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/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2006 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.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "coll_basic.h"
#include <stdio.h>
#include <errno.h>
#include "mpi.h"
#include "ompi/constants.h"
#include "ompi/mca/coll/coll.h"
#include "ompi/mca/coll/base/coll_tags.h"
#include "coll_basic.h"
#include "ompi/op/op.h"
/*
* reduce_scatter
*
* Function: - reduce then scatter
* Accepts: - same as MPI_Reduce_scatter()
* Returns: - MPI_SUCCESS or error code
*/
int
mca_coll_basic_reduce_scatter_intra(void *sbuf, void *rbuf, int *rcounts,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm)
{
int i, err, rank, size, count;
ptrdiff_t true_lb, true_extent, lb, extent;
int *disps = NULL;
char *free_buffer = NULL;
char *pml_buffer = NULL;
/* Initialize */
rank = ompi_comm_rank(comm);
size = ompi_comm_size(comm);
/* Initialize reduce & scatterv info at the root (rank 0). */
for (i = 0, count = 0; i < size; ++i) {
if (rcounts[i] < 0) {
return MPI_ERR_ARG;
}
count += rcounts[i];
}
if (0 == rank) {
disps = (int*)malloc((unsigned) size * sizeof(int));
if (NULL == disps) {
return OMPI_ERR_OUT_OF_RESOURCE;
}
/* There is lengthy rationale about how this malloc works in
* coll_basic_reduce.c */
ompi_ddt_get_extent(dtype, &lb, &extent);
ompi_ddt_get_true_extent(dtype, &true_lb, &true_extent);
free_buffer = (char*)malloc(true_extent + (count - 1) * extent);
if (NULL == free_buffer) {
free(disps);
return OMPI_ERR_OUT_OF_RESOURCE;
}
pml_buffer = free_buffer - lb;
disps[0] = 0;
for (i = 0; i < (size - 1); ++i) {
disps[i + 1] = disps[i] + rcounts[i];
}
}
/* Handle MPI_IN_PLACE */
if (MPI_IN_PLACE == sbuf) {
sbuf = rbuf;
}
/* reduction */
err =
comm->c_coll.coll_reduce(sbuf, pml_buffer, count, dtype, op, 0,
comm);
/* scatter */
if (MPI_SUCCESS == err) {
err = comm->c_coll.coll_scatterv(pml_buffer, rcounts, disps, dtype,
rbuf, rcounts[rank], dtype, 0,
comm);
}
/* All done */
if (NULL != disps) {
free(disps);
}
if (NULL != free_buffer) {
free(free_buffer);
}
return err;
}
/*
* reduce_scatter_inter
*
* Function: - reduce/scatter operation
* Accepts: - same arguments as MPI_Reduce_scatter()
* Returns: - MPI_SUCCESS or error code
*/
int
mca_coll_basic_reduce_scatter_inter(void *sbuf, void *rbuf, int *rcounts,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm)
{
int err, i, rank, root = 0, rsize;
int totalcounts, tcount;
ptrdiff_t lb, extent;
char *tmpbuf = NULL, *tmpbuf2 = NULL, *tbuf = NULL;
ompi_request_t *req;
ompi_request_t **reqs = comm->c_coll_basic_data->mccb_reqs;
rank = ompi_comm_rank(comm);
rsize = ompi_comm_remote_size(comm);
/* According to MPI-2, the total sum of elements transfered has to
* be identical in both groups. Thus, it is enough to calculate
* that locally.
