AI/rocm-systems
2
0
Förgrening 0
Kod Ärenden Pull-förfrågningar Actions Packages Projekt Släpp Wiki Aktiviteter

2.6.4-1

Bläddra i källkod 
Add support for network collectives.
Add support for XML topology dump/injection.
Add text values for GDR and P2P Levels, including "NVL".
Add speed detection for PCI, Infiniband and Ethernet cards.
Add CPU detection for ARM and AMD CPUs.
Add support for adaptive routing on Infiniband.
Change NET plugin API to v3 : merge PCI path and GPU pointer
  capability into a single structure and add other properties.
This commit is contained in:
Sylvain Jeaugey
2020-01-16 16:02:42 -08:00
förälder c38f174bd4
incheckning b221128eca
48 ändrade filer med 3621 tillägg och 1398 borttagningar
Download Patch File Download Diff File Expand all files Collapse all files
src/graph/connect.cc
+51 -2
Visa fil
@@ -1,5 +1,5 @@
/*************************************************************************
* Copyright (c) 2016-2019, NVIDIA CORPORATION. All rights reserved.
* Copyright (c) 2016-2020, NVIDIA CORPORATION. All rights reserved.
*
* See LICENSE.txt for license information
************************************************************************/
@@ -14,7 +14,7 @@
/******************************************************************/
ncclResult_t ncclTopoPreset(struct ncclComm* comm,
struct ncclTopoGraph* treeGraph, struct ncclTopoGraph* ringGraph,
struct ncclTopoGraph* treeGraph, struct ncclTopoGraph* ringGraph, struct ncclTopoGraph* collNetGraph,
struct ncclTopoRanks* topoRanks) {
int rank = comm->rank;
int localRanks = comm->localRanks;
@@ -27,9 +27,14 @@ ncclResult_t ncclTopoPreset(struct ncclComm* comm,
for (int i=0; i<NCCL_MAX_TREE_ARITY; i++) channel->treeUp.down[i] = -1;
channel->treeDn.up = -1;
for (int i=0; i<NCCL_MAX_TREE_ARITY; i++) channel->treeDn.down[i] = -1;
channel->collTreeUp.up = -1;
for (int i=0; i<NCCL_MAX_TREE_ARITY; i++) channel->collTreeUp.down[i] = -1;
channel->collTreeDn.up = -1;
for (int i=0; i<NCCL_MAX_TREE_ARITY; i++) channel->collTreeDn.down[i] = -1;
int* ringIntra = ringGraph->intra+c*localRanks;
int* treeIntra = treeGraph->intra+c*localRanks;
int* collNetIntra = collNetGraph->intra+c*localRanks;
for (int i=0; i<localRanks; i++) {
if (ringIntra[i] == rank) {
@@ -57,6 +62,16 @@ ncclResult_t ncclTopoPreset(struct ncclComm* comm,
channel->treeUp.down[0] = sym ? channel->treeDn.down[0] : channel->treeDn.up ;
channel->treeUp.up = sym ? channel->treeDn.up : channel->treeDn.down[0];
}
if (collNetIntra[i] == rank) {
int prev = (i-1+localRanks)%localRanks, next = (i+1)%localRanks;
// CollTrees are always symmetric, i.e.
// up/down go in reverse directions
channel->collTreeDn.up = collNetIntra[prev];
channel->collTreeDn.down[0] = collNetIntra[next];
channel->collTreeUp.down[0] = channel->collTreeDn.down[0];
channel->collTreeUp.up = channel->collTreeDn.up;
}
}
topoRanks->ringPrev[c] = channel->ring.prev;
topoRanks->ringNext[c] = channel->ring.next;
@@ -174,6 +189,40 @@ static ncclResult_t connectTrees(struct ncclComm* comm, int* treeUpRecv, int* tr
return ncclSuccess;
}
ncclResult_t ncclTopoConnectCollNet(struct ncclComm* comm, struct ncclTopoGraph* collNetGraph, int rank) {
int nranks = comm->nRanks;
int depth = nranks/comm->nNodes;
int sendIndex = collNetGraph->pattern == NCCL_TOPO_PATTERN_TREE ? 0 : 1; // send GPU index depends on topo pattern
int sendEndIndex = (sendIndex+comm->localRanks-1)%comm->localRanks;
for (int c=0; c<comm->nChannels/2; c++) {
struct ncclChannel* channel = comm->channels+c;
// Set root of collTree to id nranks
if (rank == collNetGraph->intra[sendIndex+c*comm->localRanks]) { // is master
channel->collTreeUp.up = channel->collTreeDn.up = nranks;
}
if (rank == collNetGraph->intra[sendEndIndex+c*comm->localRanks]) { // is bottom of intra-node chain
channel->collTreeUp.down[0] = channel->collTreeDn.down[0] = -1;
}
channel->collTreeUp.depth = channel->collTreeDn.depth = depth;
INFO(NCCL_GRAPH, "CollNet Channel %d rank %d up %d down %d", c, rank, channel->collTreeUp.up, channel->collTreeUp.down[0]);
}
int recvIndex = 0; // recv GPU index is always 0
int recvEndIndex = (recvIndex+comm->localRanks-1)%comm->localRanks;
for (int c=0; c<comm->nChannels/2; c++) {
struct ncclChannel* channel = comm->channels+comm->nChannels/2+c;
// Set root of collTree to id nranks
if (rank == collNetGraph->intra[recvIndex+c*comm->localRanks]) { // is master
channel->collTreeUp.up = channel->collTreeDn.up = nranks;
}
if (rank == collNetGraph->intra[recvEndIndex+c*comm->localRanks]) { // is bottom of intra-node chain
channel->collTreeUp.down[0] = channel->collTreeDn.down[0] = -1;
}
channel->collTreeUp.depth = channel->collTreeDn.depth = depth;
INFO(NCCL_GRAPH, "CollNet Channel %d rank %d up %d down %d", comm->nChannels/2+c, rank, channel->collTreeDn.up, channel->collTreeDn.down[0]);
}
return ncclSuccess;
}
// Legacy naming
NCCL_PARAM(MinNrings, "MIN_NRINGS", -2);
NCCL_PARAM(MaxNrings, "MAX_NRINGS", -2);
src/graph/paths.cc
+169 -116
Visa fil
@@ -1,5 +1,5 @@
/*************************************************************************
* Copyright (c) 2018-2019, NVIDIA CORPORATION. All rights reserved.
* Copyright (c) 2018-2020, NVIDIA CORPORATION. All rights reserved.
*
* See LICENSE.txt for license information
************************************************************************/
@@ -42,7 +42,7 @@ static ncclResult_t ncclTopoSetPaths(struct ncclTopoNode* baseNode, struct ncclT
NCCLCHECK(getPath(system, baseNode, baseNode->type, baseNode->id, &basePath));
basePath->count = 0;
basePath->width = LOC_WIDTH;
basePath->type = LINK_LOC;
basePath->type = PATH_LOC;
while (nodeList.count) {
nextNodeList.count = 0;
@@ -58,7 +58,7 @@ static ncclResult_t ncclTopoSetPaths(struct ncclTopoNode* baseNode, struct ncclT
}
struct ncclTopoLinkList* remPath;
NCCLCHECK(getPath(system, remNode, baseNode->type, baseNode->id, &remPath));
int width = std::min(path->width, link->width);
float width = std::min(path->width, link->width);
if (remPath->width < width) {
// Find reverse link
for (int l=0; l<remNode->nlinks; l++) {
@@ -68,8 +68,8 @@ static ncclResult_t ncclTopoSetPaths(struct ncclTopoNode* baseNode, struct ncclT
}
}
if (remPath->list[0] == NULL) {
WARN("Failed to find reverse path from remNode id %d type %d nlinks %d to node id %d type %d",
remNode->id, remNode->type, remNode->nlinks, node->id, node->type);
WARN("Failed to find reverse path from remNode %d/%lx nlinks %d to node %d/%lx",
remNode->type, remNode->id, remNode->nlinks, node->type, node->id);
return ncclInternalError;
}
// Copy the rest of the path
@@ -77,9 +77,17 @@ static ncclResult_t ncclTopoSetPaths(struct ncclTopoNode* baseNode, struct ncclT
remPath->count = path->count + 1;
remPath->width = width;
// Consider the path is QPI when going through the CPU
// Also don't consider LINK_NET as we only care about the NIC->GPU path.
int type = remNode->type == CPU ? LINK_QPI : link->type == LINK_NET ? 0 : link->type;
// Start with path type = link type. PATH and LINK types are supposed to match.
