File: scoll_basic_broadcast.c

package info (click to toggle)
openmpi 5.0.7-1
  • links: PTS, VCS
  • area: main
  • in suites: trixie
  • size: 202,312 kB
  • sloc: ansic: 612,441; makefile: 42,495; sh: 11,230; javascript: 9,244; f90: 7,052; java: 6,404; perl: 5,154; python: 1,856; lex: 740; fortran: 61; cpp: 20; tcl: 12
file content (260 lines) | stat: -rw-r--r-- 9,406 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
/*
 * Copyright (c) 2013      Mellanox Technologies, Inc.
 *                         All rights reserved.
 * Copyright (c) 2019      Research Organization for Information Science
 *                         and Technology (RIST).  All rights reserved.
 * $COPYRIGHT$
 *
 * Additional copyrights may follow
 *
 * $HEADER$
 */

#include "oshmem_config.h"
#include <stdio.h>
#include <stdlib.h>

#include "opal/util/bit_ops.h"

#include "oshmem/constants.h"
#include "oshmem/mca/spml/spml.h"
#include "oshmem/mca/scoll/scoll.h"
#include "oshmem/mca/scoll/base/base.h"
#include "scoll_basic.h"

static int _algorithm_central_counter(struct oshmem_group_t *group,
                                       int PE_root,
                                       void *target,
                                       const void *source,
                                       size_t nlong,
                                       long *pSync);
static int _algorithm_binomial_tree(struct oshmem_group_t *group,
                                     int PE_root,
                                     void *target,
                                     const void *source,
                                     size_t nlong,
                                     long *pSync);

int mca_scoll_basic_broadcast(struct oshmem_group_t *group,
                              int PE_root,
                              void *target,
                              const void *source,
                              size_t nlong,
                              long *pSync,
                              bool nlong_type,
                              int alg)
{
    int rc = OSHMEM_SUCCESS;

    /* Arguments validation */
    if (!group) {
        SCOLL_ERROR("Active set (group) of PE is not defined");
        rc = OSHMEM_ERR_BAD_PARAM;
    }

    /* Check if this PE is part of the group */
    if ((rc == OSHMEM_SUCCESS) && oshmem_proc_group_is_member(group)) {
        int i = 0;

        /* Do nothing on zero-length request */
        if (OPAL_UNLIKELY(nlong_type && !nlong)) {
            return OSHMEM_SUCCESS;
        }

        if (pSync) {
            alg = (alg == SCOLL_DEFAULT_ALG ?
                    mca_scoll_basic_param_broadcast_algorithm : alg);
            switch (alg) {
            case SCOLL_ALG_BROADCAST_CENTRAL_COUNTER:
                {
                    rc = _algorithm_central_counter(group,
                                                     PE_root,
                                                     target,
                                                     source,
                                                     nlong,
                                                     pSync);
                    break;
                }
            case SCOLL_ALG_BROADCAST_BINOMIAL:
                {
                    rc = _algorithm_binomial_tree(group,
                                                   PE_root,
                                                   target,
                                                   source,
                                                   nlong,
                                                   pSync);
                    break;
                }
            default:
                {
                    rc = _algorithm_binomial_tree(group,
                                                   PE_root,
                                                   target,
                                                   source,
                                                   nlong,
                                                   pSync);
                }
            }
        } else {
            SCOLL_ERROR("Incorrect argument pSync");
            rc = OSHMEM_ERR_BAD_PARAM;
        }

        /* Restore initial values */
        SCOLL_VERBOSE(12,
                      "[#%d] Restore special synchronization array",
                      group->my_pe);
        for (i = 0; pSync && (i < _SHMEM_BCAST_SYNC_SIZE); i++) {
            pSync[i] = _SHMEM_SYNC_VALUE;
        }
    }

    return rc;
}

/*
 This algorithm is quite simple and straightforward. But because of it�s obvious simplicity and
 the naive prove for correctness it is implemented quite often. The root send data to all.
 Outlay:
 NP-1 competing network transfers are needed to implement the counter
 The memory usage is constant (1 byte) per node.
 */
static int _algorithm_central_counter(struct oshmem_group_t *group,
                                       int PE_root,
                                       void *target,
                                       const void *source,
                                       size_t nlong,
                                       long *pSync)
{
    int rc = OSHMEM_SUCCESS;
    int i = 0;

    SCOLL_VERBOSE(12,
                  "[#%d] Broadcast algorithm: Central Counter",
                  group->my_pe);
    SCOLL_VERBOSE(15,
                  "[#%d] pSync[0] = %ld root = #%d",
                  group->my_pe, pSync[0], PE_root);

    /* Check if this PE is the root */
    if (PE_root == group->my_pe) {
        int pe_cur = 0;

