517 строки
20 KiB
C
517 строки
20 KiB
C
/*
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* Copyright (c) 2006 The Trustees of Indiana University and Indiana
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* University Research and Technology
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* Corporation. All rights reserved.
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* Copyright (c) 2006 The Technical University of Chemnitz. All
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* rights reserved.
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*
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* Author(s): Torsten Hoefler <htor@cs.indiana.edu>
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*
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*/
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#include "nbc_internal.h"
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#include <assert.h>
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static inline int allred_sched_diss(int rank, int p, int count, MPI_Datatype datatype, void *sendbuf, void *recvbuf, MPI_Op op, NBC_Schedule *schedule, NBC_Handle *handle);
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static inline int allred_sched_chain(int rank, int p, int count, MPI_Datatype datatype, void *sendbuf, void *recvbuf, MPI_Op op, int size, int ext, NBC_Schedule *schedule, NBC_Handle *handle, int fragsize);
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static inline int allred_sched_ring(int rank, int p, int count, MPI_Datatype datatype, void *sendbuf, void *recvbuf, MPI_Op op, int size, int ext, NBC_Schedule *schedule, NBC_Handle *handle);
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#ifdef NBC_CACHE_SCHEDULE
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/* tree comparison function for schedule cache */
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int NBC_Allreduce_args_compare(NBC_Allreduce_args *a, NBC_Allreduce_args *b, void *param) {
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if( (a->sendbuf == b->sendbuf) &&
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(a->recvbuf == b->recvbuf) &&
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(a->count == b->count) &&
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(a->datatype == b->datatype) &&
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(a->op == b->op) ) {
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return 0;
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}
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if( a->sendbuf < b->sendbuf ) {
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return -1;
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}
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return +1;
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}
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#endif
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int ompi_coll_libnbc_iallreduce(void* sendbuf, void* recvbuf, int count, MPI_Datatype datatype, MPI_Op op,
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struct ompi_communicator_t *comm, ompi_request_t ** request,
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struct mca_coll_base_module_2_0_0_t *module)
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{
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int rank, p, res, size;
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MPI_Aint ext;
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NBC_Schedule *schedule;
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#ifdef NBC_CACHE_SCHEDULE
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NBC_Allreduce_args *args, *found, search;
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#endif
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enum { NBC_ARED_BINOMIAL, NBC_ARED_RING } alg;
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char inplace;
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NBC_Handle *handle;
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ompi_coll_libnbc_request_t **coll_req = (ompi_coll_libnbc_request_t**) request;
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ompi_coll_libnbc_module_t *libnbc_module = (ompi_coll_libnbc_module_t*) module;
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NBC_IN_PLACE(sendbuf, recvbuf, inplace);
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res = NBC_Init_handle(comm, coll_req, libnbc_module);
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if(res != NBC_OK) { printf("Error in NBC_Init_handle(%i)\n", res); return res; }
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res = MPI_Comm_rank(comm, &rank);
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if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Comm_rank() (%i)\n", res); return res; }
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res = MPI_Comm_size(comm, &p);
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if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Comm_size() (%i)\n", res); return res; }
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res = MPI_Type_extent(datatype, &ext);
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if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Type_extent() (%i)\n", res); return res; }
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res = MPI_Type_size(datatype, &size);
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if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Type_size() (%i)\n", res); return res; }
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handle->tmpbuf = malloc(ext*count);
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if(handle->tmpbuf == NULL) { printf("Error in malloc() (%i)\n", res); return NBC_OOR; }
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if((p == 1) && !inplace) {
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/* for a single node - copy data to receivebuf */
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res = NBC_Copy(sendbuf, count, datatype, recvbuf, count, datatype, comm);
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if (NBC_OK != res) { printf("Error in NBC_Copy() (%i)\n", res); return res; }
