Andrew Lumsdaine, Andrew.Lumsdaine@nd.edu
Tony Skjellum (chair), tony@cs.msstate.edu
Arkady Kanevsky, arkady@mitre.org
but still considerable discussion and progress was made.
(Steve Huss-Lederman made an appearance as well.)
In the plenary session, the chair was advised to organize the chapter
carefully so that options can be voted on with clarity by July meeting.
Strategy:
* First reading at July meeting
* Revised chapter to be made available by June 21, with revisions to that
by July 5
Threads Recommendation:
-----------------------
The threads discussion in the current chapter should be merged with the Miscellany
chapter. Since so much depends on the collective issues, we wish to subsume that
material, if it is not going into a separate chapter by the July meeting.
Handout was made at the plenary session, which constitutes the language bindings
for the intercommunicator collectives, and also additional intra-communicator
manipulation functions for topologies. This will appear in the next chapter release.
Exclusive scan
--------------
The subcommittee devised an exclusive scan operation, in order to try to bring
functionality inclusions to a completion at the June meeting, with finalization
of the posed functionality to occur during the remainder of the MPI-2 forum
meetings (including readings).
MPI_EXSCAN(sbuf,rbuf,count,dtype,op,comm)
IN sbuf
OUT rbuf
IN count
IN dtype
IN op
IN comm
* Exclusive scan not offered in MPI-1
* Implementations are possible w/out an identity or negation of op
Straw poll: 3/0/0
Inplace version to be accomplished by sbuf=MPI_INPLACE
internal buffering by implementations for this case is anticipated
non-blocking is MPI_IEXSCAN()
persistent is MPI_EXSCAN_INIT()
We discussed (at length) the "S" form of alltoall offered by Lloyd Lewins
The capability should be fleshed out for all collective operations. We
bureaucratically decided to use the "W" suffix instead of "S"