1210 строки
46 KiB
C
1210 строки
46 KiB
C
/* -*- Mode: C; c-basic-offset:2 ; indent-tabs-mode:nil -*- */
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/*
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* Copyright (c) 2006 The Trustees of Indiana University and Indiana
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* University Research and Technology
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* Corporation. All rights reserved.
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* Copyright (c) 2006 The Technical University of Chemnitz. All
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* rights reserved.
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* Copyright (c) 2013-2017 Los Alamos National Security, LLC. All rights
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* reserved.
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* Copyright (c) 2014-2018 Research Organization for Information Science
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* and Technology (RIST). All rights reserved.
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* Copyright (c) 2017 IBM Corporation. All rights reserved.
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* Copyright (c) 2018 FUJITSU LIMITED. All rights reserved.
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* $COPYRIGHT$
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*
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* Additional copyrights may follow
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*
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* Author(s): Torsten Hoefler <htor@cs.indiana.edu>
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*
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*/
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#include "nbc_internal.h"
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#include "ompi/communicator/communicator.h"
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#include "ompi/datatype/ompi_datatype.h"
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#include "ompi/op/op.h"
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#include "opal/util/bit_ops.h"
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#include <assert.h>
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static inline int allred_sched_diss(int rank, int p, int count, MPI_Datatype datatype, ptrdiff_t gap, const void *sendbuf,
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void *recvbuf, MPI_Op op, char inplace, NBC_Schedule *schedule, void *tmpbuf);
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static inline int allred_sched_recursivedoubling(int rank, int p, const void *sendbuf, void *recvbuf,
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int count, MPI_Datatype datatype, ptrdiff_t gap, MPI_Op op,
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char inplace, NBC_Schedule *schedule, void *tmpbuf);
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static inline int allred_sched_ring(int rank, int p, int count, MPI_Datatype datatype, const void *sendbuf,
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void *recvbuf, MPI_Op op, int size, int ext, NBC_Schedule *schedule,
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void *tmpbuf);
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static inline int allred_sched_linear(int rank, int p, const void *sendbuf, void *recvbuf, int count,
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MPI_Datatype datatype, ptrdiff_t gap, MPI_Op op, int ext, int size,
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NBC_Schedule *schedule, void *tmpbuf);
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static inline int allred_sched_redscat_allgather(
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int rank, int comm_size, int count, MPI_Datatype datatype, ptrdiff_t gap,
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const void *sbuf, void *rbuf, MPI_Op op, char inplace,
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NBC_Schedule *schedule, void *tmpbuf, struct ompi_communicator_t *comm);
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#ifdef NBC_CACHE_SCHEDULE
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/* tree comparison function for schedule cache */
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int NBC_Allreduce_args_compare(NBC_Allreduce_args *a, NBC_Allreduce_args *b, void *param) {
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if ((a->sendbuf == b->sendbuf) &&
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(a->recvbuf == b->recvbuf) &&
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(a->count == b->count) &&
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(a->datatype == b->datatype) &&
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(a->op == b->op)) {
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return 0;
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}
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if( a->sendbuf < b->sendbuf ) {
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return -1;
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}
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return 1;
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}
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#endif
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static int nbc_allreduce_init(const void* sendbuf, void* recvbuf, int count, MPI_Datatype datatype, MPI_Op op,
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struct ompi_communicator_t *comm, ompi_request_t ** request,
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struct mca_coll_base_module_2_3_0_t *module, bool persistent)
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{
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int rank, p, res;
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ptrdiff_t ext, lb;
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NBC_Schedule *schedule;
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size_t size;
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#ifdef NBC_CACHE_SCHEDULE
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NBC_Allreduce_args *args, *found, search;
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#endif
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enum { NBC_ARED_BINOMIAL, NBC_ARED_RING, NBC_ARED_REDSCAT_ALLGATHER, NBC_ARED_RDBL } alg;
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char inplace;
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void *tmpbuf = NULL;
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ompi_coll_libnbc_module_t *libnbc_module = (ompi_coll_libnbc_module_t*) module;
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ptrdiff_t span, gap;
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NBC_IN_PLACE(sendbuf, recvbuf, inplace);
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rank = ompi_comm_rank (comm);
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p = ompi_comm_size (comm);
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res = ompi_datatype_get_extent(datatype, &lb, &ext);
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if (OMPI_SUCCESS != res) {
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NBC_Error ("MPI Error in ompi_datatype_type_extent() (%i)", res);
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return res;
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}
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res = ompi_datatype_type_size (datatype, &size);
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if (OMPI_SUCCESS != res) {
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NBC_Error ("MPI Error in ompi_datatype_type_size() (%i)", res);
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return res;
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}
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if (1 == p && (!persistent || inplace)) {
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if (!inplace) {
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/* for a single node - copy data to receivebuf */
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res = NBC_Copy(sendbuf, count, datatype, recvbuf, count, datatype, comm);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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return res;
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}
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}
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return nbc_get_noop_request(persistent, request);
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}
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span = opal_datatype_span(&datatype->super, count, &gap);
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tmpbuf = malloc (span);
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if (OPAL_UNLIKELY(NULL == tmpbuf)) {
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return OMPI_ERR_OUT_OF_RESOURCE;
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}
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/* algorithm selection */
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int nprocs_pof2 = opal_next_poweroftwo(p) >> 1;
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if (libnbc_iallreduce_algorithm == 0) {
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if(p < 4 || size*count < 65536 || !ompi_op_is_commute(op) || inplace) {
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alg = NBC_ARED_BINOMIAL;
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} else if (count >= nprocs_pof2 && ompi_op_is_commute(op)) {
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alg = NBC_ARED_REDSCAT_ALLGATHER;
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} else {
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alg = NBC_ARED_RING;
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}
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} else {
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if (libnbc_iallreduce_algorithm == 1)
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alg = NBC_ARED_RING;
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else if (libnbc_iallreduce_algorithm == 2)
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alg = NBC_ARED_BINOMIAL;
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else if (libnbc_iallreduce_algorithm == 3 && count >= nprocs_pof2 && ompi_op_is_commute(op))
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alg = NBC_ARED_REDSCAT_ALLGATHER;
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else if (libnbc_iallreduce_algorithm == 4)
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alg = NBC_ARED_RDBL;
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else
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alg = NBC_ARED_RING;
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}
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#ifdef NBC_CACHE_SCHEDULE
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/* search schedule in communicator specific tree */
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search.sendbuf = sendbuf;
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search.recvbuf = recvbuf;
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search.count = count;
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search.datatype = datatype;
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search.op = op;
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found = (NBC_Allreduce_args *) hb_tree_search ((hb_tree *) libnbc_module->NBC_Dict[NBC_ALLREDUCE], &search);
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if (NULL == found) {
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#endif
