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openmpi/src/mca/coll/hierarch/coll_hierarch_bcast.c

414 строки
12 KiB
C

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University.
* All rights reserved.
* Copyright (c) 2004-2005 The Trustees of the University of Tennessee.
* All rights reserved.
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
* University of Stuttgart. All rights reserved.
* Copyright (c) 2004-2005 The Regents of the University of California.
* All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "coll_hierarch.h"
#include "mpi.h"
#include "include/constants.h"
#include "util/output.h"
#include "mca/coll/coll.h"
#include "mca/coll/base/base.h"
#include "mca/coll/base/coll_tags.h"
#include "coll_hierarch.h"
#ifdef SIMPLE_HIERARCH
/*
* bcast_intra
*
* Function: - broadcast using O(N) algorithm
* Accepts: - same arguments as MPI_Bcast()
* Returns: - MPI_SUCCESS or error code
*/
int mca_coll_hierarch_bcast_intra(void *buff,
int count,
struct ompi_datatype_t *datatype,
int root,
struct ompi_communicator_t *comm)
{
struct mca_coll_base_comm_t *data=NULL;
struct ompi_communicator_t *llcomm=NULL;
int i, rank, ret;
rank = ompi_comm_rank ( comm );
data = comm->c_coll_selected_data;
llcomm = data->hier_llcomm;
/* trivial linear distribution of the data to all local leaders.
need something significantly better */
if ( rank == root ) {
for (i=0; i< data->hier_num_lleaders; i++) {
if ( data->hier_lleaders[i] == root ) {
data->hier_reqs[i] = MPI_REQUEST_NULL;
continue;
}
ret = mca_pml.pml_isend (buff, count, datatype, data->hier_lleaders[i],
MCA_COLL_BASE_TAG_BCAST,
MCA_PML_BASE_SEND_STANDARD,
comm, &(data->hier_reqs[i]));
if ( OMPI_SUCCESS != ret ) {
return ret;
}
}
ret = ompi_request_wait_all ( data->hier_num_lleaders, data->hier_reqs,
MPI_STATUSES_IGNORE);
if ( OMPI_SUCCESS != ret ) {
return ret;
}
}
if ( data->hier_am_lleader ) {
ret = mca_pml.pml_recv ( buff, count, datatype, root,
MCA_COLL_BASE_TAG_BCAST, comm,
MPI_STATUS_IGNORE );
if ( OMPI_SUCCESS != ret ) {
return ret;
}
}
/* once the local leaders got the data from the root, they can distribute
it to the processes in their local, low-leve communicator.
*/
if ( MPI_COMM_NULL != llcomm ) {
ret = llcomm->c_coll.coll_bcast(buff, count, datatype,
data->hier_my_lleader, llcomm );
}
return ret;
}
#else
static int mca_coll_hierarch_intra_segmented_bcast ( void* buffer,
int count,
ompi_datatype_t * datatype,
int root,
ompi_communicator_t * comm,
int segsize,
struct mca_coll_hierarch_topo *topo);
static int mca_coll_hierarch_intra_bcast_setup_topo (int count,
ompi_datatype_t *datatype,
int root,
struct mca_coll_base_comm_t *data,
int *segsize);
static void setup_topo_bmtree ( int root, struct mca_coll_base_comm_t *data );
int mca_coll_hierarch_bcast_intra(void *buff,
int count,
struct ompi_datatype_t *datatype,
int root,
struct ompi_communicator_t *comm)
{
struct mca_coll_base_comm_t *data=NULL;
struct ompi_communicator_t *llcomm=NULL;
int rank, ret;
int segsize;
rank = ompi_comm_rank ( comm );
data = comm->c_coll_selected_data;
llcomm = data->hier_llcomm;
if ( rank == root || data->hier_am_lleader ) {
/* this functions sets up the topology used in the segmented
bcast afterwards and determines the segment size. */
ret = mca_coll_hierarch_intra_bcast_setup_topo (count, datatype, root, data,
&segsize);
if ( OMPI_SUCCESS != ret ) {
return ret;
}
/* ok, do now the actual bcast. Hopefully, this routine will come
out of Jelena's collective module in the end. For the moment,
I've implemented it myself
*/
ret = mca_coll_hierarch_intra_segmented_bcast (buff, count,
datatype, root,
comm, segsize,
&(data->hier_topo));
if ( OMPI_SUCCESS != ret ) {
return ret;
}
}
/* once the local leaders got the data from the root, they can distribute
it to the processes in their local, low-leve communicator.