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}
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/* algorithm selection */
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if(p < 4 || size*count < 65536) {
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alg = NBC_ARED_BINOMIAL;
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} else {
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alg = NBC_ARED_RING;
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}
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#ifdef NBC_CACHE_SCHEDULE
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/* search schedule in communicator specific tree */
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search.sendbuf=sendbuf;
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search.recvbuf=recvbuf;
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search.count=count;
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search.datatype=datatype;
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search.op=op;
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found = (NBC_Allreduce_args*)hb_tree_search((hb_tree*)handle->comminfo->NBC_Dict[NBC_ALLREDUCE], &search);
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if(found == NULL) {
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#endif
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schedule = (NBC_Schedule*)malloc(sizeof(NBC_Schedule));
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if (NULL == schedule) { printf("Error in malloc()\n"); return res; }
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res = NBC_Sched_create(schedule);
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if(res != NBC_OK) { printf("Error in NBC_Sched_create (%i)\n", res); return res; }
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switch(alg) {
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case NBC_ARED_BINOMIAL:
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res = allred_sched_diss(rank, p, count, datatype, sendbuf, recvbuf, op, schedule, handle);
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break;
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case NBC_ARED_RING:
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res = allred_sched_ring(rank, p, count, datatype, sendbuf, recvbuf, op, size, ext, schedule, handle);
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break;
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}
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if (NBC_OK != res) { printf("Error in Schedule creation() (%i)\n", res); return res; }
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res = NBC_Sched_commit(schedule);
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if(res != NBC_OK) { free(handle->tmpbuf); printf("Error in NBC_Sched_commit() (%i)\n", res); return res; }
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#ifdef NBC_CACHE_SCHEDULE
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/* save schedule to tree */
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args = (NBC_Allreduce_args*)malloc(sizeof(NBC_Allreduce_args));
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args->sendbuf=sendbuf;
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args->recvbuf=recvbuf;
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args->count=count;
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args->datatype=datatype;
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args->op=op;
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args->schedule=schedule;
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res = hb_tree_insert ((hb_tree*)handle->comminfo->NBC_Dict[NBC_ALLREDUCE], args, args, 0);
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if(res != 0) printf("error in dict_insert() (%i)\n", res);
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/* increase number of elements for A2A */
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if(++handle->comminfo->NBC_Dict_size[NBC_ALLREDUCE] > NBC_SCHED_DICT_UPPER) {
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NBC_SchedCache_dictwipe((hb_tree*)handle->comminfo->NBC_Dict[NBC_ALLREDUCE], &handle->comminfo->NBC_Dict_size[NBC_ALLREDUCE]);
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}
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} else {
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/* found schedule */
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schedule=found->schedule;
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}
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#endif
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res = NBC_Start(handle, schedule);
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if(res != NBC_OK) { free(handle->tmpbuf); printf("Error in NBC_Start() (%i)\n", res); return res; }
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/* tmpbuf is freed with the handle */
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return NBC_OK;
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}
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/* binomial allreduce (binomial tree up and binomial bcast down)
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* working principle:
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* - each node gets a virtual rank vrank
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* - the 'root' node get vrank 0
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* - node 0 gets the vrank of the 'root'
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* - all other ranks stay identical (they do not matter)
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*
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* Algorithm:
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* pairwise exchange
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* round r:
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* grp = rank % 2^r
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* if grp == 0: receive from rank + 2^(r-1) if it exists and reduce value
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* if grp == 1: send to rank - 2^(r-1) and exit function
