[mpi3-coll] Our MPI-2.2 items

Jesper Larsson Traeff traff at it.neclab.eu
Tue Jul 29 03:47:42 CDT 2008


Hello everybody,

On Mon, Jul 28, 2008 at 02:17:50PM -0400, Torsten Hoefler wrote:
> Hello Collectives Workgroup,
> I just added our open MPI-2.2 items to the list. 
>
good. I'll try to add something, too:

MPI_Reduce_scatter_block
Extended binary reduction operators for segmented scans
Clarification on intercomm Barrier
 
> Please review items 13-16 on
> https://svn.mpi-forum.org/trac/mpi-forum-web/wiki/MpiTwoTwoWikiPage
> 
> The deadline for things to be considered for MPI-2.2 is next Friday.
>
uuh - well...
 
> I dropped the partial pack/unpack from our list of open issues because
> large datatypes can be disassembled via query functions and thus packed
> in pieces with MPI_TYPE_GET_ENVELOPE and MPI_TYPE_GET_CONTENTS.
>
I disagree with this argument. While it is possible, it leaves completely
to the user (in this case: high-level library implementer) to implement
these pack/unpack functions efficiently, and this is not a trivial
task at all

I have been hesitant in posting a concrete proposal because the exposed
partial packing functions should also make sense in a heterogeneous
environment, and I'm not sure how to handle this (I'm not even sure
MPI_Pack/Unpack do...)

Thus: I'll try to post something this week... at least, we should discuss
about this at the teleconf.

> Please add any missing items and/or corrections to the wiki and/or feel
> free to discuss them on the list.
> 
I think your fixes to the topology interface needs more

Thanks, and best regards

Jesper




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