a non blocking collective might return ompi_request_null, so we should not
retain anything in that case.
Signed-off-by: Gilles Gouaillardet <gilles@rist.or.jp>
Since ompi_coll_base_nbc_request_t is to be used in an
opal_free_list_t, it must be returned into a "clean" state.
So cleanup some data in the callback completion subroutines.
This fixes a regression introduced in open-mpi/ompi@0fe756d416
Signed-off-by: Gilles Gouaillardet <gilles@rist.or.jp>
MPI standard states a user MPI_Op and/or user MPI_Datatype can be free'd
after a call to a non blocking collective and before the non-blocking
collective completes.
Retain user (only) MPI_Op and MPI_Datatype when the non blocking call is
invoked, and set a request callback so they are free'd when the MPI_Request
completes.
Thanks Thomas Ponweiser for reporting this
Fixesopen-mpi/ompi#2151Fixesopen-mpi/ompi#1304
Signed-off-by: Gilles Gouaillardet <gilles@rist.or.jp>
Implements butterfly algorithm for MPI_Reduce_scatter.
The algorithm can be used both by commutative and non-commutative operations, for power-of-two and non-power-of-two number of processes.
Signed-off-by: Mikhail Kurnosov <mkurnosov@gmail.com>
Based on current implementation it is faster to use a blocking
send than the non-blocking version. Switch the exchange function
used in the barrier to use the blocking version combined with
the non-blocking version of the receive.
This is similar to open-mpi/ompi@223d75595d