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schedule = OBJ_NEW(NBC_Schedule);
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if (NULL == schedule) {
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free(tmpbuf);
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return OMPI_ERR_OUT_OF_RESOURCE;
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}
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if (p == 1) {
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res = NBC_Sched_copy((void *)sendbuf, false, count, datatype,
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recvbuf, false, count, datatype, schedule, false);
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} else {
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switch(alg) {
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case NBC_ARED_BINOMIAL:
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res = allred_sched_diss(rank, p, count, datatype, gap, sendbuf, recvbuf, op, inplace, schedule, tmpbuf);
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break;
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case NBC_ARED_REDSCAT_ALLGATHER:
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res = allred_sched_redscat_allgather(rank, p, count, datatype, gap, sendbuf, recvbuf, op, inplace, schedule, tmpbuf, comm);
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break;
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case NBC_ARED_RING:
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res = allred_sched_ring(rank, p, count, datatype, sendbuf, recvbuf, op, size, ext, schedule, tmpbuf);
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break;
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case NBC_ARED_RDBL:
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res = allred_sched_recursivedoubling(rank, p, sendbuf, recvbuf, count, datatype, gap, op, inplace, schedule, tmpbuf);
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break;
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}
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}
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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OBJ_RELEASE(schedule);
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free(tmpbuf);
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return res;
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}
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res = NBC_Sched_commit(schedule);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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OBJ_RELEASE(schedule);
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free(tmpbuf);
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return res;
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}
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#ifdef NBC_CACHE_SCHEDULE
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/* save schedule to tree */
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args = (NBC_Allreduce_args *) malloc (sizeof(args));
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if (NULL != args) {
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args->sendbuf = sendbuf;
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args->recvbuf = recvbuf;
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args->count = count;
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args->datatype = datatype;
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args->op = op;
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args->schedule = schedule;
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res = hb_tree_insert ((hb_tree *) libnbc_module->NBC_Dict[NBC_ALLREDUCE], args, args, 0);
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if (0 == res) {
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OBJ_RETAIN(schedule);
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/* increase number of elements for A2A */
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if (++libnbc_module->NBC_Dict_size[NBC_ALLREDUCE] > NBC_SCHED_DICT_UPPER) {
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NBC_SchedCache_dictwipe ((hb_tree *) libnbc_module->NBC_Dict[NBC_ALLREDUCE],
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&libnbc_module->NBC_Dict_size[NBC_ALLREDUCE]);
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}
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} else {
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NBC_Error("error in dict_insert() (%i)", res);
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free (args);
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}
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}
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} else {
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/* found schedule */
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schedule = found->schedule;
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OBJ_RETAIN(schedule);
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}
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#endif
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res = NBC_Schedule_request (schedule, comm, libnbc_module, persistent, request, tmpbuf);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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OBJ_RELEASE(schedule);
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free(tmpbuf);
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return res;
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}
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return OMPI_SUCCESS;
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}
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int ompi_coll_libnbc_iallreduce(const void* sendbuf, void* recvbuf, int count, MPI_Datatype datatype, MPI_Op op,
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struct ompi_communicator_t *comm, ompi_request_t ** request,
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struct mca_coll_base_module_2_3_0_t *module) {
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int res = nbc_allreduce_init(sendbuf, recvbuf, count, datatype, op,
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comm, request, module, false);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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return res;
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}
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res = NBC_Start(*(ompi_coll_libnbc_request_t **)request);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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NBC_Return_handle (*(ompi_coll_libnbc_request_t **)request);
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*request = &ompi_request_null.request;
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return res;
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}
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return OMPI_SUCCESS;
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}
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static int nbc_allreduce_inter_init(const void* sendbuf, void* recvbuf, int count, MPI_Datatype datatype, MPI_Op op,
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struct ompi_communicator_t *comm, ompi_request_t ** request,
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struct mca_coll_base_module_2_3_0_t *module, bool persistent)
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{
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int rank, res, rsize;
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size_t size;
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MPI_Aint ext;
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NBC_Schedule *schedule;
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void *tmpbuf = NULL;
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ompi_coll_libnbc_module_t *libnbc_module = (ompi_coll_libnbc_module_t*) module;
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ptrdiff_t span, gap;
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rank = ompi_comm_rank (comm);
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rsize = ompi_comm_remote_size (comm);
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res = ompi_datatype_type_extent(datatype, &ext);
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if (MPI_SUCCESS != res) {
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NBC_Error("MPI Error in ompi_datatype_type_extent() (%i)", res);
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return res;
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}
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res = ompi_datatype_type_size(datatype, &size);
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if (MPI_SUCCESS != res) {
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NBC_Error("MPI Error in ompi_datatype_type_size() (%i)", res);
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return res;
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}
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span = opal_datatype_span(&datatype->super, count, &gap);
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tmpbuf = malloc (span);
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if (OPAL_UNLIKELY(NULL == tmpbuf)) {
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return OMPI_ERR_OUT_OF_RESOURCE;
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}
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schedule = OBJ_NEW(NBC_Schedule);
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if (OPAL_UNLIKELY(NULL == schedule)) {
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free(tmpbuf);
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return OMPI_ERR_OUT_OF_RESOURCE;
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}
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res = allred_sched_linear (rank, rsize, sendbuf, recvbuf, count, datatype, gap, op,
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ext, size, schedule, tmpbuf);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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OBJ_RELEASE(schedule);
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free(tmpbuf);
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return res;
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}
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res = NBC_Sched_commit(schedule);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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OBJ_RELEASE(schedule);
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free(tmpbuf);
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return res;
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}
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res = NBC_Schedule_request(schedule, comm, libnbc_module, persistent, request, tmpbuf);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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OBJ_RELEASE(schedule);
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free(tmpbuf);
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return res;
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}
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return OMPI_SUCCESS;
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}
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int ompi_coll_libnbc_iallreduce_inter(const void* sendbuf, void* recvbuf, int count, MPI_Datatype datatype, MPI_Op op,
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struct ompi_communicator_t *comm, ompi_request_t ** request,
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struct mca_coll_base_module_2_3_0_t *module) {
