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openmpi/ompi/patterns/comm/allreduce.c
2015-06-23 20:59:57 -07:00

261 строка
9.4 KiB
C

/*
* Copyright (c) 2009-2012 Mellanox Technologies. All rights reserved.
* Copyright (c) 2009-2012 Oak Ridge National Laboratory. All rights reserved.
* Copyright (c) 2012 Los Alamos National Security, LLC.
* All rights reserved.
* Copyright (c) 2014 Research Organization for Information Science
* and Technology (RIST). All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
/** @file */
#include "ompi_config.h"
#include "ompi/constants.h"
#include "ompi/op/op.h"
#include "ompi/datatype/ompi_datatype.h"
#include "ompi/communicator/communicator.h"
#include "opal/include/opal/sys/atomic.h"
#include "ompi/mca/pml/pml.h"
#include "ompi/patterns/net/netpatterns.h"
#include "coll_ops.h"
#include "commpatterns.h"
/**
* All-reduce for contigous primitive types
*/
OMPI_DECLSPEC int comm_allreduce_pml(void *sbuf, void *rbuf, int count,
ompi_datatype_t *dtype, int my_rank_in_group,
struct ompi_op_t *op, int n_peers,int *ranks_in_comm,
ompi_communicator_t *comm)
{
/* local variables */
int rc=OMPI_SUCCESS,n_dts_per_buffer,n_data_segments,stripe_number;
int pair_rank,exchange,extra_rank;
netpatterns_pair_exchange_node_t my_exchange_node;
int count_processed,count_this_stripe;
size_t dt_size,dt_extent;
char scratch_bufers[2][MAX_TMP_BUFFER];
int send_buffer=0,recv_buffer=1;
char *sbuf_current, *rbuf_current;
ompi_request_t *requests[2];
/* get size of data needed - same layout as user data, so that
* we can apply the reudction routines directly on these buffers
*/
rc = opal_datatype_type_size((opal_datatype_t *)dtype, &dt_size);
if( OMPI_SUCCESS != rc ) {
goto Error;
}
rc = ompi_datatype_type_extent(dtype, (OPAL_PTRDIFF_TYPE *)&dt_extent);
if( OMPI_SUCCESS != rc ) {
goto Error;
}
/* 1 process special case */
if(1 == n_peers) {
/* place my data in the correct destination buffer */
rc=ompi_datatype_copy_content_same_ddt(dtype,count,
(char *)rbuf, (char *)sbuf);
if( OMPI_SUCCESS != rc ) {
goto Error;
}
return OMPI_SUCCESS;
}
/* number of data types copies that the scratch buffer can hold */
n_dts_per_buffer=((int) MAX_TMP_BUFFER)/dt_extent;
if ( 0 == n_dts_per_buffer ) {
rc=OMPI_ERROR;
goto Error;
}
/* compute number of stripes needed to process this collective */
n_data_segments=(count+n_dts_per_buffer -1 ) / n_dts_per_buffer ;
/* get my reduction communication pattern */
memset(&my_exchange_node, 0, sizeof(netpatterns_pair_exchange_node_t));
rc = netpatterns_setup_recursive_doubling_tree_node(n_peers,
my_rank_in_group, &my_exchange_node);
if(OMPI_SUCCESS != rc){
return rc;
}
count_processed=0;
/* get a pointer to the shared-memory working buffer */
/* NOTE: starting with a rather synchronous approach */
for( stripe_number=0 ; stripe_number < n_data_segments ; stripe_number++ ) {
/* get number of elements to process in this stripe */
count_this_stripe=n_dts_per_buffer;
if( count_processed + count_this_stripe > count )
count_this_stripe=count-count_processed;
/* copy data from the input buffer into the temp buffer */
sbuf_current=(char *)sbuf+count_processed*dt_extent;
rc=ompi_datatype_copy_content_same_ddt(dtype,count_this_stripe,
scratch_bufers[send_buffer], sbuf_current);
if( OMPI_SUCCESS != rc ) {
goto Error;
}
/* copy data in from the "extra" source, if need be */
if(0 < my_exchange_node.n_extra_sources) {
if ( EXCHANGE_NODE == my_exchange_node.node_type ) {
/*
** Receive data from extra node
*/
extra_rank=my_exchange_node.rank_extra_source;
rc=MCA_PML_CALL(recv(scratch_bufers[recv_buffer],