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*
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* do this for R=log_2(p) rounds
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* followed by a Bcast:
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* Algorithm:
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* - each node with vrank > 2^r and vrank < 2^r+1 receives from node
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* vrank - 2^r (vrank=1 receives from 0, vrank 0 receives never)
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* - each node sends each round r to node vrank + 2^r
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* - a node stops to send if 2^r > commsize
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*
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*/
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#define RANK2VRANK(rank, vrank, root) \
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{ \
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vrank = rank; \
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if (rank == 0) vrank = root; \
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if (rank == root) vrank = 0; \
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}
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#define VRANK2RANK(rank, vrank, root) \
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{ \
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rank = vrank; \
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if (vrank == 0) rank = root; \
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if (vrank == root) rank = 0; \
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}
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static inline int allred_sched_diss(int rank, int p, int count, MPI_Datatype datatype, void *sendbuf, void *recvbuf, MPI_Op op, NBC_Schedule *schedule, NBC_Handle *handle) {
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int root, vrank, r, maxr, firstred, vpeer, peer, res;
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root = 0; /* this makes the code for ireduce and iallreduce nearly identical - could be changed to improve performance */
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RANK2VRANK(rank, vrank, root);
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maxr = (int)ceil((log(p)/LOG2));
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firstred = 1;
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for(r=1; r<=maxr; r++) {
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if((vrank % (1<<r)) == 0) {
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/* we have to receive this round */
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vpeer = vrank + (1<<(r-1));
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VRANK2RANK(peer, vpeer, root)
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if(peer<p) {
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res = NBC_Sched_recv(0, true, count, datatype, peer, schedule);
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if(res != NBC_OK) { free(handle->tmpbuf); printf("Error in NBC_Sched_recv() (%i)\n", res); return res; }
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/* we have to wait until we have the data */
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res = NBC_Sched_barrier(schedule);
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if(res != NBC_OK) { free(handle->tmpbuf); printf("Error in NBC_Sched_barrier() (%i)\n", res); return res; }
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if(firstred) {
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/* perform the reduce with the senbuf */
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res = NBC_Sched_op(recvbuf, false, sendbuf, false, 0, true, count, datatype, op, schedule);
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firstred = 0;
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} else {
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/* perform the reduce in my local buffer */
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res = NBC_Sched_op(recvbuf, false, recvbuf, false, 0, true, count, datatype, op, schedule);
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}
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if(res != NBC_OK) { free(handle->tmpbuf); printf("Error in NBC_Sched_op() (%i)\n", res); return res; }
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/* this cannot be done until handle->tmpbuf is unused :-( */
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res = NBC_Sched_barrier(schedule);
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if(res != NBC_OK) { free(handle->tmpbuf); printf("Error in NBC_Sched_barrier() (%i)\n", res); return res; }
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}
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} else {
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/* we have to send this round */
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vpeer = vrank - (1<<(r-1));
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VRANK2RANK(peer, vpeer, root)
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if(firstred) {
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/* we have to use the sendbuf in the first round .. */
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res = NBC_Sched_send(sendbuf, false, count, datatype, peer, schedule);
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} else {
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/* and the recvbuf in all remeining rounds */
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res = NBC_Sched_send(recvbuf, false, count, datatype, peer, schedule);
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}
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if(res != NBC_OK) { free(handle->tmpbuf); printf("Error in NBC_Sched_send() (%i)\n", res); return res; }
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/* leave the game */
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break;
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}
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}