// Don't consider LINK_NET as we only care about the NIC->GPU path.
int type = link->type == LINK_NET ? 0 : link->type;
// Differentiate between one and multiple PCI switches
if (type == PATH_PIX && (node->type == PCI || link->remNode->type == PCI) && remPath->count > 3) type = PATH_PXB;
// Consider a path going through the CPU as PATH_PHB
if (link->type == LINK_PCI && (node->type == CPU || link->remNode->type == CPU)) type = PATH_PHB;
// Ignore Power CPU in an NVLink path
if (path->type == PATH_NVL && type == PATH_SYS && link->remNode->type == CPU &&
link->remNode->cpu.arch == NCCL_TOPO_CPU_ARCH_POWER) type = 0;
remPath->type = std::max(path->type, type);
// Add to the list for the next iteration if not already in the list
@@ -117,9 +125,9 @@ static void printNodePaths(struct ncclTopoSystem* system, struct ncclTopoNode* n
sprintf(line+offset, "--%s->%s/%lX", topoLinkTypeStr[link->type], topoNodeTypeStr[remNode->type], remNode->id);
offset = strlen(line);
}
INFO(NCCL_GRAPH, "%s (%d)", line, node->paths[t][n].width);
INFO(NCCL_GRAPH, "%s (%f)", line, node->paths[t][n].width);
#else
sprintf(line+offset, "%s/%lX (%d/%d/%d) ", topoNodeTypeStr[t], system->nodes[t].nodes[n].id, node->paths[t][n].count, node->paths[t][n].width, node->paths[t][n].type);
sprintf(line+offset, "%s/%lX (%d/%f/%s) ", topoNodeTypeStr[t], system->nodes[t].nodes[n].id, node->paths[t][n].count, node->paths[t][n].width, topoPathTypeStr[node->paths[t][n].type]);
offset = strlen(line);
#endif
}
@@ -171,7 +179,7 @@ static ncclResult_t addCpuStep(struct ncclTopoSystem* system, int c, int t1, int
// Update path characteristics
srcNode->paths[t2][i2].count = l;
srcNode->paths[t2][i2].type = LINK_QPI;
srcNode->paths[t2][i2].type = std::max(srcNode->paths[CPU][c].type, cpuNode->paths[t2][i2].type);
srcNode->paths[t2][i2].width = std::min(srcNode->paths[CPU][c].width, cpuNode->paths[t2][i2].width);
return ncclSuccess;
}
@@ -194,6 +202,127 @@ static void ncclTopoRemovePathType(struct ncclTopoSystem* system, int nodeType)
}
}
static const int levelsOldToNew[] = { PATH_LOC, PATH_PIX, PATH_PXB, PATH_PHB, PATH_SYS, PATH_SYS };
ncclResult_t ncclGetLevel(int* level, const char* disableEnv, const char* levelEnv) {
if (*level == -1) {
int l = -1;
if (disableEnv) {
char* str = getenv(disableEnv);
if (str) {
int disable = strtol(str, NULL, 0);
if (disable == 1) l = 0;
}
}
if (l == -1) {
char* str = getenv(levelEnv);
if (str) {
for (int i=0; i<PATH_NET; i++) {
if (strcmp(str, topoPathTypeStr[i]) == 0) {
l = i;
break;
}
}
// Old style numbering
if (l == -1 && str[0] >= '0' && str[0] <= '9') {
int oldLevel = strtol(str, NULL, 0);
const int maxOldLevel = sizeof(levelsOldToNew)/sizeof(int) - 1;
if (oldLevel > maxOldLevel) oldLevel = maxOldLevel;
l = levelsOldToNew[oldLevel];
}
}
}
if (l >= 0) INFO(NCCL_GRAPH, "%s set from environment to %s", levelEnv, topoPathTypeStr[l]);
*level = l >= 0 ? l : -2;
}
return ncclSuccess;
}
int ncclTopoUserP2pLevel = -1;
ncclResult_t ncclTopoCheckP2p(struct ncclTopoSystem* system, int64_t id1, int64_t id2, int* p2p) {
*p2p = 0;
// Get GPUs from topology
int g1, g2;
NCCLCHECK(ncclTopoIdToIndex(system, GPU, id1, &g1));
struct ncclTopoNode* gpu1 = system->nodes[GPU].nodes+g1;
if (ncclTopoIdToIndex(system, GPU, id2, &g2) == ncclInternalError) {
// GPU not found, we can't use p2p.
return ncclSuccess;
}
struct ncclTopoLinkList* path = gpu1->paths[GPU]+g2;
// In general, use P2P whenever we can.
int p2pLevel = PATH_SYS;
// Don't use P2P through ARM CPUs
int arch, vendor, model;
NCCLCHECK(ncclTopoCpuType(system, &arch, &vendor, &model));
if (arch == NCCL_TOPO_CPU_ARCH_ARM) p2pLevel = PATH_PXB;
if (arch == NCCL_TOPO_CPU_ARCH_X86 &&
vendor == NCCL_TOPO_CPU_VENDOR_INTEL &&
model == NCCL_TOPO_CPU_TYPE_BDW) p2pLevel = PATH_PXB;
// User override
NCCLCHECK(ncclGetLevel(&ncclTopoUserP2pLevel, "NCCL_P2P_DISABLE", "NCCL_P2P_LEVEL"));
if (ncclTopoUserP2pLevel != -2) p2pLevel = ncclTopoUserP2pLevel;
// Compute the PCI distance and compare with the p2pLevel.
if (path->type <= p2pLevel) *p2p = 1;
return ncclSuccess;
}
NCCL_PARAM(NetGdrRead, "NET_GDR_READ", -2);
int ncclTopoUserGdrLevel = -1;
ncclResult_t ncclTopoCheckGdr(struct ncclTopoSystem* system, int64_t busId, int netDev, int read, int* useGdr) {
*useGdr = 0;
// Get GPU and NET
int n, g;
NCCLCHECK(ncclTopoIdToIndex(system, NET, netDev, &n));
struct ncclTopoNode* net = system->nodes[NET].nodes+n;
NCCLCHECK(ncclTopoIdToIndex(system, GPU, busId, &g));
struct ncclTopoNode* gpu = system->nodes[GPU].nodes+g;
// Check that both the NIC and GPUs support it
if (net->net.gdrSupport == 0) return ncclSuccess;
if (gpu->gpu.gdrSupport == 0) return ncclSuccess;
if (read) { // For reads (sends) only enable under certain conditions
int gdrReadParam = ncclParamNetGdrRead();
if (gdrReadParam == 0) return ncclSuccess;
if (gdrReadParam < 0) {
int nvlink = 0;
// Since we don't know whether there are other communicators,
// it's better to keep things local if we have a single GPU.
if (system->nodes[GPU].count == 1) nvlink = 1;
for (int i=0; i<system->nodes[GPU].count; i++) {
if (i == g) continue;
if (gpu->paths[GPU][i].type == PATH_NVL) {
nvlink = 1;
break;
}
}
if (!nvlink) return ncclSuccess;
}
}
// Check if we are close enough that it makes sense to enable GDR
int netGdrLevel = PATH_PXB;
NCCLCHECK(ncclGetLevel(&ncclTopoUserGdrLevel, NULL, "NCCL_NET_GDR_LEVEL"));
if (ncclTopoUserGdrLevel != -2) netGdrLevel = ncclTopoUserGdrLevel;
int distance = gpu->paths[NET][n].type;
if (distance > netGdrLevel) {
INFO(NCCL_NET,"GPU Direct RDMA Disabled for GPU %lx / HCA %d (distance %d > %d)", busId, netDev, distance, netGdrLevel);
return ncclSuccess;
}
*useGdr = 1;
INFO(NCCL_NET,"GPU Direct RDMA Enabled for GPU %lx / HCA %d (distance %d <= %d), read %d", busId, netDev, distance, netGdrLevel, read);
return ncclSuccess;
}
ncclResult_t ncclTopoComputePaths(struct ncclTopoSystem* system, struct ncclPeerInfo* peerInfos) {
// Precompute paths between GPUs/NICs.
@@ -210,26 +339,29 @@ ncclResult_t ncclTopoComputePaths(struct ncclTopoSystem* system, struct ncclPeer
// Compute paths to GPU g
NCCLCHECK(ncclTopoSetPaths(system->nodes[GPU].nodes+g, system));
// Update path when we don't want to / can't use GPU Direct P2P
for (int p=0; p<system->nodes[GPU].count; p++) {
int p2p;
NCCLCHECK(ncclTopoCheckP2p(system, system->nodes[GPU].nodes[p].id, system->nodes[GPU].nodes[g].id, &p2p));
if (p2p == 0) {
// Divert all traffic through the CPU
int cpu;
NCCLCHECK(getLocalCpu(system, g, &cpu));
NCCLCHECK(addCpuStep(system, cpu, GPU, p, GPU, g));
}
}
if (peerInfos == NULL) continue;
// Update paths from GPUs p to GPU g when we can't or don't want to use P2P or even SHM
struct ncclPeerInfo* dstInfo = peerInfos+system->nodes[GPU].nodes[g].rank;
// Remove GPUs we can't talk to because of containers.
struct ncclPeerInfo* dstInfo = peerInfos+system->nodes[GPU].nodes[g].gpu.rank;
for (int p=0; p<system->nodes[GPU].count; p++) {
if (p == g) continue;
struct ncclPeerInfo* srcInfo = peerInfos+system->nodes[GPU].nodes[p].rank;
int p2p;
NCCLCHECK(ncclTransports[TRANSPORT_P2P].canConnect(&p2p, system, NULL, srcInfo, dstInfo));
if (p2p == 0) {
int shm;
NCCLCHECK(ncclTransports[TRANSPORT_SHM].canConnect(&shm, system, NULL, srcInfo, dstInfo));
if (shm == 1) {
// We cannot use GPU Direct, so we need all traffic to go through a CPU
int cpu;
NCCLCHECK(getLocalCpu(system, g, &cpu));
NCCLCHECK(addCpuStep(system, cpu, GPU, p, GPU, g));
} else {
// We cannot communicate with that peer.
system->nodes[GPU].nodes[p].paths[GPU][g].count = 0;
}
struct ncclPeerInfo* srcInfo = peerInfos+system->nodes[GPU].nodes[p].gpu.rank;
int shm;
NCCLCHECK(ncclTransports[TRANSPORT_SHM].canConnect(&shm, system, NULL, srcInfo, dstInfo));
if (shm == 0) {
// Mark this peer as inaccessible. We'll trim it later.