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int res = nbc_allreduce_inter_init(sendbuf, recvbuf, count, datatype, op,
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comm, request, module, false);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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return res;
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}
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res = NBC_Start(*(ompi_coll_libnbc_request_t **)request);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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NBC_Return_handle (*(ompi_coll_libnbc_request_t **)request);
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*request = &ompi_request_null.request;
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return res;
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}
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return OMPI_SUCCESS;
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}
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/* binomial allreduce (binomial tree up and binomial bcast down)
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* working principle:
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* - each node gets a virtual rank vrank
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* - the 'root' node get vrank 0
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* - node 0 gets the vrank of the 'root'
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* - all other ranks stay identical (they do not matter)
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*
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* Algorithm:
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* pairwise exchange
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* round r:
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* grp = rank % 2^r
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* if grp == 0: receive from rank + 2^(r-1) if it exists and reduce value
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* if grp == 1: send to rank - 2^(r-1) and exit function
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*
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* do this for R=log_2(p) rounds
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* followed by a Bcast:
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* Algorithm:
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* - each node with vrank > 2^r and vrank < 2^r+1 receives from node
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* vrank - 2^r (vrank=1 receives from 0, vrank 0 receives never)
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* - each node sends each round r to node vrank + 2^r
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* - a node stops to send if 2^r > commsize
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*
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*/
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#define RANK2VRANK(rank, vrank, root) \
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{ \
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vrank = rank; \
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if (rank == 0) vrank = root; \
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if (rank == root) vrank = 0; \
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}
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#define VRANK2RANK(rank, vrank, root) \
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{ \
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rank = vrank; \
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if (vrank == 0) rank = root; \
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if (vrank == root) rank = 0; \
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}
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static inline int allred_sched_diss(int rank, int p, int count, MPI_Datatype datatype, ptrdiff_t gap, const void *sendbuf, void *recvbuf,
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MPI_Op op, char inplace, NBC_Schedule *schedule, void *tmpbuf) {
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int root, vrank, maxr, vpeer, peer, res;
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char *rbuf, *lbuf, *buf;
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int tmprbuf, tmplbuf;
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root = 0; /* this makes the code for ireduce and iallreduce nearly identical - could be changed to improve performance */
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RANK2VRANK(rank, vrank, root);
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maxr = (int)ceil((log((double)p)/LOG2));
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/* ensure the result ends up in recvbuf on vrank 0 */
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if (0 == (maxr%2)) {
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rbuf = (void *)(-gap);
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tmprbuf = true;
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lbuf = recvbuf;
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tmplbuf = false;
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} else {
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lbuf = (void *)(-gap);
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tmplbuf = true;
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rbuf = recvbuf;
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tmprbuf = false;
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if (inplace) {
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res = NBC_Sched_copy(rbuf, false, count, datatype,
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((char *)tmpbuf) - gap, false, count, datatype,
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schedule, true);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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return res;
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}
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}
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}
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for (int r = 1, firstred = 1 ; r <= maxr ; ++r) {
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if ((vrank % (1 << r)) == 0) {
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/* we have to receive this round */
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vpeer = vrank + (1 << (r - 1));
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VRANK2RANK(peer, vpeer, root)
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if (peer < p) {
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/* we have to wait until we have the data */
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res = NBC_Sched_recv (rbuf, tmprbuf, count, datatype, peer, schedule, true);
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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return res;
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}
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/* this cannot be done until tmpbuf is unused :-( so barrier after the op */
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if (firstred && !inplace) {
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/* perform the reduce with the senbuf */
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res = NBC_Sched_op (sendbuf, false, rbuf, tmprbuf, count, datatype, op, schedule, true);
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firstred = 0;
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} else {
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/* perform the reduce in my local buffer */
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res = NBC_Sched_op (lbuf, tmplbuf, rbuf, tmprbuf, count, datatype, op, schedule, true);
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}
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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return res;
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}
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/* swap left and right buffers */
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buf = rbuf; rbuf = lbuf ; lbuf = buf;
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tmprbuf ^= 1; tmplbuf ^= 1;
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}
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} else {
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/* we have to send this round */
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vpeer = vrank - (1 << (r - 1));
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VRANK2RANK(peer, vpeer, root)
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if (firstred && !inplace) {
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/* we have to use the sendbuf in the first round .. */
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res = NBC_Sched_send (sendbuf, false, count, datatype, peer, schedule, false);
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} else {
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/* and the recvbuf in all remaining rounds */
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res = NBC_Sched_send (lbuf, tmplbuf, count, datatype, peer, schedule, false);
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}
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if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
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return res;
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}
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/* leave the game */
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break;
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}
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}
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/* this is the Bcast part - copied with minor changes from nbc_ibcast.c
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* changed: buffer -> recvbuf */
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RANK2VRANK(rank, vrank, root);
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/* receive from the right hosts */
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if (vrank != 0) {
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for (int r = 0; r < maxr ; ++r) {
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if ((vrank >= (1 << r)) && (vrank < (1 << (r + 1)))) {
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VRANK2RANK(peer, vrank - (1 << r), root);
|
|
res = NBC_Sched_recv (recvbuf, false, count, datatype, peer, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
}
|
|
}
|
|
|
|
res = NBC_Sched_barrier (schedule);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
}
|
|
|
|
if (0 == vrank) assert(lbuf == recvbuf);
|
|
/* now send to the right hosts */
|
|
for (int r = 0; r < maxr; ++r) {
|
|
if (((vrank + (1 << r) < p) && (vrank < (1 << r))) || (vrank == 0)) {
|
|
VRANK2RANK(peer, vrank + (1 << r), root);
|
|
res = NBC_Sched_send (recvbuf, false, count, datatype, peer, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* end of the bcast */
|
|
return OMPI_SUCCESS;
|
|
}
|
|
|
|
/*
|
|
* allred_sched_recursivedoubling
|
|
*
|
|
* Function: Recursive doubling algorithm for iallreduce operation
|
|
*
|
|
* Description: Implements recursive doubling algorithm for iallreduce.
|
|
* The algorithm preserves order of operations so it can
|
|
* be used both by commutative and non-commutative operations.
|
|
* Schedule length: O(\log(p))
|
|
* Memory requirements:
|
|
* Each process requires a temporary buffer: count * typesize = O(count)
|
|
*
|
|
* Example on 7 nodes:
|
|
* Initial state
|
|
* # 0 1 2 3 4 5 6
|
|
* [0] [1] [2] [3] [4] [5] [6]
|
|
* Initial adjustment step for non-power of two nodes.
