+++ /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"
-
-static int bcast_NTSL_segment_size_in_byte = 8192;
-
-/* Non-topology-specific pipelined linear-bcast function
- 0->1, 1->2 ,2->3, ....., ->last node : in a pipeline fashion
-*/
-int smpi_coll_tuned_bcast_NTSL_Isend(void *buf, int count, MPI_Datatype datatype,
- int root, MPI_Comm comm)
-{
- int tag = COLL_TAG_BCAST;
- MPI_Status status;
- MPI_Request request;
- MPI_Request *send_request_array;
- MPI_Request *recv_request_array;
- MPI_Status *send_status_array;
- MPI_Status *recv_status_array;
- int rank, size;
- int i;
- MPI_Aint extent;
- extent = datatype->get_extent();
-
- rank = comm->rank();
- size = comm->size();
-
- /* source node and destination nodes (same through out the functions) */
- int to = (rank + 1) % size;
- int from = (rank + size - 1) % size;
-
- /* segment is segment size in number of elements (not bytes) */
- int segment = bcast_NTSL_segment_size_in_byte / extent;
- segment = segment == 0 ? 1 :segment;
- /* pipeline length */
- int pipe_length = count / segment;
-
- /* use for buffer offset for sending and receiving data = segment size in byte */
- int increment = segment * extent;
-
- /* if the input size is not divisible by segment size =>
- the small remainder will be done with native implementation */
- int remainder = count % segment;
-
- /* if root is not zero send to rank zero first
- this can be modified to make it faster by using logical src, dst.
- */
- if (root != 0) {
- if (rank == root) {
- Request::send(buf, count, datatype, 0, tag, comm);
- } else if (rank == 0) {
- Request::recv(buf, count, datatype, root, tag, comm, &status);
- }
- }
-
- /* when a message is smaller than a block size => no pipeline */
- if (count <= segment) {
- if (rank == 0) {
- Request::send(buf, count, datatype, to, tag, comm);
- } else if (rank == (size - 1)) {
- request = Request::irecv(buf, count, datatype, from, tag, comm);
- Request::wait(&request, &status);
- } else {
- request = Request::irecv(buf, count, datatype, from, tag, comm);
- Request::wait(&request, &status);
- Request::send(buf, count, datatype, to, tag, comm);
- }
- return MPI_SUCCESS;
- }
-
- /* pipeline bcast */
- else {
- send_request_array =
- (MPI_Request *) xbt_malloc((size + pipe_length) * sizeof(MPI_Request));
- recv_request_array =
- (MPI_Request *) xbt_malloc((size + pipe_length) * sizeof(MPI_Request));
- send_status_array =
- (MPI_Status *) xbt_malloc((size + pipe_length) * sizeof(MPI_Status));
- recv_status_array =
- (MPI_Status *) xbt_malloc((size + pipe_length) * sizeof(MPI_Status));
-
- /* root send data */
- if (rank == 0) {
- for (i = 0; i < pipe_length; i++) {
- send_request_array[i] = Request::isend((char *) buf + (i * increment), segment, datatype, to,
- (tag + i), comm);
- }
- Request::waitall((pipe_length), send_request_array, send_status_array);
- }
-
- /* last node only receive data */
- else if (rank == (size - 1)) {
- for (i = 0; i < pipe_length; i++) {
- recv_request_array[i] = Request::irecv((char *) buf + (i * increment), segment, datatype, from,
- (tag + i), comm);
- }
- Request::waitall((pipe_length), recv_request_array, recv_status_array);
- }
-
- /* intermediate nodes relay (receive, then send) data */
- else {
- for (i = 0; i < pipe_length; i++) {
- recv_request_array[i] = Request::irecv((char *) buf + (i * increment), segment, datatype, from,
- (tag + i), comm);
- }
- for (i = 0; i < pipe_length; i++) {
- Request::wait(&recv_request_array[i], &status);
- send_request_array[i] = Request::isend((char *) buf + (i * increment), segment, datatype, to,
- (tag + i), comm);
- }
- Request::waitall((pipe_length), send_request_array, send_status_array);
- }
-
- free(send_request_array);
- free(recv_request_array);
- free(send_status_array);
- free(recv_status_array);
- } /* end pipeline */
-
- /* when count is not divisible by block size, use default BCAST for the remainder */
- if ((remainder != 0) && (count > segment)) {
- XBT_WARN("MPI_bcast_NTSL_Isend_nb use default MPI_bcast.");
- smpi_mpi_bcast((char *) buf + (pipe_length * increment), remainder, datatype,
- root, comm);
- }
-
- return MPI_SUCCESS;
-}