*/
if ( MPI_COMM_NULL != llcomm ) {
ret = llcomm->c_coll.coll_bcast(buff, count, datatype,
data->hier_my_lleader, llcomm );
}
return ret;
}
/*
* This is the mother of all segmented bcast algorithms of any type.
* Due to the general structure of the topo argument, you can use this function
* for any type of algorith - it just depends on the settings of topo.
*
* The implementation is strongly leaning on the implementation in FT-MPI.
*/
static int mca_coll_hierarch_intra_segmented_bcast ( void* buffer,
int count,
ompi_datatype_t * datatype,
int root,
ompi_communicator_t * comm,
int segsize,
struct mca_coll_hierarch_topo *topo)
{
int err=0, i, j;
int size, rank;
int segcount; /* Number of elements sent with each segment */
int num_segments; /* Number of segmenets */
int recvcount; /* the same like segcount, except for the last segment */
int typelng, realsegsize;
char *tmpbuf;
long rlb, ext;
ompi_request_t ** recv_request= NULL;
size = ompi_comm_size ( comm );
rank = ompi_comm_rank ( comm );
/* ------------------------------------------- */
/* special case for size == 1 and 2 */
if (size == 1) {
return OMPI_SUCCESS;
}
if (size == 2) {
if (rank == root) {
err = mca_pml.pml_send(buffer, count, datatype, (rank+1)%2,
MCA_COLL_BASE_TAG_BCAST,
MCA_PML_BASE_SEND_STANDARD, comm );
if ( OMPI_SUCCESS != err ) {
return err;
}
} else {
err = mca_pml.pml_recv(buffer, count, datatype, root,
MCA_COLL_BASE_TAG_BCAST, comm,
MPI_STATUS_IGNORE);
if ( OMPI_SUCCESS != err) {
return err;
}
}
return OMPI_SUCCESS;
}
/* end special case for size == 1 and 2 */
tmpbuf = (char *) buffer;
/* -------------------------------------------------- */
/* Determine number of segments and number of elements
sent per operation */
err = ompi_ddt_type_size( datatype, &typelng);
if ( OMPI_SUCCESS != err) {
return ( err );
}
if ( segsize > 0 ) {
segcount = segsize/typelng;
num_segments = count/segcount;
if (0 != (count % segcount)) {
num_segments++;
}
}
else {
segcount = count;
num_segments = 1;
}
/* Determine real segment size = segcount * extent */
err = ompi_ddt_get_extent( datatype, &rlb, &ext );
if ( OMPI_SUCCESS != err) {
return ( err );
}
realsegsize = segcount*ext;
/* ----------------------------------------------------- */
/* Post Irecv if not root-node */
if (rank != root) {
/* has a parent. need to receive before sending */
if ( num_segments > 2 * size ) {
recv_request = (MPI_Request*)malloc ( sizeof(ompi_request_t *)*num_segments );
}
else {
recv_request = comm->c_coll_selected_data->hier_reqs;
}
for( i = 0; i < num_segments; i++) {
if ( i == (num_segments -1) ) {
recvcount = count - (segcount * i);
}
else {
recvcount = segcount;
}
err = mca_pml.pml_irecv(tmpbuf+i*realsegsize, recvcount, datatype,
topo->topo_prev, MCA_COLL_BASE_TAG_BCAST,
comm, &recv_request[i]);
if ( OMPI_SUCCESS != err ) {
return ( err );
}
}
}
/* ---------------------------------------------- */
/* If leaf node, just finish the receive */
if (topo->topo_nextsize == 0) {
if(recv_request != NULL) {
err = ompi_request_wait_all (num_segments, recv_request, MPI_STATUSES_IGNORE);
if ( OMPI_SUCCESS != err ) {
return ( err );
}
}
}
else {
/* ------------------------------------------ */