|
|
* old rank 1 3 5 6
|
|
* new rank 0 1 2 3
|
|
* [0+1] [2+3] [4+5] [6]
|
|
* Step 1
|
|
* old rank 1 3 5 6
|
|
* new rank 0 1 2 3
|
|
* [0+1+] [0+1+] [4+5+] [4+5+]
|
|
* [2+3+] [2+3+] [6 ] [6 ]
|
|
* Step 2
|
|
* old rank 1 3 5 6
|
|
* new rank 0 1 2 3
|
|
* [0+1+] [0+1+] [0+1+] [0+1+]
|
|
* [2+3+] [2+3+] [2+3+] [2+3+]
|
|
* [4+5+] [4+5+] [4+5+] [4+5+]
|
|
* [6 ] [6 ] [6 ] [6 ]
|
|
* Final adjustment step for non-power of two nodes
|
|
* # 0 1 2 3 4 5 6
|
|
* [0+1+] [0+1+] [0+1+] [0+1+] [0+1+] [0+1+] [0+1+]
|
|
* [2+3+] [2+3+] [2+3+] [2+3+] [2+3+] [2+3+] [2+3+]
|
|
* [4+5+] [4+5+] [4+5+] [4+5+] [4+5+] [4+5+] [4+5+]
|
|
* [6 ] [6 ] [6 ] [6 ] [6 ] [6 ] [6 ]
|
|
*
|
|
*/
|
|
static inline int allred_sched_recursivedoubling(int rank, int p, const void *sendbuf, void *recvbuf,
|
|
int count, MPI_Datatype datatype, ptrdiff_t gap, MPI_Op op,
|
|
char inplace, NBC_Schedule *schedule, void *tmpbuf)
|
|
{
|
|
int res, pof2, nprocs_rem, vrank;
|
|
char *tmpsend = NULL, *tmprecv = NULL, *tmpswap = NULL;
|
|
|
|
tmpsend = (char*) tmpbuf - gap;
|
|
tmprecv = (char*) recvbuf;
|
|
|
|
if (inplace) {
|
|
res = NBC_Sched_copy(recvbuf, false, count, datatype,
|
|
tmpsend, false, count, datatype, schedule, true);
|
|
} else {
|
|
res = NBC_Sched_copy((void *)sendbuf, false, count, datatype,
|
|
tmpsend, false, count, datatype, schedule, true);
|
|
}
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { return res; }
|
|
|
|
/* Get nearest power of two less than or equal to comm size */
|
|
pof2 = opal_next_poweroftwo(p) >> 1;
|
|
|
|
/* Handle non-power-of-two case:
|
|
- Even ranks less than 2 * nprocs_rem send their data to (rank + 1), and
|
|
sets new rank to -1.
|
|
- Odd ranks less than 2 * nprocs_rem receive data from (rank - 1),
|
|
apply appropriate operation, and set new rank to rank/2
|
|
- Everyone else sets rank to rank - nprocs_rem
|
|
*/
|
|
nprocs_rem = p - pof2;
|
|
if (rank < 2 * nprocs_rem) {
|
|
if (0 == rank % 2) { /* Even */
|
|
res = NBC_Sched_send(tmpsend, false, count, datatype, rank + 1, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { return res; }
|
|
vrank = -1;
|
|
} else { /* Odd */
|
|
res = NBC_Sched_recv(tmprecv, false, count, datatype, rank - 1, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { return res; }
|
|
|
|
/* tmpsend = tmprecv (op) tmpsend */
|
|
res = NBC_Sched_op(tmprecv, false, tmpsend, false, count, datatype, op, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { return res; }
|
|
|
|
vrank = rank >> 1;
|
|
}
|
|
} else {
|
|
vrank = rank - nprocs_rem;
|
|
}
|
|
|
|
/* Communication/Computation loop
|
|
- Exchange message with remote node.
|
|
- Perform appropriate operation taking in account order of operations:
|
|
result = value (op) result
|
|
*/
|
|
if (0 <= vrank) {
|
|
for (int distance = 1; distance < pof2; distance <<= 1) {
|
|
int remote = vrank ^ distance;
|
|
|
|
/* Find real rank of remote node */
|
|
if (remote < nprocs_rem) {
|
|
remote = remote * 2 + 1;
|
|
} else {
|
|
remote += nprocs_rem;
|
|
}
|
|
|
|
/* Exchange the data */
|
|
res = NBC_Sched_send(tmpsend, false, count, datatype, remote, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { return res; }
|
|
|
|
res = NBC_Sched_recv(tmprecv, false, count, datatype, remote, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { return res; }
|
|
|
|
/* Apply operation */
|
|
if (rank < remote) {
|
|
/* tmprecv = tmpsend (op) tmprecv */
|
|
res = NBC_Sched_op(tmpsend, false, tmprecv, false,
|
|
count, datatype, op, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { return res; }
|
|
|
|
/* Swap tmpsend and tmprecv buffers */
|
|
tmpswap = tmprecv; tmprecv = tmpsend; tmpsend = tmpswap;
|
|
} else {
|
|
/* tmpsend = tmprecv (op) tmpsend */
|
|
res = NBC_Sched_op(tmprecv, false, tmpsend, false,
|
|
count, datatype, op, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { return res; }
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Handle non-power-of-two case:
|
|
- Even ranks less than 2 * nprocs_rem receive result from (rank + 1)
|
|
- Odd ranks less than 2 * nprocs_rem send result from tmpsend to (rank - 1)
|
|
*/
|
|
if (rank < 2 * nprocs_rem) {
|
|
if (0 == rank % 2) { /* Even */
|
|
res = NBC_Sched_recv(recvbuf, false, count, datatype, rank + 1, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { return res; }
|
|
tmpsend = (char *)recvbuf;
|
|
} else { /* Odd */
|
|
res = NBC_Sched_send(tmpsend, false, count, datatype, rank - 1, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { return res; }
|
|
}
|
|
}
|
|
|
|
/* Copy result back into recvbuf */
|
|
if (tmpsend != recvbuf) {
|
|
res = NBC_Sched_copy(tmpsend, false, count, datatype,
|
|
recvbuf, false, count, datatype, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { return res; }
|
|
}
|
|
|
|
return OMPI_SUCCESS;
|
|
}
|
|
|
|
static inline int allred_sched_ring (int r, int p, int count, MPI_Datatype datatype, const void *sendbuf, void *recvbuf, MPI_Op op,
