[mpi3-coll] Design issues/possibilities for Sparse Collectives

[Jesper Larsson Traeff]

Dear coll WG,

Torsten and I have tried to write up more systematically some of the issues 
and possibilities that arise in the design of sparse collectives
for MPI, and made a concrete proposal for a small set of sparse collectives.

We hope this will generate some serious discussion; all sorts of comments, 
suggestions, criticisms of course most welcome. Leaving aside improvements 
and changes to the interface, the more interesting question to the Forum is 
of course whether this kind of functionality helps enough users and/or 
library builders enough that it should be included in a future MPI standard

The discussion/proposal has been put on the Wiki, Collectives WG under
III. Sparse/Topological collectives

best regards

Jesper