On Apr 24, 2012, at 3:01 PM, Tom Rosmond wrote:

> My question is this:  If the cartesian mapping is done so the two
> spacial dimensions are the 'most rapidly varying' in equivalent 1-D
> processor mapping, will Open-mpi automatically assign those 2 dimensions
> 'on-node', and assign the 'ensemble' dimension as the slowest varying
> and across nodes?  If not, how can we guarantee this to happen?


Sadly, the MPI mapping functions in Open MPI are effectively no-ops -- if you 
ask for re-ordering, OMPI says "sure!" but then gives you back exactly the same 
mapping.  :-(

That being said, the mapping functionality is actually a plugin in Open MPI (in 
the "topo" framework).  It would not be too difficult to write a plugin for the 
mapping that you want.

Would this be of interest to you?  I'd be happy to talk you through the process 
of writing such a plugin.

-- 
Jeff Squyres
jsquy...@cisco.com
For corporate legal information go to: 
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