|
|
int size, int ext, NBC_Schedule *schedule, void *tmpbuf) {
|
|
int segsize, *segsizes, *segoffsets; /* segment sizes and offsets per segment (number of segments == number of nodes */
|
|
int speer, rpeer; /* send and recvpeer */
|
|
int res = OMPI_SUCCESS;
|
|
|
|
if (count == 0) {
|
|
return OMPI_SUCCESS;
|
|
}
|
|
|
|
segsizes = (int *) malloc (sizeof (int) * p);
|
|
segoffsets = (int *) malloc (sizeof (int) * p);
|
|
if (NULL == segsizes || NULL == segoffsets) {
|
|
free (segsizes);
|
|
free (segoffsets);
|
|
return OMPI_ERR_OUT_OF_RESOURCE;
|
|
}
|
|
|
|
segsize = (count + p - 1) / p; /* size of the segments */
|
|
|
|
segoffsets[0] = 0;
|
|
for (int i = 0, mycount = count ; i < p ; ++i) {
|
|
mycount -= segsize;
|
|
segsizes[i] = segsize;
|
|
if (mycount < 0) {
|
|
segsizes[i] = segsize + mycount;
|
|
mycount = 0;
|
|
}
|
|
|
|
if (i) {
|
|
segoffsets[i] = segoffsets[i-1] + segsizes[i-1];
|
|
}
|
|
}
|
|
|
|
/* reduce peers */
|
|
speer = (r + 1) % p;
|
|
rpeer = (r - 1 + p) % p;
|
|
|
|
/* + -> reduced this round
|
|
* / -> sum (reduced in a previous step)
|
|
*
|
|
* *** round 0 ***
|
|
* 0 1 2
|
|
*
|
|
* 00 10 20 0: [1] -> 1
|
|
* 01 11 21 1: [2] -> 2
|
|
* 02 12 22 2: [0] -> 0 --> send element (r+1)%p to node (r+1)%p
|
|
*
|
|
* *** round 1 ***
|
|
* 0 1 2
|
|
*
|
|
* 00+20 10 20 0: red(0), [0] -> 1
|
|
* 01 11+01 21 1: red(1), [1] -> 2
|
|
* 02 12 22+12 2: red(2), [2] -> 0 --> reduce and send element (r+0)%p to node (r+1)%p
|
|
*
|
|
* *** round 2 ***
|
|
* 0 1 2
|
|
*
|
|
* 00/20 all 20 0: red(2), [2] -> 1
|
|
* 01 11/01 all 1: red(0), [0] -> 2
|
|
* all 12 22/12 2: red(1), [1] -> 0 --> reduce and send (r-1)%p to node (r+1)%p
|
|
*
|
|
* *** round 3 ***
|
|
* 0 1 2
|
|
*
|
|
* 00/20 all all 0: [1] -> 1
|
|
* all 11/01 all 1: [2] -> 2
|
|
* all all 22/12 2: [0] -> 0 --> send element (r-2)%p to node (r+1)%p
|
|
*
|
|
* *** round 4 ***
|
|
* 0 1 2
|
|
*
|
|
* all all all 0: done
|
|
* all all all 1: done
|
|
* all all all 2: done
|
|
*
|
|
* -> 4
|
|
* *** round 0 ***
|
|
* 0 1 2 3
|
|
*
|
|
* 00 10 20 30 0: [1] -> 1
|
|
* 01 11 21 31 1: [2] -> 2
|
|
* 02 12 22 32 2: [3] -> 3
|
|
* 03 13 23 33 3: [0] -> 0 --> send element (r+1)%p to node (r+1)%p
|
|
*
|
|
* *** round 1 ***
|
|
* 0 1 2 3
|
|
*
|
|
* 00+30 10 20 30 0: red(0), [0] -> 1
|
|
* 01 11+01 21 31 1: red(1), [1] -> 2
|
|
* 02 12 22+12 32 2: red(2), [2] -> 3
|
|
* 03 13 23 33+23 3: red(3), [3] -> 0 --> reduce and send element (r+0)%p to node (r+1)%p
|
|
*
|
|
* *** round 2 ***
|
|
* 0 1 2 3
|
|
*
|
|
* 00/30 10+00/30 20 30 0: red(3), [3] -> 1
|
|
* 01 11/01 21+11/01 31 1: red(0), [0] -> 2
|
|
* 02 12 22/12 32+22/12 2: red(1), [1] -> 3
|
|
* 03+33/23 13 23 33/23 3: red(2), [2] -> 0 --> reduce and send (r-1)%p to node (r+1)%p
|
|
*
|
|
* *** round 3 ***
|
|
* 0 1 2 3
|
|
*
|
|
* 00/30 10/00/30 all 30 0: red(2), [2] -> 1
|
|
* 01 11/01 21/11/01 all 1: red(3), [3] -> 2
|
|
* all 12 22/12 32/22/12 2: red(0), [0] -> 3
|
|
* 03/33/23 all 23 33/23 3: red(1), [1] -> 0 --> reduce and send (r-2)%p to node (r+1)%p
|
|
*
|
|
* *** round 4 ***
|
|
* 0 1 2 3
|
|
*
|
|
* 00/30 10/00/30 all all 0: [1] -> 1
|
|
* all 11/01 21/11/01 all 1: [2] -> 2
|
|
* all all 22/12 32/22/12 2: [3] -> 3
|
|
* 03/33/23 all all 33/23 3: [0] -> 0 --> receive and send element (r+1)%p to node (r+1)%p
|
|
*
|
|
* *** round 5 ***
|
|
* 0 1 2 3
|
|
*
|
|
* all 10/00/30 all all 0: [0] -> 1
|
|
* all all 21/11/01 all 1: [1] -> 2
|
|
* all all all 32/22/12 2: [3] -> 3
|
|
* 03/33/23 all all all 3: [4] -> 4 --> receive and send element (r-0)%p to node (r+1)%p
|
|
*
|
|
* *** round 6 ***
|
|
* 0 1 2 3
|
|
*
|
|
* all all all all
|
|
* all all all all
|
|
* all all all all
|
|
* all all all all receive element (r-1)%p
|
|
*
|
|
* 2p-2 rounds ... every node does p-1 reductions and p-1 sends
|
|
*
|
|
*/
|
|
/* first p-1 rounds are reductions */
|
|
for (int round = 0 ; round < p - 1 ; ++round) {
|
|
int selement = (r+1-round + 2*p /*2*p avoids negative mod*/)%p; /* the element I am sending */
|
|
int soffset = segoffsets[selement]*ext;
|
|
int relement = (r-round + 2*p /*2*p avoids negative mod*/)%p; /* the element that I receive from my neighbor */
|
|
int roffset = segoffsets[relement]*ext;
|
|
|
|
/* first message come out of sendbuf */
|
|
if (round == 0) {
|
|
res = NBC_Sched_send ((char *) sendbuf + soffset, false, segsizes[selement], datatype, speer,
|
|
schedule, false);
|
|
} else {
|
|
res = NBC_Sched_send ((char *) recvbuf + soffset, false, segsizes[selement], datatype, speer,
|
|
schedule, false);
|
|
}
|
|
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
break;
|
|
}
|
|
|
|
res = NBC_Sched_recv ((char *) recvbuf + roffset, false, segsizes[relement], datatype, rpeer,
|
|
schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
break;
|
|
}
|
|
|
|
res = NBC_Sched_op ((char *) sendbuf + roffset, false, (char *) recvbuf + roffset, false,
|
|
segsizes[relement], datatype, op, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