system->nodes[GPU].nodes[p].paths[GPU][g].count = 0;
}
}
}
@@ -239,11 +371,12 @@ ncclResult_t ncclTopoComputePaths(struct ncclTopoSystem* system, struct ncclPeer
struct ncclTopoNode* netNode = system->nodes[NET].nodes+n;
NCCLCHECK(ncclTopoSetPaths(netNode, system));
if (peerInfos == NULL) continue;
for (int g=0; g<system->nodes[GPU].count; g++) {
if ((peerInfos[system->nodes[GPU].nodes[g].rank].gdrSupport & (1 << n)) == 0) {
// We cannot use GPU Direct RDMA, so we need all NIC<->GPU paths
// to go through a CPU
// Update path when we dont want to / can't use GPU Direct RDMA.
int gdr;
NCCLCHECK(ncclTopoCheckGdr(system, system->nodes[GPU].nodes[g].id, netNode->id, 0, &gdr));
if (gdr == 0) {
// We cannot use GPU Direct RDMA, divert all traffic through the CPU local to the GPU
int localCpu;
NCCLCHECK(getLocalCpu(system, g, &localCpu));
NCCLCHECK(addCpuStep(system, localCpu, NET, n, GPU, g));
@@ -251,7 +384,6 @@ ncclResult_t ncclTopoComputePaths(struct ncclTopoSystem* system, struct ncclPeer
}
}
}
return ncclSuccess;
}
@@ -270,7 +402,7 @@ ncclResult_t ncclTopoTrimSystem(struct ncclTopoSystem* system, struct ncclComm*
domains[g] = std::min(domains[g], domains[p]);
}
}
if (gpu->rank == comm->rank) myDomain = domains[g];
if (gpu->gpu.rank == comm->rank) myDomain = domains[g];
}
int ngpus = system->nodes[GPU].count;
@@ -288,98 +420,19 @@ ncclResult_t ncclTopoTrimSystem(struct ncclTopoSystem* system, struct ncclComm*
free(ids);
return ncclInternalError;
}
// Remove GPUs I can't access (even indirectly) from my view of the node
for (int t=0; t<NCCL_TOPO_NODE_TYPES; t++) {
for (int n=0; n<system->nodes[t].count; n++) {
struct ncclTopoNode* node = system->nodes[t].nodes+n;
if (node == gpu) continue;
for (int l=0; l<node->nlinks; l++) {
while (l<node->nlinks && node->links[l].remNode == gpu) {
if (l<node->nlinks-1)
memmove(node->links+l, node->links+l+1, (node->nlinks-l-1)*sizeof(struct ncclTopoLink));
node->nlinks--;
}
if (l<node->nlinks && node->links[l].remNode->type == GPU && node->links[l].remNode >= gpu) {
node->links[l].remNode--;
}
}
}
}
if (g != system->nodes[GPU].count-1)
memmove(gpu, gpu+1, (system->nodes[GPU].count-g-1)*sizeof(struct ncclTopoNode));
system->nodes[GPU].count--;
NCCLCHECK(ncclTopoRemoveNode(system, GPU, g));
}
comm->localRanks = system->nodes[GPU].count;
if (system->nodes[GPU].count == comm->nRanks) {
// Trim network
ncclTopoRemovePathType(system, NET);
system->nodes[NET].count = 0;
for (int t=0; t<NCCL_TOPO_NODE_TYPES; t++) {
for (int n=0; n<system->nodes[t].count; n++) {
struct ncclTopoNode* node = system->nodes[t].nodes+n;
for (int l=0; l<node->nlinks; l++) {
struct ncclTopoLink* link = &(node->links[l]);
if (link->remNode->type == NET) {
// Remove the link
for (int i=l; i<(node->nlinks-1); i++) {
memcpy(&(node->links[i]), &(node->links[i+1]), sizeof(ncclTopoLink));
}
node->nlinks--;
l--; // revisit the same value of "l" for the next iteration, since we edited the list in the middle of the loop
}
}
}
}
for (int n=system->nodes[NET].count-1; n>=0; n--)
NCCLCHECK(ncclTopoRemoveNode(system, NET, n));
}
free(domains);
free(ids);
return ncclSuccess;
}
static ncclResult_t getGpuSpeed(struct ncclTopoNode* node, int* speed) {
int nvlSpeed = 0;
int nvlPeers = 0;
int pciSpeed = 0;
for (int l=0; l<node->nlinks; l++) {
if (node->links[l].type == LINK_NVL) nvlSpeed += node->links[l].width;
if (node->links[l].remNode->type == GPU) nvlPeers++; else nvlPeers = 2;
if (node->links[l].type == LINK_PCI) pciSpeed = node->links[l].width;
}
*speed = std::min(*speed, std::max(nvlSpeed, pciSpeed));
return ncclSuccess;
}
ncclResult_t ncclTopoGetMaxSpeed(struct ncclTopoSystem* system) {
// Compute max speed to try to accelerate the search.
system->maxSpeed = LOC_WIDTH;
for (int g=0; g<system->nodes[GPU].count; g++) {
NCCLCHECK(getGpuSpeed(system->nodes[GPU].nodes+g, &system->maxSpeed));
}
if (system->nodes[NET].count) {
// Try to assign one NIC per GPU
int netMaxSpeed = 0;
int netMaxSpeedCount = 0;
for (int n=0; n<system->nodes[NET].count; n++) {
int maxSpeed = 0;
struct ncclTopoNode* net = system->nodes[NET].nodes+n;
for (int g=0; g<system->nodes[GPU].count; g++) {
maxSpeed = std::max(maxSpeed, net->paths[GPU][g].width);
}
if (maxSpeed > netMaxSpeed) {
netMaxSpeed = maxSpeed;
netMaxSpeedCount = 1;
} else if (maxSpeed == netMaxSpeed) {
netMaxSpeedCount++;
}
}
system->maxSpeed = std::min(system->maxSpeed, netMaxSpeedCount*NET_WIDTH);
}
return ncclSuccess;
}
void ncclTopoFree(struct ncclTopoSystem* system) {
for (int t=0; t<NCCL_TOPO_NODE_TYPES; t++) ncclTopoRemovePathType(system, t);
free(system);
src/graph/search.cc
+442 -226
Visa fil
@@ -1,5 +1,5 @@
/*************************************************************************
* Copyright (c) 2016-2019, NVIDIA CORPORATION. All rights reserved.
* Copyright (c) 2016-2020, NVIDIA CORPORATION. All rights reserved.
*
* See LICENSE.txt for license information
************************************************************************/
@@ -7,29 +7,121 @@
#include "core.h"
#include "graph.h"
#include "topo.h"
#include "xml.h"
#include <math.h>
static ncclResult_t ncclTopoFollowPath(struct ncclTopoGraph* graph, struct ncclTopoLinkList* path, struct ncclTopoNode** node, int width, int typeSave) {
if (path->count == 0) return ncclSuccess;
*node = NULL;
if (width > 0) {
if (path->type > graph->type) return ncclSuccess;
graph->type = std::max(graph->type, path->type);
graph->nHops += path->count;
} else {
graph->type = typeSave;
graph->nHops -= path->count;
// Initialize system->maxWidth. This is the per-channel (i.e. per-SM)
// max speed.
static float getMaxWidth(struct ncclTopoSystem* system, struct ncclTopoNode* gpu, int type) {
float nvLinkWidth = gpu->gpu.cudaCompCap > 60 ? VOLTA_NVLINK_WIDTH : PASCAL_NVLINK_WIDTH;
float maxWidth = 0.0;
for (int i=0; i<system->nodes[type].count; i++) {
struct ncclTopoLinkList* path = gpu->paths[type]+i;
float width = path->width;
if (path->count == 0) continue;
if (path->type == PATH_NVL) width = std::min(nvLinkWidth, width);
maxWidth = std::max(maxWidth, width);
}
return maxWidth;
}
ncclResult_t ncclTopoSearchInit(struct ncclTopoSystem* system) {
system->maxWidth = 0.0;
int inter = system->nodes[NET].count;
if (inter == 0 && system->nodes[GPU].count == 1) {
system->maxWidth = LOC_WIDTH;
return ncclSuccess;
}
for (int g=0; g<system->nodes[GPU].count; g++) {
struct ncclTopoNode* gpu = system->nodes[GPU].nodes+g;
system->maxWidth = std::max(system->maxWidth, getMaxWidth(system, gpu, inter ? NET : GPU));
}
return ncclSuccess;
}
for (int i=0; i<path->count; i++) {
if (path->list[i]->width < width) {
// Can't follow this path, rewind and exit
for (int j=0; j<i; j++) path->list[j]->width += width;
static ncclResult_t findRevLink(struct ncclTopoNode* node1, struct ncclTopoNode* node2, struct ncclTopoLink** revLink) {
for (int l=0; l<node2->nlinks; l++) {
struct ncclTopoLink* link = node2->links+l;
if (link->remNode == node1) {
*revLink = link;
return ncclSuccess;
}
path->list[i]->width -= width;
}
*node = path->list[path->count-1]->remNode;
WARN("Could not find rev link for %d/%d -> %d/%d\n", node1->type, node1->id, node2->type, node2->id);
return ncclInternalError;
}
// This is unfortunately needed since manipulating floats often results in rounding errors.
