+++ /dev/null
-/* Copyright (c) 2013-2014. The SimGrid Team.
- * All rights reserved. */
-
-/* This program is free software; you can redistribute it and/or modify it
- * under the terms of the license (GNU LGPL) which comes with this package. */
-
-#include "colls_private.h"
-/* IMPLEMENTED BY PITCH PATARASUK
- Non-topoloty-specific (however, number of cores/node need to be changed)
- all-reduce operation designed for smp clusters
- It uses 2-layer communication: binomial for intra-communication
- and rdb for inter-communication*/
-
-
-/* ** NOTE **
- Use -DMPICH2 if this code does not compile.
- MPICH1 code also work on MPICH2 on our cluster and the performance are similar.
- This code assume commutative and associative reduce operator (MPI_SUM, MPI_MAX, etc).
-*/
-
-//#include <star-reduction.c>
-
-/*
-This fucntion performs all-reduce operation as follow.
-1) binomial_tree reduce inside each SMP node
-2) Recursive doubling intra-communication between root of each SMP node
-3) binomial_tree bcast inside each SMP node
-*/
-int smpi_coll_tuned_allreduce_smp_rdb(void *send_buf, void *recv_buf, int count,
- MPI_Datatype dtype, MPI_Op op,
- MPI_Comm comm)
-{
- int comm_size, rank;
- void *tmp_buf;
- int tag = COLL_TAG_ALLREDUCE;
- int mask, src, dst;
- MPI_Status status;
- if(smpi_comm_get_leaders_comm(comm)==MPI_COMM_NULL){
- smpi_comm_init_smp(comm);
- }
- int num_core=1;
- if (smpi_comm_is_uniform(comm)){
- num_core = smpi_comm_size(smpi_comm_get_intra_comm(comm));
- }
- /*
- #ifdef MPICH2_REDUCTION
- MPI_User_function * uop = MPIR_Op_table[op % 16 - 1];
- #else
- MPI_User_function *uop;
- struct MPIR_OP *op_ptr;
- op_ptr = MPIR_ToPointer(op);
- uop = op_ptr->op;
- #endif
- */
- comm_size = smpi_comm_size(comm);
- rank = smpi_comm_rank(comm);
- MPI_Aint extent;
- extent = smpi_datatype_get_extent(dtype);
- tmp_buf = (void *) smpi_get_tmp_sendbuffer(count * extent);
-
- /* compute intra and inter ranking */
- int intra_rank, inter_rank;
- intra_rank = rank % num_core;
- inter_rank = rank / num_core;
-
- /* size of processes participate in intra communications =>
- should be equal to number of machines */
- int inter_comm_size = (comm_size + num_core - 1) / num_core;
-
- /* copy input buffer to output buffer */
- smpi_mpi_sendrecv(send_buf, count, dtype, rank, tag,
- recv_buf, count, dtype, rank, tag, comm, &status);
-
- /* start binomial reduce intra communication inside each SMP node */
- mask = 1;
- while (mask < num_core) {
- if ((mask & intra_rank) == 0) {
- src = (inter_rank * num_core) + (intra_rank | mask);
- if (src < comm_size) {
- smpi_mpi_recv(tmp_buf, count, dtype, src, tag, comm, &status);
- smpi_op_apply(op, tmp_buf, recv_buf, &count, &dtype);
- }
- } else {
- dst = (inter_rank * num_core) + (intra_rank & (~mask));
- smpi_mpi_send(recv_buf, count, dtype, dst, tag, comm);
- break;
- }
- mask <<= 1;
- } /* end binomial reduce intra-communication */
-
-
- /* start rdb (recursive doubling) all-reduce inter-communication
- between each SMP nodes : each node only have one process that can communicate
- to other nodes */
- if (intra_rank == 0) {
-
- /* find nearest power-of-two less than or equal to inter_comm_size */
- int pof2, rem, newrank, newdst;
- pof2 = 1;
- while (pof2 <= inter_comm_size)
- pof2 <<= 1;
- pof2 >>= 1;
- rem = inter_comm_size - pof2;
-
- /* In the non-power-of-two case, all even-numbered
- processes of rank < 2*rem send their data to
- (rank+1). These even-numbered processes no longer
- participate in the algorithm until the very end.
- */
- if (inter_rank < 2 * rem) {
- if (inter_rank % 2 == 0) {
- dst = rank + num_core;
- smpi_mpi_send(recv_buf, count, dtype, dst, tag, comm);
- newrank = -1;
- } else {
- src = rank - num_core;
- smpi_mpi_recv(tmp_buf, count, dtype, src, tag, comm, &status);
- smpi_op_apply(op, tmp_buf, recv_buf, &count, &dtype);
- newrank = inter_rank / 2;
- }
- } else {
- newrank = inter_rank - rem;
- }
-
- /* example inter-communication RDB rank change algorithm
- 0,4,8,12..36 <= true rank (assume 4 core per SMP)
- 0123 4567 89 <= inter_rank
- 1 3 4567 89 (1,3 got data from 0,2 : 0,2 will be idle until the end)
- 0 1 4567 89
- 0 1 2345 67 => newrank
- */
-
- if (newrank != -1) {
- mask = 1;
- while (mask < pof2) {
- newdst = newrank ^ mask;
- /* find real rank of dest */
- dst = (newdst < rem) ? newdst * 2 + 1 : newdst + rem;
- dst *= num_core;
-
- /* exchange data in rdb manner */
- smpi_mpi_sendrecv(recv_buf, count, dtype, dst, tag, tmp_buf, count, dtype,
- dst, tag, comm, &status);
- smpi_op_apply(op, tmp_buf, recv_buf, &count, &dtype);
- mask <<= 1;
- }
- }
-
- /* non pof2 case
- left-over processes (all even ranks: < 2 * rem) get the result
- */
- if (inter_rank < 2 * rem) {
- if (inter_rank % 2) {
- smpi_mpi_send(recv_buf, count, dtype, rank - num_core, tag, comm);
- } else {
- smpi_mpi_recv(recv_buf, count, dtype, rank + num_core, tag, comm, &status);
- }
- }
- }
-
- /* start binomial broadcast intra-communication inside each SMP nodes */
- int num_core_in_current_smp = num_core;
- if (inter_rank == (inter_comm_size - 1)) {
- num_core_in_current_smp = comm_size - (inter_rank * num_core);
- }
- mask = 1;
- while (mask < num_core_in_current_smp) {
- if (intra_rank & mask) {
- src = (inter_rank * num_core) + (intra_rank - mask);
- smpi_mpi_recv(recv_buf, count, dtype, src, tag, comm, &status);
- break;
- }
- mask <<= 1;
- }
- mask >>= 1;
-
- while (mask > 0) {
- dst = (inter_rank * num_core) + (intra_rank + mask);
- if (dst < comm_size) {
- smpi_mpi_send(recv_buf, count, dtype, dst, tag, comm);
- }
- mask >>= 1;
- }
-
- smpi_free_tmp_buffer(tmp_buf);
- return MPI_SUCCESS;
-}