free (segsizes);
|
|
free (segoffsets);
|
|
return res;
|
|
}
|
|
|
|
for (int round = p - 1 ; round < 2 * p - 2 ; ++round) {
|
|
int selement = (r+1-round + 2*p /*2*p avoids negative mod*/)%p; /* the element I am sending */
|
|
int soffset = segoffsets[selement]*ext;
|
|
int relement = (r-round + 2*p /*2*p avoids negative mod*/)%p; /* the element that I receive from my neighbor */
|
|
int roffset = segoffsets[relement]*ext;
|
|
|
|
res = NBC_Sched_send ((char *) recvbuf + soffset, false, segsizes[selement], datatype, speer,
|
|
schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
break;
|
|
}
|
|
|
|
res = NBC_Sched_recv ((char *) recvbuf + roffset, false, segsizes[relement], datatype, rpeer,
|
|
schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
free (segsizes);
|
|
free (segoffsets);
|
|
|
|
return res;
|
|
}
|
|
|
|
static inline int allred_sched_linear(int rank, int rsize, const void *sendbuf, void *recvbuf, int count, MPI_Datatype datatype,
|
|
ptrdiff_t gap, MPI_Op op, int ext, int size, NBC_Schedule *schedule, void *tmpbuf) {
|
|
int res;
|
|
|
|
if (0 == count) {
|
|
return OMPI_SUCCESS;
|
|
}
|
|
|
|
/* send my data to the remote root */
|
|
res = NBC_Sched_send (sendbuf, false, count, datatype, 0, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
|
|
/* recv my data to the remote root */
|
|
if (0 != rank || 1 ==(rsize%2)) {
|
|
res = NBC_Sched_recv (recvbuf, false, count, datatype, 0, schedule, false);
|
|
} else {
|
|
res = NBC_Sched_recv ((void *)(-gap), true, count, datatype, 0, schedule, false);
|
|
}
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
|
|
if (0 == rank) {
|
|
char *rbuf, *lbuf, *buf;
|
|
int tmprbuf, tmplbuf;
|
|
|
|
res = NBC_Sched_barrier (schedule);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
|
|
/* ensure the result ends up in recvbuf */
|
|
if (0 == (rsize%2)) {
|
|
lbuf = (void *)(-gap);
|
|
tmplbuf = true;
|
|
rbuf = recvbuf;
|
|
tmprbuf = false;
|
|
} else {
|
|
rbuf = (void *)(-gap);
|
|
tmprbuf = true;
|
|
lbuf = recvbuf;
|
|
tmplbuf = false;
|
|
}
|
|
|
|
/* get data from remote peers and reduce */
|
|
for (int rpeer = 1 ; rpeer < rsize ; ++rpeer) {
|
|
res = NBC_Sched_recv (rbuf, tmprbuf, count, datatype, rpeer, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
|
|
res = NBC_Sched_op (lbuf, tmplbuf, rbuf, tmprbuf, count, datatype, op, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
/* swap left and right buffers */
|
|
buf = rbuf; rbuf = lbuf ; lbuf = buf;
|
|
tmprbuf ^= 1; tmplbuf ^= 1;
|
|
}
|
|
|
|
/* exchange our result with the remote root (each root will broadcast to the other's peers) */
|
|
res = NBC_Sched_recv ((void *)(-gap), true, count, datatype, 0, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
|
|
/* wait for data from remote root */
|
|
res = NBC_Sched_send (recvbuf, false, count, datatype, 0, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
|
|
/* broadcast the result to all remote peers */
|
|
for (int rpeer = 1 ; rpeer < rsize ; ++rpeer) {
|
|
res = NBC_Sched_send ((void *)(-gap), true, count, datatype, rpeer, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
}
|
|
}
|
|
|
|
return OMPI_SUCCESS;
|
|
}
|
|
|
|
/*
|
|
* allred_sched_redscat_allgather:
|
|
*
|
|
* Description: an implementation of Rabenseifner's Allreduce algorithm [1, 2].
|
|
* [1] Rajeev Thakur, Rolf Rabenseifner and William Gropp.
|
|
* Optimization of Collective Communication Operations in MPICH //
|
|
* The Int. Journal of High Performance Computing Applications. Vol 19,
|
|
* Issue 1, pp. 49--66.
|
|
* [2] http://www.hlrs.de/mpi/myreduce.html.
|
|
*
|
|
* This algorithm is a combination of a reduce-scatter implemented with
|
|
* recursive vector halving and recursive distance doubling, followed either
|
|
* by an allgather implemented with recursive doubling.
|
|
*
|
|
* Step 1. If the number of processes is not a power of two, reduce it to
|
|
* the nearest lower power of two (p' = 2^{\floor{\log_2 p}})
|
|
* by removing r = p - p' extra processes as follows. In the first 2r processes
|
|
* (ranks 0 to 2r - 1), all the even ranks send the second half of the input
|
|
* vector to their right neighbor (rank + 1), and all the odd ranks send
|
|
* the first half of the input vector to their left neighbor (rank - 1).
|
|
* The even ranks compute the reduction on the first half of the vector and
|
|
* the odd ranks compute the reduction on the second half. The odd ranks then
|
|
* send the result to their left neighbors (the even ranks). As a result,
|
|
* the even ranks among the first 2r processes now contain the reduction with
|
|
* the input vector on their right neighbors (the odd ranks). These odd ranks
|
|
* do not participate in the rest of the algorithm, which leaves behind
|
|
* a power-of-two number of processes. The first r even-ranked processes and
|
|
* the last p - 2r processes are now renumbered from 0 to p' - 1.