#define SUB_ROUND(a, b) (a = roundf((a-b)*1000)/1000)
static ncclResult_t followPath(struct ncclTopoLinkList* path, struct ncclTopoNode* start, int maxSteps, float speed, int* steps) {
float pciSpeed = speed;
for (int step=0; step<path->count; step++) {
struct ncclTopoNode* node = path->list[step]->remNode;
if (node->type == CPU) {
// Account for P2P inefficiency through Intel CPU RC
if (path->type == PATH_PHB && start->type == GPU &&
node->cpu.arch == NCCL_TOPO_CPU_ARCH_X86 &&
node->cpu.vendor == NCCL_TOPO_CPU_VENDOR_INTEL) {
pciSpeed = INTEL_P2P_OVERHEAD(speed);
}
}
}
struct ncclTopoNode* node = start;
for (int step=0; step<maxSteps; step++) {
struct ncclTopoLink* link = path->list[step];
struct ncclTopoLink* revLink = NULL;
float fwSpeed = link->type == LINK_PCI ? pciSpeed : speed;
float revSpeed = 0;
if (link->remNode->type == GPU && start->type != GPU) {
if (revLink == NULL) NCCLCHECK(findRevLink(node, link->remNode, &revLink));
revSpeed += fwSpeed/8;
}
if (link->remNode->type == CPU && link->type == LINK_NVL) {
if (revLink == NULL) NCCLCHECK(findRevLink(node, link->remNode, &revLink));
revSpeed += fwSpeed;
}
if (link->width < fwSpeed || (revSpeed && revLink->width < revSpeed)) { *steps = step; return ncclSuccess; }
SUB_ROUND(link->width, fwSpeed);
if (revSpeed) SUB_ROUND(revLink->width, revSpeed);
node = link->remNode;
}
*steps = maxSteps;
return ncclSuccess;
}
// Try to go from node type1/index1 to no type2/index2. mult indicates whether we are counting the bandwidth (1) or undoing (-1).
static ncclResult_t ncclTopoFollowPath(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, int type1, int index1, int type2, int index2, int mult, struct ncclTopoNode** node) {
// First handle easy cases
*node = system->nodes[type2].nodes+index2;
if (type1 == -1) return ncclSuccess;
struct ncclTopoNode* node1 = system->nodes[type1].nodes+index1;
struct ncclTopoLinkList* path = node1->paths[type2]+index2;
if (path->count == 0 ) return ncclSuccess;
// Now check link type
*node = NULL;
int intra = type1 == GPU && type2 == GPU;
float speed = intra ? graph->speedIntra : graph->speedInter;
int type = intra ? graph->typeIntra : graph->typeInter;
if (mult == 1 && (path->type > type)) return ncclSuccess;
speed *= mult;
// Check there is enough bandwidth on paths.
int step = 0;
NCCLCHECK(followPath(path, node1, path->count, speed, &step));
if (step < path->count) goto rewind;
// Enough bandwidth : return destination node.
graph->nHops += mult*path->count;
*node = system->nodes[type2].nodes+index2;
return ncclSuccess;
rewind:
// Not enough bandwidth : rewind and exit.
NCCLCHECK(followPath(path, node1, step, -speed, &step));
return ncclSuccess;
}
@@ -80,22 +172,42 @@ static int cmpIntraScores(struct ncclGpuScore* scores, int count) {
return 0;
}
static ncclResult_t getNetPaths(struct ncclTopoSystem* system, const uint64_t flag, struct ncclTopoLinkList** netPaths) {
for (int n=0; n<system->nodes[NET].count; n++) {
if (system->nodes[NET].nodes[n].used & flag) {
*netPaths=system->nodes[NET].nodes[n].paths[GPU];
static ncclResult_t getGpuIndex(struct ncclTopoSystem* system, int rank, int* index) {
for (int g=0; g<system->nodes[GPU].count; g++) {
if (system->nodes[GPU].nodes[g].gpu.rank == rank) {
*index = g;
return ncclSuccess;
}
}
WARN("Could not find gpu rank %d\n", rank);
return ncclInternalError;
}
static ncclResult_t getNetIndex(struct ncclTopoSystem* system, int64_t id, int* index) {
for (int n=0; n<system->nodes[NET].count; n++) {
if (system->nodes[NET].nodes[n].id == id) {
*index = n;
return ncclSuccess;
}
}
WARN("Could not find net id %lx\n", id);
return ncclInternalError;
}
static ncclResult_t getNetPaths(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoLinkList** netPaths) {
int netId = graph->inter[graph->nChannels*2];
int n;
NCCLCHECK(getNetIndex(system, netId, &n));
*netPaths=system->nodes[NET].nodes[n].paths[GPU];
return ncclSuccess;
}
ncclResult_t ncclTopoSearchNextGpuSort(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoNode* gpu, int* next, int* countPtr, int sortNet) {
const uint64_t flag = 1ULL<<(graph->nChannels);
int ngpus = system->nodes[GPU].count;
struct ncclTopoLinkList* paths = gpu->paths[GPU];
struct ncclTopoLinkList* netPaths = NULL;
if (sortNet) NCCLCHECK(getNetPaths(system, flag, &netPaths));
if (sortNet) NCCLCHECK(getNetPaths(system, graph, &netPaths));
struct ncclGpuScore scores[NCCL_TOPO_MAX_NODES];
memset(scores, 0, ngpus*sizeof(struct ncclGpuScore));
@@ -130,9 +242,13 @@ ncclResult_t ncclTopoSearchNextGpuSort(struct ncclTopoSystem* system, struct ncc
return ncclSuccess;
}
ncclResult_t ncclTopoSearchRec(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, int maxSpeed, int* time);
ncclResult_t ncclTopoSearchRec(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, int* time);
#define NCCL_SEARCH_TIMEOUT (1ULL<<20) // This should get contain all search within a second or so.
// Try to keep all searchs within one second
#define NCCL_SEARCH_GLOBAL_TIMEOUT (3ULL<<19)
#define NCCL_SEARCH_TIMEOUT (1<<18)
#define NCCL_SEARCH_TIMEOUT_TREE (1<<17)
#define NCCL_SEARCH_TIMEOUT_SAMECHANNELS (1<<10)
#define FORCED_ORDER_PCI 1
#define FORCED_ORDER_REPLAY 2
@@ -142,7 +258,7 @@ ncclResult_t ncclTopoReplayGetGpu(struct ncclTopoSystem* system, struct ncclTopo
if (graph->nChannels == 0) return ncclInternalError;
int ngpus = system->nodes[GPU].count;
int nextRank = graph->intra[(graph->nChannels-1)*ngpus+step+1];
for (int i=0; i<ngpus; i++) if (system->nodes[GPU].nodes[i].rank == nextRank) {
for (int i=0; i<ngpus; i++) if (system->nodes[GPU].nodes[i].gpu.rank == nextRank) {
*g = i;
return ncclSuccess;
}
@@ -150,44 +266,37 @@ ncclResult_t ncclTopoReplayGetGpu(struct ncclTopoSystem* system, struct ncclTopo
return ncclSuccess;
}
ncclResult_t ncclTopoSearchRecGpu(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, struct ncclTopoNode* gpu, int step, int backToNet, int backToFirstRank, int forcedOrder, int maxSpeed, int *time);
ncclResult_t ncclTopoSearchRecGpu(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, struct ncclTopoNode* gpu, int step, int backToNet, int backToFirstRank, int forcedOrder, int *time);
ncclResult_t ncclTopoSearchTryGpu(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, struct ncclTopoLinkList* paths, int step, int backToNet, int backToFirstRank, int forcedOrder, int maxSpeed, int *time, int g, int speed) {
int typeSave = graph->type;
ncclResult_t ncclTopoSearchTryGpu(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, int step, int backToNet, int backToFirstRank, int forcedOrder, int *time, int type, int index, int g) {
const uint64_t flag = 1ULL<<(graph->nChannels);
struct ncclTopoNode* gpu = system->nodes[GPU].nodes+g;
if (paths) NCCLCHECK(ncclTopoFollowPath(graph, paths+g, &gpu, speed, typeSave));
struct ncclTopoNode* gpu;
NCCLCHECK(ncclTopoFollowPath(system, graph, type, index, GPU, g, 1, &gpu));
if (gpu) {
gpu->used ^= flag;
NCCLCHECK(ncclTopoSearchRecGpu(system, graph, saveGraph, gpu, step, backToNet, backToFirstRank, forcedOrder, maxSpeed, time));
NCCLCHECK(ncclTopoSearchRecGpu(system, graph, saveGraph, gpu, step, backToNet, backToFirstRank, forcedOrder, time));
gpu->used ^= flag;
if (paths) NCCLCHECK(ncclTopoFollowPath(graph, paths+g, &gpu, -speed, typeSave));
NCCLCHECK(ncclTopoFollowPath(system, graph, type, index, GPU, g, -1, &gpu));
}
return ncclSuccess;
}
ncclResult_t ncclTopoCompareGraphs(struct ncclTopoGraph* graph, struct ncclTopoGraph* refGraph, int* copy) {
// 0. When we are trying to increase speedIntra, do not copy if the solution has less channels
// since it would likely impact the rings algorithms too.
