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openmpi/ompi/mca/coll/sm/coll_sm_allreduce.c
2015-06-23 20:59:57 -07:00

61 строка
2.2 KiB
C

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2005 The University of Tennessee and The University
* of Tennessee Research Foundation. All rights
* reserved.
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
* University of Stuttgart. All rights reserved.
* Copyright (c) 2004-2005 The Regents of the University of California.
* All rights reserved.
* Copyright (c) 2009 Cisco Systems, Inc. All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
/** @file */
#include "ompi_config.h"
#include "ompi/constants.h"
#include "ompi/communicator/communicator.h"
#include "coll_sm.h"
/**
* Shared memory allreduce.
*
* For the moment, all we're doing is a reduce to root==0 and then a
* broadcast. It is possible that we'll do something better someday.
*/
int mca_coll_sm_allreduce_intra(void *sbuf, void *rbuf, int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
int ret;
/* Note that only the root can pass MPI_IN_PLACE to MPI_REDUCE, so
have slightly different logic for that case. */
if (MPI_IN_PLACE == sbuf) {
int rank = ompi_comm_rank(comm);
if (0 == rank) {
ret = mca_coll_sm_reduce_intra(sbuf, rbuf, count, dtype, op, 0,
comm, module);
} else {
ret = mca_coll_sm_reduce_intra(rbuf, NULL, count, dtype, op, 0,
comm, module);
}
} else {
ret = mca_coll_sm_reduce_intra(sbuf, rbuf, count, dtype, op, 0,
comm, module);
}
return (ret == OMPI_SUCCESS) ?
mca_coll_sm_bcast_intra(rbuf, count, dtype, 0, comm, module) : ret;
}