|
|
*
|
|
* Step 2. The remaining processes now perform a reduce-scatter by using
|
|
* recursive vector halving and recursive distance doubling. The even-ranked
|
|
* processes send the second half of their buffer to rank + 1 and the odd-ranked
|
|
* processes send the first half of their buffer to rank - 1. All processes
|
|
* then compute the reduction between the local buffer and the received buffer.
|
|
* In the next log_2(p') - 1 steps, the buffers are recursively halved, and the
|
|
* distance is doubled. At the end, each of the p' processes has 1 / p' of the
|
|
* total reduction result.
|
|
*
|
|
* Step 3. An allgather is performed by using recursive vector doubling and
|
|
* distance halving. All exchanges are executed in reverse order relative
|
|
* to recursive doubling on previous step. If the number of processes is not
|
|
* a power of two, the total result vector must be sent to the r processes
|
|
* that were removed in the first step.
|
|
*
|
|
* Limitations:
|
|
* count >= 2^{\floor{\log_2 p}}
|
|
* commutative operations only
|
|
* intra-communicators only
|
|
*
|
|
* Memory requirements (per process):
|
|
* count * typesize + 4 * \log_2(p) * sizeof(int) = O(count)
|
|
*
|
|
* Schedule length (rounds): O(\log(p))
|
|
*/
|
|
static inline int allred_sched_redscat_allgather(
|
|
int rank, int comm_size, int count, MPI_Datatype datatype, ptrdiff_t gap,
|
|
const void *sbuf, void *rbuf, MPI_Op op, char inplace,
|
|
NBC_Schedule *schedule, void *tmpbuf, struct ompi_communicator_t *comm)
|
|
{
|
|
int res = OMPI_SUCCESS;
|
|
int *rindex = NULL, *rcount = NULL, *sindex = NULL, *scount = NULL;
|
|
/* Find nearest power-of-two less than or equal to comm_size */
|
|
int nsteps = opal_hibit(comm_size, comm->c_cube_dim + 1); /* ilog2(comm_size) */
|
|
int nprocs_pof2 = 1 << nsteps; /* flp2(comm_size) */
|
|
if (!inplace) {
|
|
res = NBC_Sched_copy((char *)sbuf, false, count, datatype,
|
|
rbuf, false, count, datatype, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
}
|
|
char *tmp_buf = (char *)tmpbuf - gap;
|
|
ptrdiff_t lb, extent;
|
|
ompi_datatype_get_extent(datatype, &lb, &extent);
|
|
/*
|
|
* Step 1. Reduce the number of processes to the nearest lower power of two
|
|
* p' = 2^{\floor{\log_2 p}} by removing r = p - p' processes.
|
|
* 1. In the first 2r processes (ranks 0 to 2r - 1), all the even ranks send
|
|
* the second half of the input vector to their right neighbor (rank + 1)
|
|
* and all the odd ranks send the first half of the input vector to their
|
|
* left neighbor (rank - 1).
|
|
* 2. All 2r processes compute the reduction on their half.
|
|
* 3. The odd ranks then send the result to their left neighbors
|
|
* (the even ranks).
|
|
*
|
|
* The even ranks (0 to 2r - 1) now contain the reduction with the input
|
|
* vector on their right neighbors (the odd ranks). The first r even
|
|
* processes and the p - 2r last processes are renumbered from
|
|
* 0 to 2^{\floor{\log_2 p}} - 1.
|
|
*/
|
|
int vrank, step, wsize;
|
|
int nprocs_rem = comm_size - nprocs_pof2;
|
|
if (rank < 2 * nprocs_rem) {
|
|
int count_lhalf = count / 2;
|
|
int count_rhalf = count - count_lhalf;
|
|
if (rank % 2 != 0) {
|
|
/*
|
|
* Odd process -- exchange with rank - 1
|
|
* Send the left half of the input vector to the left neighbor,
|
|
* Recv the right half of the input vector from the left neighbor
|
|
*/
|
|
res = NBC_Sched_send(rbuf, false, count_lhalf, datatype, rank - 1,
|
|
schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
res = NBC_Sched_recv(tmp_buf + (ptrdiff_t)count_lhalf * extent,
|
|
false, count_rhalf, datatype, rank - 1, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
res = NBC_Sched_op(tmp_buf + (ptrdiff_t)count_lhalf * extent,
|
|
false, (char *)rbuf + (ptrdiff_t)count_lhalf * extent,
|
|
false, count_rhalf, datatype, op, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
/* Send the right half to the left neighbor */
|
|
res = NBC_Sched_send((char *)rbuf + (ptrdiff_t)count_lhalf * extent,
|
|
false, count_rhalf, datatype, rank - 1, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
/* This process does not participate in recursive doubling phase */
|
|
vrank = -1;
|
|
} else {
|
|
/*
|
|
* Even process -- exchange with rank + 1
|
|
* Send the right half of the input vector to the right neighbor,
|
|
* Recv the left half of the input vector from the right neighbor
|
|
*/
|
|
res = NBC_Sched_send((char *)rbuf + (ptrdiff_t)count_lhalf * extent,
|
|
false, count_rhalf, datatype, rank + 1, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
res = NBC_Sched_recv(tmp_buf, false, count_lhalf, datatype, rank + 1,
|
|
schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
res = NBC_Sched_op(tmp_buf, false, rbuf, false, count_lhalf,
|
|
datatype, op, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
/* Recv the right half from the right neighbor */
|
|
res = NBC_Sched_recv((char *)rbuf + (ptrdiff_t)count_lhalf * extent,
|
|
false, count_rhalf, datatype, rank + 1, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
vrank = rank / 2;
|
|
}
|
|
} else { /* rank >= 2 * nprocs_rem */
|
|
vrank = rank - nprocs_rem;
|
|
}
|
|
/*
|
|
* Step 2. Reduce-scatter implemented with recursive vector halving and
|
|
* recursive distance doubling. We have p' = 2^{\floor{\log_2 p}}
|
|
* power-of-two number of processes with new ranks (vrank) and result in rbuf.
|
|
*
|
|
* The even-ranked processes send the right half of their buffer to rank + 1
|
|
* and the odd-ranked processes send the left half of their buffer to
|
|
* rank - 1. All processes then compute the reduction between the local
|
|
* buffer and the received buffer. In the next \log_2(p') - 1 steps, the
|
|
* buffers are recursively halved, and the distance is doubled. At the end,
|
|
* each of the p' processes has 1 / p' of the total reduction result.
