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openmpi/ompi/mca/coll/base/coll_base_barrier.c
2015-02-26 15:52:00 -05:00

443 строки
16 KiB
C

/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2015 The University of Tennessee and The University
* of Tennessee Research Foundation. 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 (c) 2008 Sun Microsystems, Inc. All rights reserved.
* Copyright (c) 2013 Los Alamos National Security, LLC. All Rights
* reserved.
* Copyright (c) 2015 Research Organization for Information Science
* and Technology (RIST). All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "mpi.h"
#include "opal/util/bit_ops.h"
#include "ompi/constants.h"
#include "ompi/communicator/communicator.h"
#include "ompi/mca/coll/coll.h"
#include "ompi/mca/coll/base/coll_tags.h"
#include "ompi/mca/pml/pml.h"
#include "ompi/mca/coll/base/coll_base_functions.h"
#include "coll_base_topo.h"
#include "coll_base_util.h"
/**
* A quick version of the MPI_Sendreceive implemented for the barrier.
* No actual data is moved across the wire, we use 0-byte messages to
* signal a two peer synchronization.
*/
static inline int
ompi_coll_base_sendrecv_zero(int dest, int stag,
int source, int rtag,
MPI_Comm comm)
{
int err, line = 0;
ompi_request_t* reqs[2];
ompi_status_public_t statuses[2];
/* post new irecv */
err = MCA_PML_CALL(irecv( NULL, 0, MPI_BYTE, source, rtag,
comm, &reqs[0]));
if (err != MPI_SUCCESS) { line = __LINE__; goto error_handler; }
/* send data to children */
err = MCA_PML_CALL(isend( NULL, 0, MPI_BYTE, dest, stag,
MCA_PML_BASE_SEND_STANDARD, comm, &reqs[1]));
if (err != MPI_SUCCESS) { line = __LINE__; goto error_handler; }
err = ompi_request_wait_all( 2, reqs, statuses );
if( MPI_ERR_IN_STATUS == err ) {
/* As we use wait_all we will get MPI_ERR_IN_STATUS which is not an error
* code that we can propagate up the stack. Instead, look for the real
* error code from the MPI_ERROR in the status.
*/
int err_index = 0;
if( MPI_SUCCESS == statuses[0].MPI_ERROR ) {
err_index = 1;
}
err = statuses[err_index].MPI_ERROR;
OPAL_OUTPUT ((ompi_coll_base_framework.framework_output, "%s:%d: Error %d occurred in the %s"
" stage of ompi_coll_base_sendrecv_zero\n",
__FILE__, line, err, (0 == err_index ? "receive" : "send")));
return err;
}
if (err != MPI_SUCCESS) { line = __LINE__; goto error_handler; }
return (MPI_SUCCESS);
error_handler:
/* Error discovered during the posting of the irecv or isend,
* and no status is available.
*/
OPAL_OUTPUT ((ompi_coll_base_framework.framework_output, "%s:%d: Error %d occurred\n",
__FILE__, line, err));
return err;
}
/*
* Barrier is ment to be a synchronous operation, as some BTLs can mark
* a request done before its passed to the NIC and progress might not be made
* elsewhere we cannot allow a process to exit the barrier until its last
* [round of] sends are completed.