*/
for (totalcounts = 0, i = 0; i < rsize; i++) {
totalcounts += rcounts[i];
}
/* determine result of the remote group, you cannot
* use coll_reduce for inter-communicators, since than
* you would need to determine an order between the
* two groups (e.g. which group is providing the data
* and which one enters coll_reduce with providing
* MPI_PROC_NULL as root argument etc.) Here,
* we execute the data exchange for both groups
* simultaniously. */
/*****************************************************************/
if (rank == root) {
err = ompi_ddt_get_extent(dtype, &lb, &extent);
if (OMPI_SUCCESS != err) {
return OMPI_ERROR;
}
tmpbuf = (char *) malloc(totalcounts * extent);
tmpbuf2 = (char *) malloc(totalcounts * extent);
if (NULL == tmpbuf || NULL == tmpbuf2) {
return OMPI_ERR_OUT_OF_RESOURCE;
}
/* Do a send-recv between the two root procs. to avoid deadlock */
err = MCA_PML_CALL(isend(sbuf, totalcounts, dtype, 0,
MCA_COLL_BASE_TAG_REDUCE_SCATTER,
MCA_PML_BASE_SEND_STANDARD, comm, &req));
if (OMPI_SUCCESS != err) {
goto exit;
}
err = MCA_PML_CALL(recv(tmpbuf2, totalcounts, dtype, 0,
MCA_COLL_BASE_TAG_REDUCE_SCATTER, comm,
MPI_STATUS_IGNORE));
if (OMPI_SUCCESS != err) {
goto exit;
}
err = ompi_request_wait_all(1, &req, MPI_STATUS_IGNORE);
if (OMPI_SUCCESS != err) {
goto exit;
}
/* Loop receiving and calling reduction function (C or Fortran)
* The result of this reduction operations is then in
* tmpbuf2.
*/
for (i = 1; i < rsize; i++) {
err = MCA_PML_CALL(recv(tmpbuf, totalcounts, dtype, i,
MCA_COLL_BASE_TAG_REDUCE_SCATTER, comm,
MPI_STATUS_IGNORE));
if (MPI_SUCCESS != err) {
goto exit;
}
/* Perform the reduction */
ompi_op_reduce(op, tmpbuf, tmpbuf2, totalcounts, dtype);
}
} else {
/* If not root, send data to the root. */
err = MCA_PML_CALL(send(sbuf, totalcounts, dtype, root,
MCA_COLL_BASE_TAG_REDUCE_SCATTER,
MCA_PML_BASE_SEND_STANDARD, comm));
if (OMPI_SUCCESS != err) {
goto exit;
}
}
/* now we have on one process the result of the remote group. To distribute
* the data to all processes in the local group, we exchange the data between
* the two root processes. They then send it to every other process in the
* remote group.
*/
/***************************************************************************/
if (rank == root) {
/* sendrecv between the two roots */
err = MCA_PML_CALL(irecv(tmpbuf, totalcounts, dtype, 0,
MCA_COLL_BASE_TAG_REDUCE_SCATTER,
comm, &req));
if (OMPI_SUCCESS != err) {
goto exit;
}
err = MCA_PML_CALL(send(tmpbuf2, totalcounts, dtype, 0,
MCA_COLL_BASE_TAG_REDUCE_SCATTER,
MCA_PML_BASE_SEND_STANDARD, comm));
if (OMPI_SUCCESS != err) {
goto exit;
}
err = ompi_request_wait_all(1, &req, MPI_STATUS_IGNORE);
if (OMPI_SUCCESS != err) {
goto exit;
}
/* distribute the data to other processes in remote group.
* Note that we start from 1 (not from zero), since zero
* has already the correct data AND we avoid a potential
* deadlock here.
*/
err = MCA_PML_CALL(irecv(rbuf, rcounts[rank], dtype, root,
MCA_COLL_BASE_TAG_REDUCE_SCATTER,
comm, &req));
tcount = 0;
for (i = 0; i < rsize; i++) {
tbuf = (char *) tmpbuf + tcount * extent;
err = MCA_PML_CALL(isend(tbuf, rcounts[i], dtype, i,
MCA_COLL_BASE_TAG_REDUCE_SCATTER,
MCA_PML_BASE_SEND_STANDARD, comm,
reqs++));
if (OMPI_SUCCESS != err) {
goto exit;
}
tcount += rcounts[i];
}
err =
ompi_request_wait_all(rsize,
comm->c_coll_basic_data->mccb_reqs,
MPI_STATUSES_IGNORE);
if (OMPI_SUCCESS != err) {
goto exit;
}
err = ompi_request_wait_all(1, &req, MPI_STATUS_IGNORE);
if (OMPI_SUCCESS != err) {
goto exit;
}
} else {
err = MCA_PML_CALL(recv(rbuf, rcounts[rank], dtype, root,
MCA_COLL_BASE_TAG_REDUCE_SCATTER,
comm, MPI_STATUS_IGNORE));
}
exit:
if (NULL != tmpbuf) {
free(tmpbuf);
}
if (NULL != tmpbuf2) {
free(tmpbuf2);
}
return err;
}
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