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
|
/*************************************************************************
* Copyright (c) 2016-2018, NVIDIA CORPORATION. All rights reserved.
*
* See LICENSE.txt for license information
************************************************************************/
#include "core.h"
#include "utils.h"
#include "transport.h"
#include "param.h"
#include "shm.h"
#include <unistd.h>
#include <cuda_runtime.h>
struct shmConnectInfo {
uint64_t pidHash;
int id;
int sendRank;
int recvRank;
int shmSize;
};
struct shmSendResources {
int remShmSize;
struct ncclRecvMem* remHostMem;
struct ncclRecvMem* devRemHostMem;
int shmSize;
struct ncclSendMem* hostMem;
struct ncclSendMem* devHostMem;
};
struct shmRecvResources {
int remShmSize;
struct ncclSendMem* remHostMem;
struct ncclSendMem* devRemHostMem;
int shmSize;
struct ncclRecvMem* hostMem;
struct ncclRecvMem* devHostMem;
};
NCCL_PARAM(ShmDisable, "SHM_DISABLE", 0);
/* Determine if we can communicate with the peer */
ncclResult_t shmCanConnect(ncclTvalue_t* ret, struct ncclPeerInfo* myInfo, struct ncclPeerInfo* peerInfo) {
*ret = ((ncclParamShmDisable() == 1) || (myInfo->hostHash != peerInfo->hostHash)) ? 0 : 1;
return ncclSuccess;
}
static inline int groupFirst(int nranks, int* groups, int group, int rankToAvoid) {
for (int rank = 0; rank<nranks; rank++) {
if ((groups[rank] == group) && (rank != rankToAvoid)) return rank;
}
return -1;
}
static inline int groupLast(int nranks, int* groups, int group, int rankToAvoid) {
for (int rank = nranks-1; rank>=0; rank--) {
if ((groups[rank] == group) && (rank != rankToAvoid)) return rank;
}
return -1;
}
ncclResult_t shmGetRings(int nranks, int* groups, int* subgroups, ncclTvalue_t* values, int* nringsRet, int* prev, int* next, int minScore, int* nthreads) {
if (*nringsRet == MAXCHANNELS) *nringsRet = 1;
int nGroups = groups[nranks-1] + 1;
int starts[nGroups];
int ends[nGroups];
for (int ring = 0; ring<*nringsRet; ring++) {
int startGroup = -1, endGroup = -1;
for (int group = 0; group<nGroups; group++) {
int start = -1;
int end = -1;
int nranksInGroup = 0;
for (int rank=0; rank<nranks; rank++) {
if (groups[rank] != group) continue;
nranksInGroup++;
if (prev[ring*nranks+rank] != -1) {
if (start != -1) {
WARN("Multiple starts found in group");
}
start = rank;
startGroup = group;
}
if (next[ring*nranks+rank] != -1) {
if (end != -1) {
WARN("Multiple ends found in group");
}
end = rank;
endGroup = group;
}
}
if (nranksInGroup == 1) {
start = end = groupFirst(nranks, groups, group, -1);
} else {
if (start == -1)
start = groupFirst(nranks, groups, group, end);
if (end == -1)
end = groupLast(nranks, groups, group, start);
}
if (start == -1 || end == -1) {
*nringsRet = ring;
return ncclSuccess;
}
starts[group] = start;
ends[group] = end;
}
if (endGroup == -1 || startGroup == -1) {
startGroup = 0;
endGroup = nGroups-1;
// Close the loop
next[ring*nranks+ends[endGroup]] = starts[startGroup];
prev[ring*nranks+starts[startGroup]] = ends[endGroup];
}
int group = startGroup;
for (int i=0; i<nGroups-2; i++) {
int nextGroup = (group+1)%nGroups;
if (nextGroup == endGroup) nextGroup = (nextGroup+1)%nGroups;
next[ring*nranks+ends[group]] = starts[nextGroup];
prev[ring*nranks+starts[nextGroup]] = ends[group];
group = nextGroup;
}
// Connect with the last
next[ring*nranks+ends[group]] = starts[endGroup];
prev[ring*nranks+starts[endGroup]] = ends[group];
}
return ncclSuccess;
}
#define MAX_SHM_NAME_LEN 1024
/* Create and return connect structures for this peer to connect to me */
ncclResult_t shmSendSetup(struct ncclPeerInfo* myInfo, struct ncclPeerInfo* peerInfo, struct ncclConnect* connectInfo, struct ncclConnector* send, int buffSize, int channelId) {
struct shmSendResources* resources;
NCCLCHECK(ncclCalloc(&resources, 1));
send->transportResources = resources;
struct shmConnectInfo info;
info.id = channelId;
info.pidHash = myInfo->pidHash;
info.sendRank = myInfo->rank;
info.recvRank = peerInfo->rank;
char shmName[MAX_SHM_NAME_LEN];
sprintf(shmName, "nccl-shm-send-%lx-%d-%d-%d", info.pidHash, info.id, info.sendRank, info.recvRank);
info.shmSize = resources->shmSize = sizeof(struct ncclSendMem);
TRACE(NCCL_SHM,"Open shmName %s shmSize %d", shmName, info.shmSize);
NCCLCHECK(shmOpen(shmName, resources->shmSize, (void**)&resources->hostMem, (void**)&resources->devHostMem, 1));
