+++ /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"
-#include <math.h>
-
-/*****************************************************************************
-
- * Function: alltoall_2dmesh_shoot
-
- * Return: int
-
- * Inputs:
- send_buff: send input buffer
- send_count: number of elements to send
- send_type: data type of elements being sent
- recv_buff: receive output buffer
- recv_count: number of elements to received
- recv_type: data type of elements being received
- comm: communicator
-
- * Descrp: Function realizes the alltoall operation using the 2dmesh
- algorithm. It actually performs allgather operation in x dimension
- then in the y dimension. Each node then extracts the needed data.
- The communication in each dimension follows "simple."
-
- * Auther: Ahmad Faraj
-
-****************************************************************************/
-static int alltoall_check_is_2dmesh(int num, int *i, int *j)
-{
- int x, max = num / 2;
- x = sqrt(num);
-
- while (x <= max) {
- if ((num % x) == 0) {
- *i = x;
- *j = num / x;
-
- if (*i > *j) {
- x = *i;
- *i = *j;
- *j = x;
- }
-
- return 1;
- }
- x++;
- }
- return 0;
-}
-
-int smpi_coll_tuned_alltoall_2dmesh(void *send_buff, int send_count,
- MPI_Datatype send_type,
- void *recv_buff, int recv_count,
- MPI_Datatype recv_type, MPI_Comm comm)
-{
- MPI_Status *statuses, s;
- MPI_Request *reqs, *req_ptr;;
- MPI_Aint extent;
-
- char *tmp_buff1, *tmp_buff2;
- int i, j, src, dst, rank, num_procs, count, num_reqs;
- int X, Y, send_offset, recv_offset;
- int my_row_base, my_col_base, src_row_base, block_size;
- int tag = COLL_TAG_ALLTOALL;
-
- rank = smpi_comm_rank(comm);
- num_procs = smpi_comm_size(comm);
- extent = smpi_datatype_get_extent(send_type);
-
- if (!alltoall_check_is_2dmesh(num_procs, &X, &Y))
- return MPI_ERR_OTHER;
-
- my_row_base = (rank / Y) * Y;
- my_col_base = rank % Y;
-
- block_size = extent * send_count;
-
- tmp_buff1 = (char *) smpi_get_tmp_sendbuffer(block_size * num_procs * Y);
- tmp_buff2 = (char *) smpi_get_tmp_recvbuffer(block_size * Y);
-
- num_reqs = X;
- if (Y > X)
- num_reqs = Y;
-
- statuses = (MPI_Status *) xbt_malloc(num_reqs * sizeof(MPI_Status));
- reqs = (MPI_Request *) xbt_malloc(num_reqs * sizeof(MPI_Request));
-
- req_ptr = reqs;
-
- count = send_count * num_procs;
-
- for (i = 0; i < Y; i++) {
- src = i + my_row_base;
- if (src == rank)
- continue;
-
- recv_offset = (src % Y) * block_size * num_procs;
- *(req_ptr++) = smpi_mpi_irecv(tmp_buff1 + recv_offset, count, recv_type, src, tag, comm);
- }
-
- for (i = 0; i < Y; i++) {
- dst = i + my_row_base;
- if (dst == rank)
- continue;
- smpi_mpi_send(send_buff, count, send_type, dst, tag, comm);
- }
-
- smpi_mpi_waitall(Y - 1, reqs, statuses);
- req_ptr = reqs;
-
- for (i = 0; i < Y; i++) {
- send_offset = (rank * block_size) + (i * block_size * num_procs);
- recv_offset = (my_row_base * block_size) + (i * block_size);
-
- if (i + my_row_base == rank)
- smpi_mpi_sendrecv((char *) send_buff + recv_offset, send_count, send_type,
- rank, tag,
- (char *) recv_buff + recv_offset, recv_count, recv_type,
- rank, tag, comm, &s);
-
- else
- smpi_mpi_sendrecv(tmp_buff1 + send_offset, send_count, send_type,
- rank, tag,
- (char *) recv_buff + recv_offset, recv_count, recv_type,
- rank, tag, comm, &s);
- }
-
-
- for (i = 0; i < X; i++) {
- src = (i * Y + my_col_base);
- if (src == rank)
- continue;
- src_row_base = (src / Y) * Y;
-
- *(req_ptr++) = smpi_mpi_irecv((char *) recv_buff + src_row_base * block_size, recv_count * Y,
- recv_type, src, tag, comm);
- }
-
- for (i = 0; i < X; i++) {
- dst = (i * Y + my_col_base);
- if (dst == rank)
- continue;
-
- recv_offset = 0;
- for (j = 0; j < Y; j++) {
- send_offset = (dst + j * num_procs) * block_size;
-
- if (j + my_row_base == rank)
- smpi_mpi_sendrecv((char *) send_buff + dst * block_size, send_count,
- send_type, rank, tag, tmp_buff2 + recv_offset, recv_count,
- recv_type, rank, tag, comm, &s);
- else
- smpi_mpi_sendrecv(tmp_buff1 + send_offset, send_count, send_type,
- rank, tag,
- tmp_buff2 + recv_offset, recv_count, recv_type,
- rank, tag, comm, &s);
-
- recv_offset += block_size;
- }
-
- smpi_mpi_send(tmp_buff2, send_count * Y, send_type, dst, tag, comm);
- }
- smpi_mpi_waitall(X - 1, reqs, statuses);
- free(reqs);
- free(statuses);
- smpi_free_tmp_buffer(tmp_buff1);
- smpi_free_tmp_buffer(tmp_buff2);
- return MPI_SUCCESS;
-}
