[mpi3-coll] Neighborhood collectives round 2: reductions

[Torsten Hoefler]

Hi all,

We discussed the neighborhood reductions at the last Forum and the straw
vote if we should include them in the next revision was:

 - yes: 18
 - no: 0
 - abstain: 3

I addressed all the issues in the draft that were brought up at the
Forum. The new draft is now at http://www.unixer.de/sec/topol.pdf . Look
for ticket "XXX". 

One open question remains: would a single send buffer for
neighbor_reduce suffice or do we need one buffer per destination
process? The second case could always be done with neighbor_reducev
(with small additional costs). This questions is more to the potential
users (Jed etc.).

Please check the document and discuss any comments on the mailinglist!

Thanks & Best,
  Torsten

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Torsten Hoefler           | Assistant Professor
Dept. of Computer Science | ETH Zürich
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