if (graph->speedIntra > graph->speedInter && graph->nChannels < refGraph->nChannels) return ncclSuccess;
// 1. Constraint to get the same nChannels between Rings and Trees
if (graph->nChannels < graph->minChannels) return ncclSuccess;
// 1. Try to get better bandwidth
// 2. Try to get better bandwidth
if (graph->nChannels*graph->speedIntra < refGraph->nChannels*refGraph->speedIntra) return ncclSuccess;
if (graph->nChannels*graph->speedIntra > refGraph->nChannels*refGraph->speedIntra) {
*copy = 1;
return ncclSuccess;
}
// 2. Give an advantage when all channels are the same
if (graph->nChannels > 1 && graph->sameChannels && refGraph->sameChannels == 0) {
*copy = 1;
return ncclSuccess;
}
// 3. Less hops
if (graph->nHops < refGraph->nHops) *copy = 1;
// 3. Less hops (but not at the price of going cross NICs)
if (graph->crossNic == refGraph->crossNic && graph->nHops < refGraph->nHops) *copy = 1;
return ncclSuccess;
}
ncclResult_t ncclTopoSearchRecGpu(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, struct ncclTopoNode* gpu, int step, int backToNet, int backToFirstRank, int forcedOrder, int maxSpeed, int *time) {
ncclResult_t ncclTopoSearchRecGpu(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, struct ncclTopoNode* gpu, int step, int backToNet, int backToFirstRank, int forcedOrder, int *time) {
if ((*time) <= 0) return ncclSuccess;
(*time)--;
@@ -195,51 +304,39 @@ ncclResult_t ncclTopoSearchRecGpu(struct ncclTopoSystem* system, struct ncclTopo
if (step == ngpus) {
// Determine whether we found a better solution or not
int copy = 0;
int sameChannels = graph->sameChannels;
if (graph->nChannels > 0) {
int* intra = graph->intra+graph->nChannels*ngpus;
for (int g=0; g<ngpus; g++) if (intra[g] != intra[g-ngpus]) graph->sameChannels = 0;
}
graph->nChannels++;
NCCLCHECK(ncclTopoCompareGraphs(graph, saveGraph, &copy));
if (copy) {
memcpy(saveGraph, graph, sizeof(struct ncclTopoGraph));
if (graph->nChannels*graph->speedIntra == maxSpeed) *time = -1;
if (graph->nChannels == graph->maxChannels) *time = -1;
}
if (graph->nChannels < MAXCHANNELS/2) {
NCCLCHECK(ncclTopoSearchRec(system, graph, saveGraph, maxSpeed, time));
if (graph->nChannels < graph->maxChannels) {
NCCLCHECK(ncclTopoSearchRec(system, graph, saveGraph, time));
}
graph->nChannels--;
graph->sameChannels = sameChannels;
return ncclSuccess;
}
graph->intra[graph->nChannels*ngpus+step] = gpu->rank;
graph->intra[graph->nChannels*ngpus+step] = gpu->gpu.rank;
int g = gpu - system->nodes[GPU].nodes;
if (step == backToNet) {
// first get back to NIC
if (system->nodes[NET].count) {
int maxWidth = 0;
struct ncclTopoLinkList* paths = gpu->paths[NET];
int startNetIndex;
NCCLCHECK(getNetIndex(system, graph->inter[graph->nChannels*2], &startNetIndex));
struct ncclTopoNode* startNet = system->nodes[NET].nodes+startNetIndex;
for (int n=0; n<system->nodes[NET].count; n++) {
if (graph->crossNic != 1 && (system->nodes[NET].nodes[n].id != graph->inter[graph->nChannels*2])) continue;
maxWidth = std::max(paths[n].width, maxWidth);
}
for (int n=0; n<system->nodes[NET].count; n++) {
if (graph->crossNic != 1 && (system->nodes[NET].nodes[n].id != graph->inter[graph->nChannels*2])) continue;
if (paths[n].width == maxWidth) {
struct ncclTopoNode* net = system->nodes[NET].nodes+n;
int typeSave = graph->type;
NCCLCHECK(ncclTopoFollowPath(graph, paths+n, &net, graph->speedInter, typeSave));
if (net) {
graph->inter[graph->nChannels*2+1] = net->id;
NCCLCHECK(ncclTopoSearchRecGpu(system, graph, saveGraph, gpu, step, -1, backToFirstRank, forcedOrder, maxSpeed, time));
NCCLCHECK(ncclTopoFollowPath(graph, paths+n, &net, -graph->speedInter, typeSave));
}
struct ncclTopoNode* net = system->nodes[NET].nodes+n;
if (graph->crossNic != 1 && (net->net.asic != startNet->net.asic || net->net.port != startNet->net.port)) continue;
NCCLCHECK(ncclTopoFollowPath(system, graph, GPU, g, NET, n, 1, &net));
if (net) {
graph->inter[graph->nChannels*2+1] = net->id;
NCCLCHECK(ncclTopoSearchRecGpu(system, graph, saveGraph, gpu, step, -1, backToFirstRank, forcedOrder, time));
NCCLCHECK(ncclTopoFollowPath(system, graph, GPU, g, NET, n, -1, &net));
}
}
}
} else if (step < system->nodes[GPU].count-1) {
// Go to next GPU
struct ncclTopoLinkList* paths = gpu->paths[GPU];
int next[NCCL_TOPO_MAX_NODES];
int count;
if (forcedOrder == FORCED_ORDER_PCI) { // Try the PCI order
@@ -252,64 +349,59 @@ ncclResult_t ncclTopoSearchRecGpu(struct ncclTopoSystem* system, struct ncclTopo
NCCLCHECK(ncclTopoSearchNextGpuSort(system, graph, gpu, next, &count, backToNet == -1 ? 0 : backToNet == step+1 ? 1 : -1 ));
}
for (int i=0; i<count; i++) {
int g = next[i];
int nvlink = graph->nvlink;
graph->nvlink &= paths[g].type <= LINK_NVL ? 1 : 0;
int speed = graph->speedIntra;
if (paths[g].type == LINK_QPI) speed = INTEL_P2P_OVERHEAD(speed);
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, paths, step+1, backToNet, backToFirstRank, forcedOrder, maxSpeed, time, g, speed));
graph->nvlink = nvlink;
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, step+1, backToNet, backToFirstRank, forcedOrder, time, GPU, g, next[i]));
}
} else if (step == backToFirstRank) {
// Find first GPU and loop back to it
int g;
int rank = graph->intra[graph->nChannels*ngpus];
for (g=0; g<ngpus; g++) {
if (system->nodes[GPU].nodes[g].rank == rank) break;
}
if (g == ngpus) {
WARN("Could not find GPU with rank %d\n", rank);
return ncclInternalError;
}
struct ncclTopoLinkList* paths = gpu->paths[GPU];
struct ncclTopoNode* firstGpu = system->nodes[GPU].nodes+g;
int typeSave = graph->type;
NCCLCHECK(ncclTopoFollowPath(graph, paths+g, &firstGpu, graph->speedIntra, typeSave));
int p;
NCCLCHECK(getGpuIndex(system, graph->intra[graph->nChannels*ngpus], &p));
struct ncclTopoNode* firstGpu;
NCCLCHECK(ncclTopoFollowPath(system, graph, GPU, g, GPU, p, 1, &firstGpu));
if (firstGpu) {
NCCLCHECK(ncclTopoSearchRecGpu(system, graph, saveGraph, firstGpu, step+1, backToNet, -1, forcedOrder, maxSpeed, time));
NCCLCHECK(ncclTopoFollowPath(graph, paths+g, &firstGpu, -graph->speedIntra, typeSave));
NCCLCHECK(ncclTopoSearchRecGpu(system, graph, saveGraph, firstGpu, step+1, backToNet, -1, forcedOrder, time));
NCCLCHECK(ncclTopoFollowPath(system, graph, GPU, g, GPU, p, -1, &firstGpu));
}
} else {
// Next path
NCCLCHECK(ncclTopoSearchRecGpu(system, graph, saveGraph, gpu, ngpus, -1, -1, forcedOrder, maxSpeed, time));
NCCLCHECK(ncclTopoSearchRecGpu(system, graph, saveGraph, gpu, ngpus, -1, -1, forcedOrder, time));
}
return ncclSuccess;
}
ncclResult_t ncclTopoSearchRecNet(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, int backToNet, int backToFirstRank, int maxSpeed, int* time) {
const uint64_t flag = 1ULL<<(graph->nChannels);
ncclResult_t ncclTopoSearchRecNet(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, int backToNet, int backToFirstRank, int* time) {
const int speed = graph->speedInter;
for (int n=0; n<system->nodes[NET].count; n++) {
struct ncclTopoNode* net = system->nodes[NET].nodes+n;
struct ncclTopoNode* gpu;
if (net->used == 0) {
graph->inter[graph->nChannels*2] = net->id;
for (int i=0; i<system->nodes[NET].count; i++) {
if (system->nodes[NET].nodes[i].rank == net->rank) system->nodes[NET].nodes[i].used ^= flag;
}
struct ncclTopoLinkList* paths = net->paths[GPU];
if (graph->collNet && net->net.collSupport == 0) continue;
if (net->net.width < speed) continue;
if (net->net.maxChannels == 0) continue;