*
* It is last round of sends rather than 'last' individual send as each pair of
* peers can use different channels/devices/btls and the receiver of one of
* these sends might be forced to wait as the sender
* leaves the collective and does not make progress until the next mpi call
*
*/
/*
* Simple double ring version of barrier
*
* synchronous gurantee made by last ring of sends are synchronous
*
*/
int ompi_coll_base_barrier_intra_doublering(struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
int rank, size, err = 0, line = 0, left, right;
rank = ompi_comm_rank(comm);
size = ompi_comm_size(comm);
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"ompi_coll_base_barrier_intra_doublering rank %d", rank));
left = ((rank-1)%size);
right = ((rank+1)%size);
if (rank > 0) { /* receive message from the left */
err = MCA_PML_CALL(recv((void*)NULL, 0, MPI_BYTE, left,
MCA_COLL_BASE_TAG_BARRIER, comm,
MPI_STATUS_IGNORE));
if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl; }
}
/* Send message to the right */
err = MCA_PML_CALL(send((void*)NULL, 0, MPI_BYTE, right,
MCA_COLL_BASE_TAG_BARRIER,
MCA_PML_BASE_SEND_STANDARD, comm));
if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl; }
/* root needs to receive from the last node */
if (rank == 0) {
err = MCA_PML_CALL(recv((void*)NULL, 0, MPI_BYTE, left,
MCA_COLL_BASE_TAG_BARRIER, comm,
MPI_STATUS_IGNORE));
if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl; }
}
/* Allow nodes to exit */
if (rank > 0) { /* post Receive from left */
err = MCA_PML_CALL(recv((void*)NULL, 0, MPI_BYTE, left,
MCA_COLL_BASE_TAG_BARRIER, comm,
MPI_STATUS_IGNORE));
if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl; }
}
/* send message to the right one */
err = MCA_PML_CALL(send((void*)NULL, 0, MPI_BYTE, right,
MCA_COLL_BASE_TAG_BARRIER,
MCA_PML_BASE_SEND_SYNCHRONOUS, comm));
if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl; }
/* rank 0 post receive from the last node */
if (rank == 0) {
err = MCA_PML_CALL(recv((void*)NULL, 0, MPI_BYTE, left,
MCA_COLL_BASE_TAG_BARRIER, comm,
MPI_STATUS_IGNORE));
if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl; }
}
return MPI_SUCCESS;
err_hndl:
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"%s:%4d\tError occurred %d, rank %2d",
__FILE__, line, err, rank));
return err;
}
/*
* To make synchronous, uses sync sends and sync sendrecvs
*/
int ompi_coll_base_barrier_intra_recursivedoubling(struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
int rank, size, adjsize, err, line, mask, remote;
rank = ompi_comm_rank(comm);
size = ompi_comm_size(comm);
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,
"ompi_coll_base_barrier_intra_recursivedoubling rank %d",
rank));
/* do nearest power of 2 less than size calc */
adjsize = opal_next_poweroftwo(size);
adjsize >>= 1;
/* if size is not exact power of two, perform an extra step */
if (adjsize != size) {
if (rank >= adjsize) {
/* send message to lower ranked node */
remote = rank - adjsize;
err = ompi_coll_base_sendrecv_zero(remote, MCA_COLL_BASE_TAG_BARRIER,
remote, MCA_COLL_BASE_TAG_BARRIER,
comm);
if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl;}
} else if (rank < (size - adjsize)) {
/* receive message from high level rank */
err = MCA_PML_CALL(recv((void*)NULL, 0, MPI_BYTE, rank+adjsize,
MCA_COLL_BASE_TAG_BARRIER, comm,
MPI_STATUS_IGNORE));
if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl;}
}
}
/* exchange messages */
if ( rank < adjsize ) {
mask = 0x1;
while ( mask < adjsize ) {
remote = rank ^ mask;
mask <<= 1;
if (remote >= adjsize) continue;
/* post receive from the remote node */
err = ompi_coll_base_sendrecv_zero(remote, MCA_COLL_BASE_TAG_BARRIER,
remote, MCA_COLL_BASE_TAG_BARRIER,
comm);
if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl;}
}
}
/* non-power of 2 case */
if (adjsize != size) {
if (rank < (size - adjsize)) {
/* send enter message to higher ranked node */
remote = rank + adjsize;
err = MCA_PML_CALL(send((void*)NULL, 0, MPI_BYTE, remote,
MCA_COLL_BASE_TAG_BARRIER,
MCA_PML_BASE_SEND_SYNCHRONOUS, comm));
if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl;}
}
}
return MPI_SUCCESS;
err_hndl:
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"%s:%4d\tError occurred %d, rank %2d",
__FILE__, line, err, rank));
return err;
}
/*
* To make synchronous, uses sync sends and sync sendrecvs
*/
int ompi_coll_base_barrier_intra_bruck(struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
int rank, size, distance, to, from, err, line = 0;
rank = ompi_comm_rank(comm);
size = ompi_comm_size(comm);
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,
"ompi_coll_base_barrier_intra_bruck rank %d", rank));
/* exchange data with rank-2^k and rank+2^k */
for (distance = 1; distance < size; distance <<= 1) {
from = (rank + size - distance) % size;
to = (rank + distance) % size;
/* send message to lower ranked node */
err = ompi_coll_base_sendrecv_zero(to, MCA_COLL_BASE_TAG_BARRIER,
from, MCA_COLL_BASE_TAG_BARRIER,
comm);
if (err != MPI_SUCCESS) { line = __LINE__; goto err_hndl;}
}
return MPI_SUCCESS;
err_hndl:
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"%s:%4d\tError occurred %d, rank %2d",
__FILE__, line, err, rank));
return err;
}
/*
* To make synchronous, uses sync sends and sync sendrecvs
*/
/* special case for two processes */
int ompi_coll_base_barrier_intra_two_procs(struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
int remote, err;
remote = ompi_comm_rank(comm);
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,
"ompi_coll_base_barrier_intra_two_procs rank %d", remote));
remote = (remote + 1) & 0x1;
err = ompi_coll_base_sendrecv_zero(remote, MCA_COLL_BASE_TAG_BARRIER,
remote, MCA_COLL_BASE_TAG_BARRIER,
comm);
return (err);
}
/*
* Linear functions are copied from the BASIC coll module
* they do not segment the message and are simple implementations
* but for some small number of nodes and/or small data sizes they
* are just as fast as base/tree based segmenting operations
* and as such may be selected by the decision functions
* These are copied into this module due to the way we select modules
* in V1. i.e. in V2 we will handle this differently and so will not
* have to duplicate code.