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/* this is the Bcast part - copied with minor changes from nbc_ibcast.c
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* changed: buffer -> recvbuf */
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RANK2VRANK(rank, vrank, root);
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/* receive from the right hosts */
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if(vrank != 0) {
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for(r=0; r<maxr; r++) {
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if((vrank >= (1<<r)) && (vrank < (1<<(r+1)))) {
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VRANK2RANK(peer, vrank-(1<<r), root);
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res = NBC_Sched_recv(recvbuf, false, count, datatype, peer, schedule);
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if(res != NBC_OK) { free(handle->tmpbuf); printf("Error in NBC_Sched_recv() (%i)\n", res); return res; }
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}
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}
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res = NBC_Sched_barrier(schedule);
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if(NBC_OK != res) { free(handle->tmpbuf); printf("Error in NBC_Sched_barrier() (%i)\n", res); return res; }
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}
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/* now send to the right hosts */
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for(r=0; r<maxr; r++) {
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if(((vrank + (1<<r) < p) && (vrank < (1<<r))) || (vrank == 0)) {
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VRANK2RANK(peer, vrank+(1<<r), root);
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res = NBC_Sched_send(recvbuf, false, count, datatype, peer, schedule);
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if(res != NBC_OK) { free(handle->tmpbuf); printf("Error in NBC_Sched_send() (%i)\n", res); return res; }
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}
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}
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/* end of the bcast */
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return NBC_OK;
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}
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static inline int allred_sched_chain(int rank, int p, int count, MPI_Datatype datatype, void *sendbuf, void *recvbuf, MPI_Op op, int size, int ext, NBC_Schedule *schedule, NBC_Handle *handle, int fragsize) {
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int res, rrpeer, rbpeer, srpeer, sbpeer, numfrag, fragnum, fragcount, thiscount, bstart, bend;
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long roffset, boffset;
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/* reduce peers */
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rrpeer = rank+1;
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srpeer = rank-1;
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/* bcast peers */
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rbpeer = rank-1;
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sbpeer = rank+1;
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if(count == 0) return NBC_OK;
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numfrag = count*size/fragsize;
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if((count*size)%fragsize != 0) numfrag++;
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fragcount = count/numfrag;
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/* determine the starting round of bcast ... the first reduced packet
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* is after p-1 rounds at rank 0 and will be sent back ... */
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bstart = p-1+rank;
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/* determine the ending round of bcast ... after arrival of the first
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* packet, each rank has to forward numfrag packets */
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bend = bstart+numfrag;
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/*printf("[%i] numfrag: %i, count: %i, size: %i, fragcount: %i, bstart: %i, bend: %i\n", rank, numfrag, count, size, fragcount, bstart, bend);*/
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/* this are two loops in one - this is a little nasty :-( */
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for(fragnum = 0; fragnum < bend; fragnum++) {
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roffset = fragnum*fragcount*ext;
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boffset = (fragnum-bstart)*fragcount*ext;
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thiscount = fragcount;
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/* first numfrag rounds ... REDUCE to rank 0 */
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if(fragnum < numfrag) {
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if(fragnum == numfrag-1) {
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/* last fragment may not be full */
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thiscount = count-fragcount*fragnum;
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}
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/*printf("[%i] reduce %i elements from %lu\n", rank, thiscount, roffset); */
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/* REDUCE - PART last node does not recv */
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if(rank != p-1) {
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res = NBC_Sched_recv((char*)roffset, true, thiscount, datatype, rrpeer, schedule);
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if (NBC_OK != res) { printf("Error in NBC_Sched_recv() (%i)\n", res); return res; }
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res = NBC_Sched_barrier(schedule);
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/* root reduces into receivebuf */
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if(rank == 0) {
