.e., > it looks at the number of available cpus on each node, and maps the processes > to maximize the number of procs co-located on nodes. In your described case, > it would tend to favor the 16ppn nodes as that would provide the best MPI > performance, then move to the 8ppn nodes, etc.
Yes, OpenMPI can be tweaked into different task layouts on the available set of nodes. But the problem at hand is for the scheduler to allocate some set of nodes, given that the user want a specific number of MPI tasks (say, 32), and given that there are heterogeneous nodes available with 4, 8 or 16 cores. As Moe wrote, this flexibility would be hard to achieve with Slurm (with Maui it's impossible). Regards, Ole