        SCOLL_VERBOSE(14,
                      "[#%d] send data to all PE in the group",
                      group->my_pe);
        for (i = 0; (i < group->proc_count) && (rc == OSHMEM_SUCCESS); i++) {
            pe_cur = oshmem_proc_pe_vpid(group, i);
            if (pe_cur != PE_root) {
                SCOLL_VERBOSE(15,
                              "[#%d] send data to #%d",
                              group->my_pe, pe_cur);
                rc = MCA_SPML_CALL(put(oshmem_ctx_default, target, nlong, (void *)source, pe_cur));
            }
        }
        /* quiet is needed because scoll level barrier does not
         * guarantee put completion
         */
        MCA_SPML_CALL(quiet(oshmem_ctx_default));
    }

    if (rc == OSHMEM_SUCCESS) {
        SCOLL_VERBOSE(14, "[#%d] Wait for operation completion", group->my_pe);
        /* wait until root finishes sending data  */
        rc = BARRIER_FUNC(group,
                (pSync + 1),
                SCOLL_DEFAULT_ALG);
    }

    return rc;
}

/*
 The Binomial Spanning Tree algorithm.
 Outlay:
 The game scales with log2(NP) and uses 1 byte of memory.
 */
static int _algorithm_binomial_tree(struct oshmem_group_t *group,
                                     int PE_root,
                                     void *target,
                                     const void *source,
                                     size_t nlong,
                                     long *pSync)
{
    int rc = OSHMEM_SUCCESS;
    long value = SHMEM_SYNC_INIT;
    int root_id = oshmem_proc_group_find_id(group, PE_root);
    int my_id = oshmem_proc_group_find_id(group, group->my_pe);
    int peer_id = 0;
    int peer_pe = 0;
    int vrank;
    int dim = opal_cube_dim(group->proc_count);
    int hibit;
    int mask;
    int i = 0;

    SCOLL_VERBOSE(12, "[#%d] Broadcast algorithm: Tree", group->my_pe);
    SCOLL_VERBOSE(15,
                  "[#%d] pSync[0] = %ld root = #%d",
                  group->my_pe, pSync[0], PE_root);

    vrank = (my_id + group->proc_count - root_id) % group->proc_count;
    hibit = opal_hibit(vrank, dim);

    SCOLL_VERBOSE(15,
                  "[#%d] dim = %d vrank = %d hibit = %d",
                  group->my_pe, dim, vrank, hibit);

    dim--;

    pSync[0] = SHMEM_SYNC_READY;
    /* Receive data from parent in the tree. */
    if (vrank > 0) {
        value = SHMEM_SYNC_READY;

        SCOLL_VERBOSE(14, "[#%d] wait", group->my_pe);
        rc = MCA_SPML_CALL(wait((void*)pSync, SHMEM_CMP_NE, (void*)&value, SHMEM_LONG));
        while ((value = pSync[0]) < 0) {
            SCOLL_VERBOSE(14,
                          "[#%d] Broadcast size is a negative value (%li)\n",
                          group->my_pe, pSync[0]);
            MCA_SPML_CALL(wait((void*)pSync, SHMEM_CMP_NE, (void*)&value, SHMEM_LONG));
        }
        if (OSHMEM_SUCCESS != rc) {
            return rc;
        }
        nlong = (size_t) pSync[0];
    }

    /* Send data to the children. */
    for (i = hibit + 1, mask = 1 << i; i <= dim; ++i, mask <<= 1) {
        peer_id = vrank | mask;

        if (peer_id < group->proc_count) {
            /* Wait for the child to be ready to receive (pSync must have the initial value) */
            peer_id = (peer_id + root_id) % group->proc_count;
            peer_pe = oshmem_proc_pe_vpid(group, peer_id);

            SCOLL_VERBOSE(14,
                          "[#%d] check remote pe is ready to receive #%d",
                          group->my_pe, peer_pe);
            do {
                rc = MCA_SPML_CALL(get(oshmem_ctx_default, (void*)pSync, sizeof(long), (void*)pSync, peer_pe));
            } while ((OSHMEM_SUCCESS == rc) && (pSync[0] != SHMEM_SYNC_READY));

            SCOLL_VERBOSE(14, "[#%d] send data to #%d", group->my_pe, peer_pe);
            rc = MCA_SPML_CALL(put(oshmem_ctx_default, target, nlong, (my_id == root_id ? (void *)source : target), peer_pe));

            MCA_SPML_CALL(fence(oshmem_ctx_default));

            SCOLL_VERBOSE(14, "[#%d] signals to #%d", group->my_pe, peer_pe);
            value = nlong;
            rc = MCA_SPML_CALL(put(oshmem_ctx_default, (void*)pSync, sizeof(value), (void*)&value, peer_pe));
            if (OSHMEM_SUCCESS != rc) {
                break;
            }
        }
    }

    return rc;
}