* GEF Oct05 after asking Jeff.
*/
/* copied function (with appropriate renaming) starts here */
int ompi_coll_base_barrier_intra_basic_linear(struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
int i, err, rank, size;
rank = ompi_comm_rank(comm);
size = ompi_comm_size(comm);
/* All non-root send & receive zero-length message. */
if (rank > 0) {
err = MCA_PML_CALL(send (NULL, 0, MPI_BYTE, 0,
MCA_COLL_BASE_TAG_BARRIER,
MCA_PML_BASE_SEND_STANDARD, comm));
if (MPI_SUCCESS != err) {
return err;
}
err = MCA_PML_CALL(recv (NULL, 0, MPI_BYTE, 0,
MCA_COLL_BASE_TAG_BARRIER,
comm, MPI_STATUS_IGNORE));
if (MPI_SUCCESS != err) {
return err;
}
}
/* The root collects and broadcasts the messages. */
else {
ompi_request_t** requests;
requests = (ompi_request_t**)malloc( size * sizeof(ompi_request_t*) );
for (i = 1; i < size; ++i) {
err = MCA_PML_CALL(irecv(NULL, 0, MPI_BYTE, MPI_ANY_SOURCE,
MCA_COLL_BASE_TAG_BARRIER, comm,
&(requests[i])));
if (MPI_SUCCESS != err) {
return err;
}
}
ompi_request_wait_all( size-1, requests+1, MPI_STATUSES_IGNORE );
for (i = 1; i < size; ++i) {
err = MCA_PML_CALL(send(NULL, 0, MPI_BYTE, i,
MCA_COLL_BASE_TAG_BARRIER,
MCA_PML_BASE_SEND_STANDARD, comm));
if (MPI_SUCCESS != err) {
return err;
}
}
free( requests );
}
/* All done */
return MPI_SUCCESS;
}
/* copied function (with appropriate renaming) ends here */
/*
* Another recursive doubling type algorithm, but in this case
* we go up the tree and back down the tree.
*/
int ompi_coll_base_barrier_intra_tree(struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
int rank, size, depth, err, jump, partner;
rank = ompi_comm_rank(comm);
size = ompi_comm_size(comm);
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,
"ompi_coll_base_barrier_intra_tree %d",
rank));
/* Find the nearest power of 2 of the communicator size. */
depth = opal_next_poweroftwo_inclusive(size);
for (jump=1; jump<depth; jump<<=1) {
partner = rank ^ jump;
if (!(partner & (jump-1)) && partner < size) {
if (partner > rank) {
err = MCA_PML_CALL(recv (NULL, 0, MPI_BYTE, partner,
MCA_COLL_BASE_TAG_BARRIER, comm,
MPI_STATUS_IGNORE));
if (MPI_SUCCESS != err)
return err;
} else if (partner < rank) {
err = MCA_PML_CALL(send (NULL, 0, MPI_BYTE, partner,
MCA_COLL_BASE_TAG_BARRIER,
MCA_PML_BASE_SEND_STANDARD, comm));
if (MPI_SUCCESS != err)
return err;
}
}
}
depth >>= 1;
for (jump = depth; jump>0; jump>>=1) {
partner = rank ^ jump;
if (!(partner & (jump-1)) && partner < size) {
if (partner > rank) {
err = MCA_PML_CALL(send (NULL, 0, MPI_BYTE, partner,
MCA_COLL_BASE_TAG_BARRIER,
MCA_PML_BASE_SEND_STANDARD, comm));
if (MPI_SUCCESS != err)
return err;
} else if (partner < rank) {
err = MCA_PML_CALL(recv (NULL, 0, MPI_BYTE, partner,
MCA_COLL_BASE_TAG_BARRIER, comm,
MPI_STATUS_IGNORE));
if (MPI_SUCCESS != err)
return err;
}
}
}
return MPI_SUCCESS;
}