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

97 строки
3.0 KiB
C

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2014 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) 2006-2007 University of Houston. All rights reserved.
* Copyright (c) 2013 Cisco Systems, Inc. All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "coll_inter.h"
#include <stdio.h>
#include "mpi.h"
#include "ompi/constants.h"
#include "ompi/mca/coll/coll.h"
#include "ompi/mca/coll/base/coll_tags.h"
#include "ompi/op/op.h"
#include "ompi/mca/pml/pml.h"
/*
* reduce_inter
*
* Function: - reduction using the local_comm
* Accepts: - same as MPI_Reduce()
* Returns: - MPI_SUCCESS or error code
*/
int
mca_coll_inter_reduce_inter(void *sbuf, void *rbuf, int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
int root, struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
int rank, err;
ptrdiff_t true_lb, true_extent, lb, extent;
char *free_buffer = NULL;
char *pml_buffer = NULL;
/* Initialize */
rank = ompi_comm_rank(comm);
if (MPI_PROC_NULL == root) {
/* do nothing */
err = OMPI_SUCCESS;
} else if (MPI_ROOT != root) {
/* Perform the reduce locally with the first process as root */
ompi_datatype_get_extent(dtype, &lb, &extent);
ompi_datatype_get_true_extent(dtype, &true_lb, &true_extent);
free_buffer = (char*)malloc(true_extent + (count - 1) * extent);
if (NULL == free_buffer) {
return OMPI_ERR_OUT_OF_RESOURCE;
}
pml_buffer = free_buffer - true_lb;
err = comm->c_local_comm->c_coll.coll_reduce(sbuf, pml_buffer, count,
dtype, op, 0, comm->c_local_comm,
comm->c_local_comm->c_coll.coll_reduce_module);
if (0 == rank) {
/* First process sends the result to the root */
err = MCA_PML_CALL(send(pml_buffer, count, dtype, root,
MCA_COLL_BASE_TAG_REDUCE,
MCA_PML_BASE_SEND_STANDARD, comm));
if (OMPI_SUCCESS != err) {
return err;
}
}
if (NULL != free_buffer) {
free(free_buffer);
}
} else {
/* Root receives the reduced message from the first process */
err = MCA_PML_CALL(recv(rbuf, count, dtype, 0,
MCA_COLL_BASE_TAG_REDUCE, comm,
MPI_STATUS_IGNORE));
if (OMPI_SUCCESS != err) {
return err;
}
}
/* All done */
return err;
}