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res = NBC_Sched_op((char*)recvbuf+roffset, false, (char*)sendbuf+roffset, false, (char*)roffset, true, thiscount, datatype, op, schedule);
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} else {
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res = NBC_Sched_op((char*)roffset, true, (char*)sendbuf+roffset, false, (char*)roffset, true, thiscount, datatype, op, schedule);
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}
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res = NBC_Sched_barrier(schedule);
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}
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/* REDUCE PART root does not send */
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if(rank != 0) {
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/* rank p-1 has to send out of sendbuffer :) */
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if(rank == p-1) {
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res = NBC_Sched_send((char*)sendbuf+roffset, false, thiscount, datatype, srpeer, schedule);
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} else {
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res = NBC_Sched_send((char*)roffset, true, thiscount, datatype, srpeer, schedule);
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}
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if (NBC_OK != res) { printf("Error in NBC_Sched_send() (%i)\n", res); return res; }
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/* this barrier here seems awkward but isn't!!!! */
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/*res = NBC_Sched_barrier(schedule);*/
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}
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}
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/* BCAST from rank 0 */
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if(fragnum >= bstart) {
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/*printf("[%i] bcast %i elements from %lu\n", rank, thiscount, boffset); */
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if(fragnum == bend-1) {
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/* last fragment may not be full */
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thiscount = count-fragcount*(fragnum-bstart);
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}
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/* BCAST PART root does not receive */
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if(rank != 0) {
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res = NBC_Sched_recv((char*)recvbuf+boffset, false, thiscount, datatype, rbpeer, schedule);
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if (NBC_OK != res) { printf("Error in NBC_Sched_recv() (%i)\n", res); return res; }
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res = NBC_Sched_barrier(schedule);
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}
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/* BCAST PART last rank does not send */
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if(rank != p-1) {
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res = NBC_Sched_send((char*)recvbuf+boffset, false, thiscount, datatype, sbpeer, schedule);
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if (NBC_OK != res) { printf("Error in NBC_Sched_send() (%i)\n", res); return res; }
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res = NBC_Sched_barrier(schedule);
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}
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}
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}
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/*NBC_PRINT_SCHED(*schedule);*/
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return NBC_OK;
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}
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static inline int allred_sched_ring(int r, int p, int count, MPI_Datatype datatype, void *sendbuf, void *recvbuf, MPI_Op op, int size, int ext, NBC_Schedule *schedule, NBC_Handle *handle) {
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int i; /* runner */
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int segsize, *segsizes, *segoffsets; /* segment sizes and offsets per segment (number of segments == number of nodes */
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int speer, rpeer; /* send and recvpeer */
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if(count == 0) return NBC_OK;
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{
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int mycount; /* temporary */
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segsizes = (int*)malloc(sizeof(int)*p);
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segoffsets = (int*)malloc(sizeof(int)*p);
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segsize = count/p; /* size of the segments */
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if(count%p != 0) segsize++;
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mycount = count;
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segoffsets[0] = 0;
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for(i = 0; i<p;i++) {
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mycount -= segsize;
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segsizes[i] = segsize;
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if(mycount < 0) {
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segsizes[i] = segsize+mycount;
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mycount = 0;
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}
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if(i) segoffsets[i] = segoffsets[i-1] + segsizes[i-1];
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/*if(!r) printf("count: %i, (%i) size: %i, offset: %i\n", count, i, segsizes[i], segoffsets[i]); */
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}
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}
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/* reduce peers */
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speer = (r+1)%p;
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rpeer = (r-1+p)%p;
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/* + -> reduced this round
