Dear all,
to explain the behavior of MPI_Reduce on our cluster i ran through the
source of Open MPI 1.2.6. On line 357 i found a mistake (maybe ;-)). It
should be:
return ompi_coll_tuned_reduce_intra_binary(sendbuf, recvbuf, count,
datatype, op, root, comm, segsize);
instead of
return ompi_coll_tuned_reduce_intra_pipeline (sendbuf, recvbuf, count,
datatype, op, root, comm, segsize);
There are 2 indications:
- the next branch is doing the same (32K pipelining)
- the comment /* Binary_32K */ sounds not like "pipeline" ;-)
Maybe someone is interested in.
Regards,
Andy
--
Dresden University of Technology
Center for Information Services
and High Performance Computing (ZIH)
D-01062 Dresden
Germany
Phone: (+49) 351/463-38783
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e-mail: Andy.Georgi_at_[hidden]
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