// First try the PCI order to set a reference
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, paths, 0, backToNet, backToFirstRank, FORCED_ORDER_PCI, maxSpeed, time, 0, speed));
// Then try to replay the last channel
if (graph->nChannels > 0) {
int g;
NCCLCHECK(ncclTopoReplayGetGpu(system, graph, -1, &g));
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, paths, 0, backToNet, backToFirstRank, FORCED_ORDER_REPLAY, maxSpeed, time, g, speed));
graph->inter[graph->nChannels*2] = net->id;
for (int i=0; i<system->nodes[NET].count; i++) {
if ((system->nodes[NET].nodes[i].net.asic == net->net.asic) &&
(system->nodes[NET].nodes[i].net.port == net->net.port)) {
system->nodes[NET].nodes[i].net.width -= speed;
}
}
net->net.maxChannels--;
// First try to replay the last channel
if (graph->nChannels > 0) {
int g;
NCCLCHECK(ncclTopoReplayGetGpu(system, graph, -1, &g));
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, 0, backToNet, backToFirstRank, FORCED_ORDER_REPLAY, time, NET, n, g));
}
if (graph->nChannels == 0 || graph->sameChannels == 0) {
if (graph->nChannels == 0) {
// Always try the PCI order first to set a reference
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, 0, backToNet, backToFirstRank, FORCED_ORDER_PCI, time, NET, n, 0));
}
// Then try the most local GPUs
int maxWidth = 0, minHops = 0xfffffff;
float maxWidth = 0;
int minHops = 0xfffffff;
struct ncclTopoLinkList* paths = net->paths[GPU];
for (int g=0; g<system->nodes[GPU].count; g++) {
if (paths[g].width > maxWidth) {
maxWidth = paths[g].width;
@@ -328,14 +420,19 @@ ncclResult_t ncclTopoSearchRecNet(struct ncclTopoSystem* system, struct ncclTopo
gpu = system->nodes[GPU].nodes+g;
int gpuUsed = gpuPciWidth(gpu) > 0 ? 0 : 1;
if (tryGpuBidir == gpuUsed) {
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, paths, 0, backToNet, backToFirstRank, 0, maxSpeed, time, g, speed));
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, 0, backToNet, backToFirstRank, 0, time, NET, n, g));
}
}
}
}
}
for (int i=0; i<system->nodes[NET].count; i++) {
if (system->nodes[NET].nodes[i].rank == net->rank) system->nodes[NET].nodes[i].used ^= flag;
}
net->net.maxChannels++;
for (int i=0; i<system->nodes[NET].count; i++) {
if ((system->nodes[NET].nodes[i].net.asic == net->net.asic) &&
(system->nodes[NET].nodes[i].net.port == net->net.port)) {
system->nodes[NET].nodes[i].net.width += speed;
}
}
}
@@ -374,126 +471,201 @@ ncclResult_t ncclTopoSearchParams(struct ncclTopoSystem* system, int pattern, in
return ncclSuccess;
}
ncclResult_t ncclTopoSearchRec(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, int maxSpeed, int* time) {
ncclResult_t ncclTopoSearchRec(struct ncclTopoSystem* system, struct ncclTopoGraph* graph, struct ncclTopoGraph* saveGraph, int* time) {
int backToNet, backToFirstRank;
NCCLCHECK(ncclTopoSearchParams(system, graph->pattern, &backToNet, &backToFirstRank));
if (system->nodes[NET].count) {
// Start from NET
ncclTopoSearchRecNet(system, graph, saveGraph, backToNet, backToFirstRank, maxSpeed, time);
ncclTopoSearchRecNet(system, graph, saveGraph, backToNet, backToFirstRank, time);
} else {
// Start from GPU 0
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, NULL, 0, backToNet, backToFirstRank, FORCED_ORDER_PCI, maxSpeed, time, 0, graph->speedIntra));
if (graph->nChannels > 0) NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, NULL, 0, backToNet, backToFirstRank, FORCED_ORDER_REPLAY, maxSpeed, time, 0, graph->speedIntra));
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, NULL, 0, backToNet, backToFirstRank, 0, maxSpeed, time, 0, graph->speedIntra));
// Intra-node only.
if (graph->nChannels == 0) {
// Try PCI order first
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, 0, backToNet, backToFirstRank, FORCED_ORDER_PCI, time, -1, -1, 0));
} else {
// Also try to replay previous channel
int g;
NCCLCHECK(ncclTopoReplayGetGpu(system, graph, -1, &g));
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, 0, backToNet, backToFirstRank, FORCED_ORDER_REPLAY, time, -1, -1, g));
}
if (graph->sameChannels == 0 || graph->nChannels == 0) {
// Finally, try all other possibilities unless we are forced to use the same channels
for (int g=0; g<system->nodes[GPU].count; g++) {
NCCLCHECK(ncclTopoSearchTryGpu(system, graph, saveGraph, 0, backToNet, backToFirstRank, 0, time, -1, -1, g));
}
}
}
return ncclSuccess;
}
/* Parse user defined rings. Format is like :
* "0 1|1 0|0 1 2 3|3 2 1 0|0 2 3 1|1 3 2 0|0 1 2 3 4 5 6 7|7 6 5 4 3 2 1 0"
* Rings with a non-matching number of ranks are ignored so we can provide
* rings for multiple cases.
*/
#define MAX_ENV_RANKS 512
static ncclResult_t parseGraph(const char* str, int* nChannelsRet, int ngpus, int* channels) {
int ranks[MAX_ENV_RANKS];
int nChannels = 0;
int rank = 0;
int offset = 0;
int status = 0; // 0 : between numbers, 1 : inside number
do {
int digit = str[offset] - '0';
if (digit >= 0 && digit <= 9) {
if (status == 0) {
ranks[rank] = digit;
status = 1;
} else {
ranks[rank] = ranks[rank]*10+digit;
}
} else {
if (status == 1) {
rank++;
if (rank == MAX_ENV_RANKS) goto end;
}
status = 0;
if (str[offset] == '|' || str[offset] == '\0') {
// Ignore if ngpus doesn't match
if (rank != ngpus) goto newchannel;
/************************************/
/* User defined graph from XML file */
/************************************/
for (int r=0; r<ngpus; r++) {
int rank = ranks[r];
// Ignore if ranks are out of bounds
if (rank < 0 || rank >= ngpus) goto newchannel;
// Ignore if ranks are duplicate
for (int i=0; i<r; i++)
if (ranks[i] == rank) goto newchannel;
channels[nChannels*ngpus+r] = rank;
}
nChannels++;
newchannel:
rank = 0;
struct kvDict kvDictLinkType[] = { { "SYS", PATH_SYS }, { "PHB", PATH_PHB }, { "PIX", PATH_PIX }, { "PXB", PATH_PXB }, { "NVL", PATH_NVL }, { "LOC", PATH_LOC }, { NULL, 0 } };
ncclResult_t ncclTopoGetChannelFromXml(struct ncclXmlNode *xmlChannel, int c, struct ncclTopoSystem* system, struct ncclTopoGraph* graph) {
int ngpus = system->nodes[GPU].count;
int* inter = graph->inter+2*c;
int* intra = graph->intra+ngpus*c;
int n=0, g=0;
for (int s=0; s<xmlChannel->nSubs; s++) {
struct ncclXmlNode* sub = xmlChannel->subs[s];
int dev;
NCCLCHECK(xmlGetAttrInt(sub, "dev", &dev));
if (strcmp(sub->name, "net") == 0) {
inter[n++] = dev;
} else if (strcmp(sub->name, "gpu") == 0) {
int rank = -1;
for (int g=0; g<ngpus; g++) {
if (system->nodes[GPU].nodes[g].gpu.dev == dev) rank = system->nodes[GPU].nodes[g].gpu.rank;
}
if (rank == -1) {
WARN("XML Import Channel : dev %d not found.", dev);
return ncclSystemError;
}
intra[g++] = rank;
}
} while (str[offset++] != 0);
end:
*nChannelsRet = nChannels;
}
return ncclSuccess;
}
ncclResult_t ncclTopoGetGraphFromXmlSub(struct ncclXmlNode *xmlGraph, struct ncclTopoSystem* system, struct ncclTopoGraph* graph) {
int id;
NCCLCHECK(xmlGetAttrInt(xmlGraph, "id", &id));
if (graph->id != id) return ncclSuccess;
int crossNic;
NCCLCHECK(xmlGetAttrInt(xmlGraph, "crossnic", &crossNic));
if (graph->crossNic == 0 && crossNic == 1) return ncclSuccess;
graph->crossNic = crossNic;
NCCLCHECK(xmlGetAttrInt(xmlGraph, "pattern", &graph->pattern));
NCCLCHECK(xmlGetAttrInt(xmlGraph, "nchannels", &graph->nChannels));
NCCLCHECK(xmlGetAttrFloat(xmlGraph, "speedintra", &graph->speedIntra));
NCCLCHECK(xmlGetAttrFloat(xmlGraph, "speedinter", &graph->speedInter));
const char* str;