INFO(NCCL_INIT|NCCL_SHM,"Ring %02d : %d[%d] -> %d[%d] via direct shared memory", channelId, myInfo->rank, myInfo->cudaDev, peerInfo->rank, peerInfo->cudaDev);
static_assert(sizeof(struct shmConnectInfo) <= sizeof(struct ncclConnect), "shm Connect Recv Info is too big");
memcpy(connectInfo, &info, sizeof(struct shmConnectInfo));
return ncclSuccess;
}
ncclResult_t shmRecvSetup(struct ncclPeerInfo* myInfo, struct ncclPeerInfo* peerInfo, struct ncclConnect* connectInfo, struct ncclConnector* recv, int buffSize, int channelId) {
struct shmRecvResources* resources;
NCCLCHECK(ncclCalloc(&resources, 1));
recv->transportResources = resources;
struct shmConnectInfo info;
info.id = channelId;
info.pidHash = myInfo->pidHash;
info.sendRank = peerInfo->rank;
info.recvRank = myInfo->rank;
char shmName[MAX_SHM_NAME_LEN];
sprintf(shmName, "nccl-shm-recv-%lx-%d-%d-%d", info.pidHash, info.id, info.sendRank, info.recvRank);
info.shmSize = resources->shmSize = offsetof(struct ncclRecvMem, buff)+buffSize;
TRACE(NCCL_SHM,"Open shmName %s shmSize %d", shmName, info.shmSize);
NCCLCHECK(shmOpen(shmName, resources->shmSize, (void**)&resources->hostMem, (void**)&resources->devHostMem, 1));
static_assert(sizeof(struct shmConnectInfo) <= sizeof(struct ncclConnect), "shm Connect Send Info is too big");
memcpy(connectInfo, &info, sizeof(struct shmConnectInfo));
return ncclSuccess;
}
/* Connect to this peer */
ncclResult_t shmSendConnect(struct ncclConnect* connectInfo, struct ncclConnector* send) {
// Setup device pointers
struct shmConnectInfo* info = (struct shmConnectInfo*)connectInfo;
struct shmSendResources* resources = (struct shmSendResources*)send->transportResources;
char shmName[MAX_SHM_NAME_LEN];
sprintf(shmName, "nccl-shm-recv-%lx-%d-%d-%d", info->pidHash, info->id, info->sendRank, info->recvRank);
resources->remShmSize = info->shmSize;
TRACE(NCCL_SHM,"Open shmName %s shmSize %d", shmName, info->shmSize);
NCCLCHECK(shmOpen(shmName, resources->remShmSize, (void**)&resources->remHostMem, (void**)&resources->devRemHostMem, 0));
// Remove the file to ensure proper clean-up
NCCLCHECK(shmUnlink(shmName));
send->transportResources = resources;
send->conn.buff = resources->devRemHostMem->buff;
send->conn.llBuff = resources->devRemHostMem->llBuff;
send->conn.tail = &resources->devRemHostMem->tail;
send->conn.opCountRem = &resources->devRemHostMem->opCount;
send->conn.head = &resources->devHostMem->head;
send->conn.opCountLoc = &resources->devHostMem->opCount;
return ncclSuccess;
}
ncclResult_t shmRecvConnect(struct ncclConnect* connectInfo, struct ncclConnector* recv) {
// Setup device pointers
struct shmRecvResources* resources = (struct shmRecvResources*)recv->transportResources;
struct shmConnectInfo* info = (struct shmConnectInfo*)connectInfo;
char shmName[MAX_SHM_NAME_LEN];
sprintf(shmName, "nccl-shm-send-%lx-%d-%d-%d", info->pidHash, info->id, info->sendRank, info->recvRank);
resources->remShmSize = info->shmSize;
TRACE(NCCL_SHM,"Open shmName %s shmSize %d", shmName, info->shmSize);
NCCLCHECK(shmOpen(shmName, resources->remShmSize, (void**)&resources->remHostMem, (void**)&resources->devRemHostMem, 0));
NCCLCHECK(shmUnlink(shmName));
recv->conn.head = &resources->devRemHostMem->head;
recv->conn.opCountRem = &resources->devRemHostMem->opCount;
recv->conn.buff = resources->devHostMem->buff;
recv->conn.llBuff = resources->devHostMem->llBuff;
recv->conn.tail = &resources->devHostMem->tail;
recv->conn.opCountLoc = &resources->devHostMem->opCount;
return ncclSuccess;
}
ncclResult_t shmSendFree(void* transportResources) {
struct shmSendResources* resources = (struct shmSendResources*)transportResources;
NCCLCHECK(shmClose(resources->hostMem, resources->devHostMem, resources->shmSize));
NCCLCHECK(shmClose(resources->remHostMem, resources->devRemHostMem, resources->remShmSize));
free(resources);
return ncclSuccess;
}
ncclResult_t shmRecvFree(void* transportResources) {
struct shmRecvResources* resources = (struct shmRecvResources*)transportResources;
NCCLCHECK(shmClose(resources->hostMem, resources->devHostMem, resources->shmSize));
NCCLCHECK(shmClose(resources->remHostMem, resources->devRemHostMem, resources->remShmSize));
free(resources);
return ncclSuccess;
}
struct ncclTransport shmTransport = {
"SHM",
shmCanConnect,
shmGetRings,
{ shmSendSetup, shmSendConnect, shmSendFree, NULL },
{ shmRecvSetup, shmRecvConnect, shmRecvFree, NULL }
};
|
