[mpich-devel] MPI_Comm_split_type extensions

[Rob Latham]

On 11/19/2015 03:01 PM, Jeff Hammond wrote:
> That is so cool!  Do you have psychic powers or did you actually go from
> email to finished code in 65 minutes?

Pavan maybe has the psychic powers?  he asked  me work on this a couple 
months ago.

but the two implementations have made interesting design choice: 
OpenMPI went with the "add a lot of flags" approach.  Pavan suggested we 
take an approach that introduces only one new flag 
(MPIX_COMM_SPLIT_NEIGHBORHOOD) but then uses an info argument to 
indicate *how* that neighborhood split should occur.

As far as an implementation is concerned, both approaches are equivalent.

As an end-user, Jeff, do you have an opinion (hah! oh, I kill me... I 
thought I could type that with a straight face, I really did...) on 
which approach you prefer?

==rob

> Jeff
>
> On Thu, Nov 19, 2015 at 12:39 PM, Rob Latham <robl at mcs.anl.gov
> <mailto:robl at mcs.anl.gov>> wrote:
>
>
>
>     On 11/19/2015 01:34 PM, Jeff Hammond wrote:
>
>         https://github.com/open-mpi/ompi/pull/320 implements features
>         related to
>         what was proposed in
>         https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/297 and
>         https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/372.
>
>         It would be nice if MPICH supported such things as well.  Since
>         MPICH
>         also uses HWLOC, I imagine it is not too difficult.
>
>         I will file a ticket about this in the absence of objections.
>
>
>
>     BLAMMO!
>
>     http://git.mpich.org/mpich-dev.git/shortlog/refs/heads/comsplit_commonfs
>
>     ==rob
>
>
>         Thanks,
>
>         Jeff
>
>         --
>         Jeff Hammond
>         jeff.science at gmail.com <mailto:jeff.science at gmail.com>
>         <mailto:jeff.science at gmail.com <mailto:jeff.science at gmail.com>>
>         http://jeffhammond.github.io/
>
>
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>     --
>     Rob Latham
>     Mathematics and Computer Science Division
>     Argonne National Lab, IL USA
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>
> --
> Jeff Hammond
> jeff.science at gmail.com <mailto:jeff.science at gmail.com>
> http://jeffhammond.github.io/
>
>
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-- 
Rob Latham
Mathematics and Computer Science Division
Argonne National Lab, IL USA