NCCLCHECK(xmlGetAttr(xmlGraph, "typeintra", &str));
NCCLCHECK(kvConvertToInt(str, &graph->typeIntra, kvDictLinkType));
NCCLCHECK(xmlGetAttr(xmlGraph, "typeinter", &str));
NCCLCHECK(kvConvertToInt(str, &graph->typeInter, kvDictLinkType));
NCCLCHECK(xmlGetAttrInt(xmlGraph, "samechannels", &graph->sameChannels));
for (int s=0; s<xmlGraph->nSubs; s++) {
NCCLCHECK(ncclTopoGetChannelFromXml(xmlGraph->subs[s], s, system, graph));
}
return ncclSuccess;
}
ncclResult_t ncclTopoGetGraphFromXml(struct ncclXmlNode *xmlGraphs, struct ncclTopoSystem* system, struct ncclTopoGraph* graph) {
for (int s=0; s<xmlGraphs->nSubs; s++) {
NCCLCHECK(ncclTopoGetGraphFromXmlSub(xmlGraphs->subs[s], system, graph));
}
return ncclSuccess;
}
/* And the reverse : graph->xml */
ncclResult_t ncclTopoGetXmlFromChannel(struct ncclTopoGraph* graph, int c, struct ncclTopoSystem* system, struct ncclXml *xml, struct ncclXmlNode* parent) {
struct ncclXmlNode* xmlChannel;
int ngpus = system->nodes[GPU].count;
int* inter = graph->inter+2*c;
int* intra = graph->intra+ngpus*c;
NCCLCHECK(xmlAddNode(xml, parent, "channel", &xmlChannel));
struct ncclXmlNode* node;
if (system->nodes[NET].count) {
NCCLCHECK(xmlAddNode(xml, xmlChannel, "net", &node));
NCCLCHECK(xmlSetAttrInt(node, "dev", inter[0]));
}
for (int g=0; g<ngpus; g++) {
NCCLCHECK(xmlAddNode(xml, xmlChannel, "gpu", &node));
int dev = -1;
for (int i=0; i<ngpus; i++) {
if (system->nodes[GPU].nodes[i].gpu.rank == intra[g]) dev = system->nodes[GPU].nodes[i].gpu.dev;
}
if (dev == -1) {
WARN("XML Export Channel : rank %d not found.", intra[g]);
return ncclInternalError;
}
NCCLCHECK(xmlSetAttrInt(node, "dev", dev));
}
if (system->nodes[NET].count) {
NCCLCHECK(xmlAddNode(xml, xmlChannel, "net", &node));
NCCLCHECK(xmlSetAttrInt(node, "dev", inter[1]));
}
return ncclSuccess;
}
ncclResult_t ncclTopoGetXmlFromGraph(struct ncclTopoGraph* graph, struct ncclTopoSystem* system, struct ncclXml *xml, struct ncclXmlNode* parent) {
struct ncclXmlNode* xmlGraph;
NCCLCHECK(xmlAddNode(xml, parent, "graph", &xmlGraph));
NCCLCHECK(xmlSetAttrInt(xmlGraph, "id", graph->id));
NCCLCHECK(xmlSetAttrInt(xmlGraph, "pattern", graph->pattern));
NCCLCHECK(xmlSetAttrInt(xmlGraph, "crossnic", graph->crossNic));
NCCLCHECK(xmlSetAttrInt(xmlGraph, "nchannels", graph->nChannels));
NCCLCHECK(xmlSetAttrFloat(xmlGraph, "speedintra", graph->speedIntra));
NCCLCHECK(xmlSetAttrFloat(xmlGraph, "speedinter", graph->speedInter));
const char* str;
NCCLCHECK(kvConvertToStr(graph->typeIntra, &str, kvDictLinkType));
NCCLCHECK(xmlSetAttr(xmlGraph, "typeintra", str));
NCCLCHECK(kvConvertToStr(graph->typeInter, &str, kvDictLinkType));
NCCLCHECK(xmlSetAttr(xmlGraph, "typeinter", str));
NCCLCHECK(xmlSetAttrInt(xmlGraph, "samechannels", graph->sameChannels));
for (int c=0; c<graph->nChannels; c++) {
NCCLCHECK(ncclTopoGetXmlFromChannel(graph, c, system, xml, xmlGraph));
}
return ncclSuccess;
}
ncclResult_t ncclTopoGetXmlFromGraphs(int ngraphs, struct ncclTopoGraph** graphs, struct ncclTopoSystem* system, struct ncclXml *xml) {
xml->maxIndex = 0;
struct ncclXmlNode* xmlGraphs;
NCCLCHECK(xmlAddNode(xml, NULL, "graphs", &xmlGraphs));
NCCLCHECK(xmlSetAttrInt(xmlGraphs, "version", NCCL_GRAPH_XML_VERSION));
for (int g=0; g<ngraphs; g++) {
NCCLCHECK(ncclTopoGetXmlFromGraph(graphs[g], system, xml, xmlGraphs));
}
return ncclSuccess;
}
float speedArray[] = { 24.0, 21.0, 18.0, 15.0, 12.0, 10.0, 9.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.4, 1.2, 0.24, 0.12 };
#define NSPEEDS (sizeof(speedArray)/sizeof(float))
ncclResult_t ncclTopoCompute(ncclTopoSystem* system, struct ncclTopoGraph* graph) {
int ngpus = system->nodes[GPU].count;
int crossNic = (system->nodes[NET].count > 1) && graph->crossNic ? 1 : 0;
graph->speedIntra = graph->speedInter = 0;
if (graph->crossNic == 2) graph->crossNic = 0;
graph->nvlink = 0;
graph->type = LINK_LOC;
graph->typeIntra = ngpus == 1 ? PATH_LOC : PATH_NVL;
graph->typeInter = PATH_PIX;
graph->nChannels = 0;
graph->sameChannels = 1;
char* str = getenv("NCCL_GRAPH");
char* str = getenv("NCCL_GRAPH_FILE");
if (str) {
NCCLCHECK(parseGraph(str, &graph->nChannels, ngpus, graph->intra));
for (int i=0; i<graph->nChannels*ngpus; i++) {
// Translate gpu numbers into ranks
graph->intra[i] = system->nodes[GPU].nodes[graph->intra[i]].rank;
}
// TODO : let user specify NICs
graph->inter[0] = graph->inter[1] = 0;
graph->speedIntra = graph->speedInter = PCI_WIDTH+2;
graph->nvlink = 0;
if (graph->pattern == NCCL_TOPO_PATTERN_RING) {
// Reverse the loop
for (int c=0; c<graph->nChannels; c++) {
for (int i=0; i<=ngpus/2; i++) {
int tmp = graph->intra[ngpus*c+i];
graph->intra[ngpus*c+i] = graph->intra[ngpus*c+(ngpus-i)%ngpus];
graph->intra[ngpus*c+ngpus-i] = tmp;
}
}
}
if (graph->nChannels) return ncclSuccess;
struct ncclXml* xml;
NCCLCHECK(ncclCalloc(&xml, 1));
NCCLCHECK(ncclTopoGetXmlGraphFromFile(str, xml));
NCCLCHECK(ncclTopoGetGraphFromXml(xml->nodes, system, graph));
free(xml);
if (graph->nChannels > 0) return ncclSuccess;
}
if (ngpus == 1) if (graph->pattern != NCCL_TOPO_PATTERN_RING) graph->pattern = NCCL_TOPO_PATTERN_TREE;
struct ncclTopoGraph tmpGraph;
memcpy(&tmpGraph, graph, sizeof(struct ncclTopoGraph));
int bestSpeed = 0;
// First try crossnic, then decrease speed and finally increase speedIntra.
tmpGraph.speedIntra = tmpGraph.speedInter = system->maxWidth;
int maxSpeed = system->maxSpeed;
tmpGraph.pattern = graph->pattern;
int pass = 1;
int speedIndex = 0;
while (speedArray[speedIndex] > system->maxWidth && speedIndex < NSPEEDS-1) speedIndex++;
tmpGraph.speedIntra = tmpGraph.speedInter = speedArray[speedIndex];
int64_t globalTimeout = NCCL_SEARCH_GLOBAL_TIMEOUT;
search:
int time = NCCL_SEARCH_TIMEOUT;
tmpGraph.nvlink = 1;
int time = tmpGraph.sameChannels ? NCCL_SEARCH_TIMEOUT_SAMECHANNELS :
tmpGraph.pattern == NCCL_TOPO_PATTERN_TREE ? NCCL_SEARCH_TIMEOUT_TREE : NCCL_SEARCH_TIMEOUT;
tmpGraph.nChannels = 0;
tmpGraph.sameChannels = 1;
NCCLCHECK(ncclTopoSearchRec(system, &tmpGraph, graph, maxSpeed, &time));
globalTimeout -= time;
NCCLCHECK(ncclTopoSearchRec(system, &tmpGraph, graph, &time));
#if 0
printf("Pattern %d, crossNic %d, Speed %d/%d, type %d -> nChannels %dx%d/%d %s\n", tmpGraph.pattern, tmpGraph.crossNic, tmpGraph.speedInter, tmpGraph.speedIntra, tmpGraph.type, graph->nChannels, graph->speedInter, graph->speedIntra, time == 0 ? "TIMEOUT" : "");
printf("Pattern %d, crossNic %d, Speed %g/%g, type %d/%d, channels %d-%d sameChannels %d -> nChannels %dx%g/%g %s\n", tmpGraph.pattern, tmpGraph.crossNic, tmpGraph.speedInter, tmpGraph.speedIntra, tmpGraph.typeInter, tmpGraph.typeIntra, tmpGraph.minChannels, tmpGraph.maxChannels, tmpGraph.sameChannels, graph->nChannels, graph->speedInter, graph->speedIntra, time == 0 ? "TIMEOUT" : "");
for (int c=0; c<graph->nChannels; c++) {
printf("%2d : ", c);
for (int g=0; g<ngpus; g++) {
@@ -502,13 +674,34 @@ search:
printf("\n");
}
#endif
if (time == -1) goto done;
// We already have a solution and we timed out so lower speed will just timeout as well
if (time == 0 && graph->nChannels > 0) goto done;
if ((graph->nChannels > 0) && (bestSpeed == 0)) bestSpeed = graph->speedIntra;
// Optimal solution, stop here
if (graph->nChannels == graph->maxChannels && graph->speedInter == system->maxWidth) goto done;
if (tmpGraph.speedIntra == tmpGraph.speedInter) {
// First pass, we don't have a solution yet ; try to go slower.