/* root or intermediate node */
for( i = 0; i < num_segments; i++) {
if (rank != root) {
/* intermediate nodes have to wait for the completion of
the corresponding receive */
err = ompi_request_wait_all(1, &recv_request[i], MPI_STATUS_IGNORE);
if ( OMPI_SUCCESS != err ) {
return ( err );
}
}
for ( j = 0; j < topo->topo_nextsize; j++) {
if ( i == ( num_segments - 1 )) {
recvcount = count - ( segcount * i);
}
else {
recvcount = segcount;
}
err = mca_pml.pml_send(tmpbuf+i*realsegsize, recvcount,
datatype, topo->topo_next[j],
MCA_COLL_BASE_TAG_BCAST,
MCA_PML_BASE_SEND_STANDARD, comm );
if( OMPI_SUCCESS != err ) {
return ( err );
}
} /* for ( j = 0; j < topo_nextsize; j++) */
} /* for ( i = 0; i < num_segments; i++) */
}
if ( num_segments > 2 * size ) {
if(recv_request != NULL) {
free(recv_request);
}
}
return OMPI_SUCCESS;
}
/*
* This routine does the magic to determine, which topology (bmtree, linear, chain etc)
* would perform best in this scenario. At the moment, we just do bmtree.
*
* The implementation is once again strongly related to the version in FT-MPI.
*/
static int mca_coll_hierarch_intra_bcast_setup_topo (int count,
ompi_datatype_t *datatype,
int root,
struct mca_coll_base_comm_t *data,
int *segsize)
{
/* without spending time on that issues, I set for the moment segsize to 32k. */
*segsize = 32768;
/* without spending time on that issue, I set the topology to a binomial tree */
setup_topo_bmtree ( root, data );
return OMPI_SUCCESS;
}
static void setup_topo_bmtree ( int root, struct mca_coll_base_comm_t *data )
{
/* This implementation is based on the closest first bmtree algorithms
in FT-MPI implemnented by George/Jelena, has however a couple of
significant modifications:
- we are not having a contiguous list of participating processes,
but a list containing the ranks of the participating processes.
- if the root is not part of this list, we add him to the list
*/
int childs = 0;
int rank, size, mask=1;
int index, remote, found;
int rootpos;
struct mca_coll_hierarch_topo *topo=&(data->hier_topo);
MCA_COLL_HIERARCH_IS_ROOT_LLEADER (root, data->hier_lleaders,
data->hier_num_lleaders, found,
rootpos);
if (found) {
size = data->hier_num_lleaders;
}
else {
size = data->hier_num_lleaders + 1;
data->hier_lleaders[rootpos] = root;
}
rank = data->hier_my_lleader;
/* allocate the array of childprocesses, if not yet done */
if ( NULL == topo->topo_next && 0 == topo->topo_maxsize ) {
topo->topo_next = (int *) malloc (data->hier_num_lleaders+1 * sizeof(int));
if ( NULL != topo->topo_next ) {
return;
}
topo->topo_maxsize=data->hier_num_lleaders+1;
}
index = rank - rootpos;
if( index < 0 ) index += size;
while( mask <= index ) mask <<= 1;
/* Determine the rank of my father */
if( rootpos == rank ) {
topo->topo_prev = root;
}
else {
remote = (index ^ (mask >> 1)) + rootpos;
if( remote >= size ) {
remote -= size;
}
topo->topo_prev = data->hier_lleaders[remote];
}
/* And now let's fill my childs */
while( mask < size ) {
remote = (index ^ mask);
if( remote >= size ) break;
remote += rootpos;
if( remote >= size ) remote -= size;
topo->topo_next[childs] = data->hier_lleaders[remote];
mask <<= 1;
childs++;
}
topo->topo_nextsize = childs;
return;
}
#endif