count_this_stripe,dtype,ranks_in_comm[extra_rank],
-OMPI_COMMON_TAG_ALLREDUCE, comm,
MPI_STATUSES_IGNORE));
if( 0 > rc ) {
fprintf(stderr," first recv failed in comm_allreduce_pml \n");
fflush(stderr);
goto Error;
}
/* apply collective operation to first half of the data */
if( 0 < count_this_stripe ) {
ompi_op_reduce(op,
(void *)scratch_bufers[send_buffer],
(void *)scratch_bufers[recv_buffer],
count_this_stripe,dtype);
}
} else {
/*
** Send data to "partner" node
*/
extra_rank=my_exchange_node.rank_extra_source;
rc=MCA_PML_CALL(send(scratch_bufers[send_buffer],
count_this_stripe,dtype,ranks_in_comm[extra_rank],
-OMPI_COMMON_TAG_ALLREDUCE, MCA_PML_BASE_SEND_STANDARD,
comm));
if( 0 > rc ) {
fprintf(stderr," first send failed in comm_allreduce_pml \n");
fflush(stderr);
goto Error;
}
}
/* change pointer to scratch buffer - this was we can send data
** that we have summed w/o a memory copy, and receive data into the
** other buffer, w/o fear of over writting data that has not yet
** completed being send
*/
recv_buffer^=1;
send_buffer^=1;
}
/* loop over data exchanges */
for(exchange=0 ; exchange < my_exchange_node.n_exchanges ; exchange++) {
/* is the remote data read */
pair_rank=my_exchange_node.rank_exchanges[exchange];
/* post non-blocking receive */
rc=MCA_PML_CALL(irecv(scratch_bufers[recv_buffer],
count_this_stripe,dtype,ranks_in_comm[pair_rank],
-OMPI_COMMON_TAG_ALLREDUCE,
comm,&(requests[0])));
if( 0 > rc ) {
fprintf(stderr," irecv failed in comm_allreduce_pml at iterations %d \n",
exchange);
fflush(stderr);
goto Error;
}
/* post non-blocking send */
rc=MCA_PML_CALL(isend(scratch_bufers[send_buffer],
count_this_stripe,dtype, ranks_in_comm[pair_rank],
-OMPI_COMMON_TAG_ALLREDUCE,MCA_PML_BASE_SEND_STANDARD,
comm,&(requests[1])));
if( 0 > rc ) {
fprintf(stderr," isend failed in comm_allreduce_pml at iterations %d \n",
exchange);
fflush(stderr);
goto Error;
}
/* wait on send and receive completion */
ompi_request_wait_all(2,requests,MPI_STATUSES_IGNORE);
/* reduce the data */
if( 0 < count_this_stripe ) {
ompi_op_reduce(op,
(void *)scratch_bufers[send_buffer],
(void *)scratch_bufers[recv_buffer],
count_this_stripe,dtype);
}
/* get ready for next step */
recv_buffer^=1;
send_buffer^=1;
}
/* copy data in from the "extra" source, if need be */
if(0 < my_exchange_node.n_extra_sources) {
if ( EXTRA_NODE == my_exchange_node.node_type ) {
/*
** receive the data
** */
extra_rank=my_exchange_node.rank_extra_source;
rc=MCA_PML_CALL(recv(scratch_bufers[recv_buffer],
count_this_stripe,dtype,ranks_in_comm[extra_rank],
-OMPI_COMMON_TAG_ALLREDUCE, comm,
MPI_STATUSES_IGNORE));
if( 0 > rc ) {
fprintf(stderr," last recv failed in comm_allreduce_pml \n");
fflush(stderr);
goto Error;
}
recv_buffer^=1;
send_buffer^=1;
} else {
/* send the data to the pair-rank outside of the power of 2 set
** of ranks
*/
extra_rank=my_exchange_node.rank_extra_source;
rc=MCA_PML_CALL(send((char *)scratch_bufers[send_buffer],
count_this_stripe,dtype,ranks_in_comm[extra_rank],
-OMPI_COMMON_TAG_ALLREDUCE, MCA_PML_BASE_SEND_STANDARD,
comm));
if( 0 > rc ) {
fprintf(stderr," last send failed in comm_allreduce_pml \n");
fflush(stderr);
goto Error;
}
}
}
/* copy data from the temp buffer into the output buffer */
rbuf_current = (char *) rbuf + count_processed * dt_size;
memcpy(rbuf_current,scratch_bufers[send_buffer], count_this_stripe*dt_size);
/* update the count of elements processed */
count_processed += count_this_stripe;
}
netpatterns_cleanup_recursive_doubling_tree_node(&my_exchange_node);
/* return */
return OMPI_SUCCESS;
Error:
return rc;
}