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* / -> sum (reduced in a previous step)
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*
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* *** round 0 ***
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* 0 1 2
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*
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* 00 10 20 0: [1] -> 1
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* 01 11 21 1: [2] -> 2
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* 02 12 22 2: [0] -> 0 --> send element (r+1)%p to node (r+1)%p
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*
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* *** round 1 ***
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* 0 1 2
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*
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* 00+20 10 20 0: red(0), [0] -> 1
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* 01 11+01 21 1: red(1), [1] -> 2
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* 02 12 22+12 2: red(2), [2] -> 0 --> reduce and send element (r+0)%p to node (r+1)%p
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*
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* *** round 2 ***
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* 0 1 2
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*
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* 00/20 all 20 0: red(2), [2] -> 1
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* 01 11/01 all 1: red(0), [0] -> 2
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* all 12 22/12 2: red(1), [1] -> 0 --> reduce and send (r-1)%p to node (r+1)%p
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*
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* *** round 3 ***
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* 0 1 2
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*
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* 00/20 all all 0: [1] -> 1
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* all 11/01 all 1: [2] -> 2
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* all all 22/12 2: [0] -> 0 --> send element (r-2)%p to node (r+1)%p
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*
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* *** round 4 ***
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* 0 1 2
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*
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* all all all 0: done
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* all all all 1: done
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* all all all 2: done
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*
|
|
* -> 4
|
|
* *** round 0 ***
|
|
* 0 1 2 3
|
|
*
|
|
* 00 10 20 30 0: [1] -> 1
|
|
* 01 11 21 31 1: [2] -> 2
|
|
* 02 12 22 32 2: [3] -> 3
|
|
* 03 13 23 33 3: [0] -> 0 --> send element (r+1)%p to node (r+1)%p
|
|
*
|
|
* *** round 1 ***
|
|
* 0 1 2 3
|
|
*
|
|
* 00+30 10 20 30 0: red(0), [0] -> 1
|
|
* 01 11+01 21 31 1: red(1), [1] -> 2
|
|
* 02 12 22+12 32 2: red(2), [2] -> 3
|
|
* 03 13 23 33+23 3: red(3), [3] -> 0 --> reduce and send element (r+0)%p to node (r+1)%p
|
|
*
|
|
* *** round 2 ***
|
|
* 0 1 2 3
|
|
*
|
|
* 00/30 10+00/30 20 30 0: red(3), [3] -> 1
|
|
* 01 11/01 21+11/01 31 1: red(0), [0] -> 2
|
|
* 02 12 22/12 32+22/12 2: red(1), [1] -> 3
|
|
* 03+33/23 13 23 33/23 3: red(2), [2] -> 0 --> reduce and send (r-1)%p to node (r+1)%p
|
|
*
|
|
* *** round 3 ***
|
|
* 0 1 2 3
|
|
*
|
|
* 00/30 10/00/30 all 30 0: red(2), [2] -> 1
|
|
* 01 11/01 21/11/01 all 1: red(3), [3] -> 2
|
|
* all 12 22/12 32/22/12 2: red(0), [0] -> 3
|
|
* 03/33/23 all 23 33/23 3: red(1), [1] -> 0 --> reduce and send (r-2)%p to node (r+1)%p
|
|
*
|
|
* *** round 4 ***
|
|
* 0 1 2 3
|
|
*
|
|
* 00/30 10/00/30 all all 0: [1] -> 1
|
|
* all 11/01 21/11/01 all 1: [2] -> 2
|
|
* all all 22/12 32/22/12 2: [3] -> 3
|
|
* 03/33/23 all all 33/23 3: [0] -> 0 --> receive and send element (r+1)%p to node (r+1)%p
|
|
*
|
|
* *** round 5 ***
|
|
* 0 1 2 3
|
|
*
|
|
* all 10/00/30 all all 0: [0] -> 1
|
|
* all all 21/11/01 all 1: [1] -> 2
|
|
* all all all 32/22/12 2: [3] -> 3
|
|
* 03/33/23 all all all 3: [4] -> 4 --> receive and send element (r-0)%p to node (r+1)%p
|
|
*
|
|
* *** round 6 ***
|
|
* 0 1 2 3
|
|
*
|
|
* all all all all
|
|
* all all all all
|
|
* all all all all
|
|
* all all all all receive element (r-1)%p
|
|
*
|
|
* 2p-2 rounds ... every node does p-1 reductions and p-1 sends
|
|
*
|
|
*/
|
|
{
|
|
int round = 0;
|
|
/* first p-1 rounds are reductions */
|
|
do {
|
|
int selement = (r+1-round + 2*p /*2*p avoids negative mod*/)%p; /* the element I am sending */
|
|
int soffset = segoffsets[selement]*ext;
|
|
int relement = (r-round + 2*p /*2*p avoids negative mod*/)%p; /* the element that I receive from my neighbor */
|
|
int roffset = segoffsets[relement]*ext;
|
|
|
|
/* first message come out of sendbuf */
|
|
if(round == 0) {
|
|
NBC_Sched_send((char*)sendbuf+soffset, false, segsizes[selement], datatype, speer, schedule);
|
|
} else {
|
|
NBC_Sched_send((char*)recvbuf+soffset, false, segsizes[selement], datatype, speer, schedule);
|
|
}
|
|
NBC_Sched_recv((char*)recvbuf+roffset, false, segsizes[relement], datatype, rpeer, schedule);
|
|
|
|
NBC_Sched_barrier(schedule);
|
|
NBC_Sched_op((char*)recvbuf+roffset, false, (char*)sendbuf+roffset, false, (char*)recvbuf+roffset, false, segsizes[relement], datatype, op, schedule);
|
|
NBC_Sched_barrier(schedule);
|
|
|
|
round++;
|
|
} while(round < p-1);
|
|
|
|
do {
|
|
int selement = (r+1-round + 2*p /*2*p avoids negative mod*/)%p; /* the element I am sending */
|
|
int soffset = segoffsets[selement]*ext;
|
|
int relement = (r-round + 2*p /*2*p avoids negative mod*/)%p; /* the element that I receive from my neighbor */
|
|
int roffset = segoffsets[relement]*ext;
|
|
|
|
NBC_Sched_send((char*)recvbuf+soffset, false, segsizes[selement], datatype, speer, schedule);
|
|
NBC_Sched_recv((char*)recvbuf+roffset, false, segsizes[relement], datatype, rpeer, schedule);
|
|
NBC_Sched_barrier(schedule);
|
|
round++;
|
|
} while (round < 2*p-2);
|
|
}
|
|
|
|
return NBC_OK;
|
|
}
|