After reading the latest copy of the external chapter
I have the following question:
Will the values of MPI_COMM_ID_UNIQUE, MPI_COMM_ID_GLOBAL
and MPI_COMM_ID_NOT_GLOBAL (as mentioned in section 6.3.4
page 15 lines 9-28) become redundant due to the new
dynamic abilities of MPI-2? For example when two sets
of independant processes join together there will be
two MPI_COMM_WORLDs, also the superset of all processes
will not be readily identifiable. Having global or
unique identifiers in one process is alright but trying
to ensure that they are global or unique across all
jobs that might merge is another. With these new
dynamic abilities it will be harder for a profiler or
debugger to uniquely identify a process as rank in
MPI_COMM_WORLD does not have the same meaning as in
MPI-1 and no superset or universe of worlds is
readily identifiable without tracing many calls.
Regards,
Mark.
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Mark Fallon Email: mark.fallon@hdl.ie
Hitachi Dublin Laboratory mlfallon@crl.hitachi.co.jp
O'Reilly Institute
Trinity College Tel: +353-1-6798911
Dublin Fax: +353-1-6798926
Ireland
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