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openmpi/ompi/mca/coll/inter/coll_inter_gather.c
George Bosilca 366d64b7e5 Move the collective structure outside the communicator.
As we changed the ABI (forcing a major release), we can limit
the size of the predefined communicators by moving the collective
structure outside the communicator. This might have a minimal,
but unnoticeable, impact on performance. This approach has been
discussed during the January 2017 devel meeting.

Signed-off-by: George Bosilca <bosilca@icl.utk.edu>
Signed-off-by: Joshua Hursey <jhursey@us.ibm.com>
2017-02-27 11:54:17 -06:00

100 строки
3.2 KiB
C

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2017 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) 2015-2016 Research Organization for Information Science
* and Technology (RIST). All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "coll_inter.h"
#include "mpi.h"
#include "ompi/constants.h"
#include "ompi/datatype/ompi_datatype.h"
#include "ompi/mca/coll/coll.h"
#include "ompi/mca/coll/base/coll_tags.h"
#include "ompi/mca/pml/pml.h"
/*
* gather_inter
*
* Function: - basic gather operation
* Accepts: - same arguments as MPI_Gather()
* Returns: - MPI_SUCCESS or error code
*/
int
mca_coll_inter_gather_inter(const void *sbuf, int scount,
struct ompi_datatype_t *sdtype,
void *rbuf, int rcount,
struct ompi_datatype_t *rdtype,
int root, struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
int err;
int rank;
int size;
size = ompi_comm_remote_size(comm);
rank = ompi_comm_rank(comm);
if (MPI_PROC_NULL == root) {
/* do nothing */
err = OMPI_SUCCESS;
} else if (MPI_ROOT != root) {
/* Perform the gather locally with the first process as root */
char *ptmp_free = NULL, *ptmp;
int size_local;
ptrdiff_t gap, span;
size_local = ompi_comm_size(comm->c_local_comm);
span = opal_datatype_span(&sdtype->super, (int64_t)scount*(int64_t)size_local, &gap);
ptmp_free = (char*)malloc(span);
if (NULL == ptmp_free) {
return OMPI_ERR_OUT_OF_RESOURCE;
}
ptmp = ptmp_free - gap;
err = comm->c_local_comm->c_coll->coll_gather(sbuf, scount, sdtype,
ptmp, scount, sdtype,
0, comm->c_local_comm,
comm->c_local_comm->c_coll->coll_gather_module);
if (0 == rank) {
/* First process sends data to the root */
err = MCA_PML_CALL(send(ptmp, scount*size_local, sdtype, root,
MCA_COLL_BASE_TAG_GATHER,
MCA_PML_BASE_SEND_STANDARD, comm));
if (OMPI_SUCCESS != err) {
return err;
}
}
free(ptmp_free);
} else {
/* I am the root, loop receiving the data. */
err = MCA_PML_CALL(recv(rbuf, rcount*size, rdtype, 0,
MCA_COLL_BASE_TAG_GATHER,
comm, MPI_STATUS_IGNORE));
if (OMPI_SUCCESS != err) {
return err;
}
}
/* All done */
return err;
}