1 /* Copyright (c) 2013-2014. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
7 #include "colls_private.h"
9 /*****************************************************************************
11 * Function: alltoall_pair
16 send_buff: send input buffer
17 send_count: number of elements to send
18 send_type: data type of elements being sent
19 recv_buff: receive output buffer
20 recv_count: number of elements to received
21 recv_type: data type of elements being received
24 * Descrp: Function works when P is power of two. In each phase of P - 1
25 phases, nodes in pair communicate their data.
29 ****************************************************************************/
31 int smpi_coll_tuned_alltoall_pair_rma(void *send_buff, int send_count, MPI_Datatype send_type,
32 void *recv_buff, int recv_count, MPI_Datatype recv_type,
36 MPI_Aint send_chunk, recv_chunk;
39 int i, dst, rank, num_procs;
41 char *send_ptr = (char *) send_buff;
43 rank = smpi_comm_rank(comm);
44 num_procs = smpi_comm_size(comm);
45 send_chunk = smpi_datatype_get_extent(send_type);
46 recv_chunk = smpi_datatype_get_extent(recv_type);
48 win=smpi_mpi_win_create(recv_buff, num_procs * recv_chunk * send_count, recv_chunk, 0,
50 send_chunk *= send_count;
51 recv_chunk *= recv_count;
53 smpi_mpi_win_fence(assert, win);
54 for (i = 0; i < num_procs; i++) {
56 smpi_mpi_put(send_ptr + dst * send_chunk, send_count, send_type, dst,
57 rank /* send_chunk*/, send_count, send_type, win);
59 smpi_mpi_win_fence(assert, win);
60 smpi_mpi_win_free(&win);
65 int smpi_coll_tuned_alltoall_pair(void *send_buff, int send_count,
66 MPI_Datatype send_type,
67 void *recv_buff, int recv_count,
68 MPI_Datatype recv_type, MPI_Comm comm)
71 MPI_Aint send_chunk, recv_chunk;
73 int i, src, dst, rank, num_procs;
74 int tag = COLL_TAG_ALLTOALL;
75 char *send_ptr = (char *) send_buff;
76 char *recv_ptr = (char *) recv_buff;
78 rank = smpi_comm_rank(comm);
79 num_procs = smpi_comm_size(comm);
81 if((num_procs&(num_procs-1)))
82 THROWF(arg_error,0, "alltoall pair algorithm can't be used with non power of two number of processes ! ");
84 send_chunk = smpi_datatype_get_extent(send_type);
85 recv_chunk = smpi_datatype_get_extent(recv_type);
87 send_chunk *= send_count;
88 recv_chunk *= recv_count;
90 for (i = 0; i < num_procs; i++) {
92 smpi_mpi_sendrecv(send_ptr + dst * send_chunk, send_count, send_type, dst, tag,
93 recv_ptr + src * recv_chunk, recv_count, recv_type, src, tag,