|
|
*/
|
|
rindex = malloc(sizeof(*rindex) * nsteps);
|
|
sindex = malloc(sizeof(*sindex) * nsteps);
|
|
rcount = malloc(sizeof(*rcount) * nsteps);
|
|
scount = malloc(sizeof(*scount) * nsteps);
|
|
if (NULL == rindex || NULL == sindex || NULL == rcount || NULL == scount) {
|
|
res = OMPI_ERR_OUT_OF_RESOURCE;
|
|
goto cleanup_and_return;
|
|
}
|
|
if (vrank != -1) {
|
|
step = 0;
|
|
wsize = count;
|
|
sindex[0] = rindex[0] = 0;
|
|
for (int mask = 1; mask < nprocs_pof2; mask <<= 1) {
|
|
/*
|
|
* On each iteration: rindex[step] = sindex[step] -- begining of the
|
|
* current window. Length of the current window is storded in wsize.
|
|
*/
|
|
int vdest = vrank ^ mask;
|
|
/* Translate vdest virtual rank to real rank */
|
|
int dest = (vdest < nprocs_rem) ? vdest * 2 : vdest + nprocs_rem;
|
|
if (rank < dest) {
|
|
/*
|
|
* Recv into the left half of the current window, send the right
|
|
* half of the window to the peer (perform reduce on the left
|
|
* half of the current window)
|
|
*/
|
|
rcount[step] = wsize / 2;
|
|
scount[step] = wsize - rcount[step];
|
|
sindex[step] = rindex[step] + rcount[step];
|
|
} else {
|
|
/*
|
|
* Recv into the right half of the current window, send the left
|
|
* half of the window to the peer (perform reduce on the right
|
|
* half of the current window)
|
|
*/
|
|
scount[step] = wsize / 2;
|
|
rcount[step] = wsize - scount[step];
|
|
rindex[step] = sindex[step] + scount[step];
|
|
}
|
|
/* Send part of data from the rbuf, recv into the tmp_buf */
|
|
res = NBC_Sched_send((char *)rbuf + (ptrdiff_t)sindex[step] * extent,
|
|
false, scount[step], datatype, dest, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
res = NBC_Sched_recv((char *)tmp_buf + (ptrdiff_t)rindex[step] * extent,
|
|
false, rcount[step], datatype, dest, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
/* Local reduce: rbuf[] = tmp_buf[] <op> rbuf[] */
|
|
res = NBC_Sched_op((char *)tmp_buf + (ptrdiff_t)rindex[step] * extent,
|
|
false, (char *)rbuf + (ptrdiff_t)rindex[step] * extent,
|
|
false, rcount[step], datatype, op, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
/* Move the current window to the received message */
|
|
if (step + 1 < nsteps) {
|
|
rindex[step + 1] = rindex[step];
|
|
sindex[step + 1] = rindex[step];
|
|
wsize = rcount[step];
|
|
step++;
|
|
}
|
|
}
|
|
/*
|
|
* Assertion: each process has 1 / p' of the total reduction result:
|
|
* rcount[nsteps - 1] elements in the rbuf[rindex[nsteps - 1], ...].
|
|
*/
|
|
/*
|
|
* Step 3. Allgather by the recursive doubling algorithm.
|
|
* Each process has 1 / p' of the total reduction result:
|
|
* rcount[nsteps - 1] elements in the rbuf[rindex[nsteps - 1], ...].
|
|
* All exchanges are executed in reverse order relative
|
|
* to recursive doubling (previous step).
|
|
*/
|
|
step = nsteps - 1;
|
|
for (int mask = nprocs_pof2 >> 1; mask > 0; mask >>= 1) {
|
|
int vdest = vrank ^ mask;
|
|
/* Translate vdest virtual rank to real rank */
|
|
int dest = (vdest < nprocs_rem) ? vdest * 2 : vdest + nprocs_rem;
|
|
/*
|
|
* Send rcount[step] elements from rbuf[rindex[step]...]
|
|
* Recv scount[step] elements to rbuf[sindex[step]...]
|
|
*/
|
|
res = NBC_Sched_send((char *)rbuf + (ptrdiff_t)rindex[step] * extent,
|
|
false, rcount[step], datatype, dest, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
res = NBC_Sched_recv((char *)rbuf + (ptrdiff_t)sindex[step] * extent,
|
|
false, scount[step], datatype, dest, schedule, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
step--;
|
|
}
|
|
}
|
|
/*
|
|
* Step 4. Send total result to excluded odd ranks.
|
|
*/
|
|
if (rank < 2 * nprocs_rem) {
|
|
if (rank % 2 != 0) {
|
|
/* Odd process -- recv result from rank - 1 */
|
|
res = NBC_Sched_recv(rbuf, false, count, datatype, rank - 1, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
} else {
|
|
/* Even process -- send result to rank + 1 */
|
|
res = NBC_Sched_send(rbuf, false, count, datatype, rank + 1, schedule, false);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) { goto cleanup_and_return; }
|
|
}
|
|
}
|
|
cleanup_and_return:
|
|
if (NULL != rindex)
|
|
free(rindex);
|
|
if (NULL != sindex)
|
|
free(sindex);
|
|
if (NULL != rcount)
|
|
free(rcount);
|
|
if (NULL != scount)
|
|
free(scount);
|
|
return res;
|
|
}
|
|
|
|
int ompi_coll_libnbc_allreduce_init(const void* sendbuf, void* recvbuf, int count, MPI_Datatype datatype, MPI_Op op,
|
|
struct ompi_communicator_t *comm, MPI_Info info, ompi_request_t ** request,
|
|
struct mca_coll_base_module_2_3_0_t *module) {
|
|
int res = nbc_allreduce_init(sendbuf, recvbuf, count, datatype, op,
|
|
comm, request, module, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
|
|
return OMPI_SUCCESS;
|
|
}
|
|
|
|
int ompi_coll_libnbc_allreduce_inter_init(const void* sendbuf, void* recvbuf, int count, MPI_Datatype datatype, MPI_Op op,
|
|
struct ompi_communicator_t *comm, MPI_Info info, ompi_request_t ** request,
|
|
struct mca_coll_base_module_2_3_0_t *module) {
|
|
int res = nbc_allreduce_inter_init(sendbuf, recvbuf, count, datatype, op,
|
|
comm, request, module, true);
|
|
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
|
|
return res;
|
|
}
|
|
|
|
return OMPI_SUCCESS;
|
|
}
|