if (pass == 1) {
// First pass, we don't have a solution yet ; try other options
// Try having different channels
if (tmpGraph.sameChannels == 1) {
tmpGraph.sameChannels = 0;
goto search;
}
tmpGraph.sameChannels = 1;
if (time != -1) globalTimeout += time;
else globalTimeout = NCCL_SEARCH_GLOBAL_TIMEOUT;
if (globalTimeout < 0) goto done;
int maxTypeIntra = system->nodes[NET].count > 0 ? tmpGraph.typeInter : PATH_SYS;
if (tmpGraph.typeIntra < maxTypeIntra && (graph->nChannels == 0 || tmpGraph.typeIntra < graph->typeIntra)) {
tmpGraph.typeIntra += 1;
goto search;
}
tmpGraph.typeIntra = ngpus == 1 ? PATH_LOC : PATH_NVL;
if (system->nodes[NET].count > 0 && tmpGraph.typeInter < PATH_SYS && (graph->nChannels == 0 || tmpGraph.typeInter < graph->typeInter || tmpGraph.typeInter < PATH_PXB)) {
tmpGraph.typeInter += 1;
goto search;
}
tmpGraph.typeInter = PATH_PIX;
// Try a simpler tree
if (tmpGraph.pattern == NCCL_TOPO_PATTERN_SPLIT_TREE_LOOP) {
@@ -521,50 +714,61 @@ search:
}
tmpGraph.pattern = graph->pattern;
if (tmpGraph.type < LINK_QPI) {
tmpGraph.type += 1;
goto search;
}
tmpGraph.type = graph->type;
if (crossNic && tmpGraph.crossNic == 0) {
// Try again with crossNic if permitted
tmpGraph.crossNic = crossNic;
goto search;
}
tmpGraph.crossNic = graph->crossNic;
tmpGraph.crossNic = 0;
// Decrease speed until we find a solution
if ((speedIndex < NSPEEDS-1) && (graph->nChannels == 0 || (speedArray[speedIndex+1]/graph->speedInter > .49))) {
tmpGraph.speedInter = tmpGraph.speedIntra = speedArray[++speedIndex];
goto search;
}
speedIndex = 0;
while (speedArray[speedIndex] > system->maxWidth && speedIndex < NSPEEDS-1) speedIndex++;
tmpGraph.speedIntra = tmpGraph.speedInter = speedArray[speedIndex];
// Try to reduce speed per channel
tmpGraph.speedIntra = tmpGraph.speedInter -= 3;
if (tmpGraph.speedIntra >= bestSpeed/2 && tmpGraph.speedIntra >= 3) goto search;
}
done:
// We have a solution now. See if we can increase speedIntra
if (tmpGraph.speedIntra == tmpGraph.speedInter) {
// We have a solution. Start from that solution and move to pass 2.
if (pass == 1) {
time = -1;
memcpy(&tmpGraph, graph, sizeof(tmpGraph));
speedIndex = 0;
while (speedArray[speedIndex] > graph->speedInter && speedIndex < NSPEEDS-1) speedIndex++;
tmpGraph.speedIntra = tmpGraph.speedInter = speedArray[speedIndex];
tmpGraph.minChannels = graph->nChannels;
pass = 2;
}
// 3. See if we can increase speedIntra for trees (2 nodes or collnet)
if (pass == 2) {
if (time != 0 && graph->pattern != NCCL_TOPO_PATTERN_RING &&
tmpGraph.speedIntra == graph->speedIntra && tmpGraph.speedIntra < tmpGraph.speedInter*2 &&
speedIndex > 0) {
tmpGraph.speedIntra = speedArray[--speedIndex];
goto search;
}
time = -1;
memcpy(&tmpGraph, graph, sizeof(tmpGraph));
}
if (time != 0 && tmpGraph.pattern != NCCL_TOPO_PATTERN_RING && tmpGraph.speedIntra == graph->speedIntra) {
// Try to increase the intra speed only but keeping nChannels the same
tmpGraph.speedIntra += 3;
maxSpeed = tmpGraph.speedIntra * graph->nChannels;
if (tmpGraph.speedIntra <= tmpGraph.speedInter*2) goto search;
}
if (graph->nChannels == 0) {
if (graph->nChannels == 0 && graph->collNet == 0) {
WARN("Could not find a path for pattern %d, falling back to simple order\n", graph->pattern);
for (int i=0; i<ngpus; i++) graph->intra[i] = system->nodes[GPU].nodes[i].rank;
for (int i=0; i<ngpus; i++) graph->intra[i] = system->nodes[GPU].nodes[i].gpu.rank;
graph->inter[0] = graph->inter[1] = 0;
graph->speedIntra = graph->speedInter = 3;
graph->nvlink = 0;
graph->speedIntra = graph->speedInter = 0.1;
graph->typeIntra = graph->typeInter = PATH_SYS;
graph->nChannels = 1;
}
return ncclSuccess;
}
ncclResult_t ncclTopoPrintGraph(struct ncclTopoSystem* system, struct ncclTopoGraph* graph) {
INFO(NCCL_GRAPH, "Pattern %d, crossNic %d, nChannels %d, speed %d/%d, nvlink %d, type %d, sameChannels %d", graph->pattern, graph->crossNic, graph->nChannels, graph->speedIntra, graph->speedInter, graph->nvlink, graph->type, graph->sameChannels);
INFO(NCCL_GRAPH, "Pattern %d, crossNic %d, nChannels %d, speed %f/%f, type %s/%s, sameChannels %d", graph->pattern, graph->crossNic, graph->nChannels, graph->speedIntra, graph->speedInter, topoPathTypeStr[graph->typeIntra], topoPathTypeStr[graph->typeInter], graph->sameChannels);
int ngpus = system->nodes[GPU].count;
char line[1024];
@@ -588,6 +792,18 @@ ncclResult_t ncclTopoPrintGraph(struct ncclTopoSystem* system, struct ncclTopoGr
return ncclSuccess;
}
ncclResult_t ncclTopoDumpGraphs(struct ncclTopoSystem* system, int ngraphs, struct ncclTopoGraph** graphs) {
char* str = getenv("NCCL_GRAPH_DUMP_FILE");
if (str) {
struct ncclXml* xml;
NCCLCHECK(ncclCalloc(&xml, 1));
NCCLCHECK(ncclTopoGetXmlFromGraphs(ngraphs, graphs, system, xml));
NCCLCHECK(ncclTopoDumpXmlToFile(str, xml));
free(xml);
}
return ncclSuccess;
}
ncclResult_t ncclTopoGetNetDev(struct ncclTopoGraph* graph, int dir, int channelId, int* dev) {
*dev = graph->inter[(channelId%graph->nChannels)*2+dir];
return ncclSuccess;
src/graph/topo.cc
+487 -480
Visa fil
Filskillnaden har hållits tillbaka eftersom den är för stor Load Diff
src/graph/topo.h
+74 -68
Visa fil
@@ -1,5 +1,5 @@
/*************************************************************************
* Copyright (c) 2016-2019, NVIDIA CORPORATION. All rights reserved.
* Copyright (c) 2016-2020, NVIDIA CORPORATION. All rights reserved.
*
* See LICENSE.txt for license information
************************************************************************/
@@ -9,22 +9,24 @@
#include "graph.h"
#include "core.h"
#include <sched.h>
#define LOC_WIDTH 5000
#define PASCAL_NVLINK_WIDTH 18
#define VOLTA_NVLINK_WIDTH 21
#define PCI_WIDTH 12 // PCI Gen3 x16
#define QPI_WIDTH 8
#define SKL_QPI_WIDTH 12
#define P9_WIDTH 32
#define NET_WIDTH 12 // 100Gbit
#define LOC_WIDTH 5000.0
#define PASCAL_NVLINK_WIDTH 18.0
#define VOLTA_NVLINK_WIDTH 21.0
#define PCI_WIDTH 12.0 // PCI Gen3 x16
#define QPI_WIDTH 6.0
#define SKL_QPI_WIDTH 9.0
#define P9_WIDTH 32.0
#define ARM_WIDTH 6.0
#define NET_WIDTH 12.0 // 100Gbit
// Intel CPU convert GPU P2P traffic into 64B PCI TLPs, to GPU
// to GPU traffic consumed more PCI bandwidth.
// Intel CPU convert GPU P2P traffic into 64B PCI TLPs, so GPU
// to GPU traffic consumes more PCI bandwidth.
#define INTEL_P2P(speed) (speed*9/12)
#define INTEL_P2P_OVERHEAD(speed) (speed*12/9)
#define NCCL_TOPO_NODE_TYPES 6
#define NCCL_TOPO_NODE_TYPES 7
#define GPU 0
#define PCI 1
#define NVS 2
@@ -33,37 +35,72 @@
#define NET 5
extern const char* topoNodeTypeStr[];
// We want link types and path types to match as much as possible
#define LINK_LOC 0
#define LINK_NVL 1
#define LINK_PCI 2
#define LINK_QPI 3
#define LINK_NET 4
// Skipping 3 for PATH_PXB
// Skipping 4 for PATH_PHB
#define LINK_SYS 5
#define LINK_NET 6
extern const char* topoLinkTypeStr[];
#define PATH_LOC 0
#define PATH_NVL 1
#define PATH_PIX 2
#define PATH_PXB 3
#define PATH_PHB 4
#define PATH_SYS 5
#define PATH_NET 6
extern const char* topoPathTypeStr[];
struct ncclTopoNode;
struct ncclTopoLink {
int type;
int width;
float width;
struct ncclTopoNode* remNode;
};
#define NCCL_TOPO_MAX_LINKS 32
#define NCCL_TOPO_MAX_HOPS (NCCL_TOPO_MAX_NODES*NCCL_TOPO_NODE_TYPES)
#define SELECT_PATH 1
#define SELECT_LAST 2
#define NET_GDR_MASK 0x70000000
struct ncclTopoLinkList {
struct ncclTopoLink* list[NCCL_TOPO_MAX_HOPS];
int count;
int width;
float width;
int type;
};
#define NCCL_TOPO_CPU_INTEL_BDW 1
#define NCCL_TOPO_CPU_INTEL_SKL 2
#define NCCL_TOPO_UNDEF (-1)
struct ncclTopoNode {
int type;
int64_t id;
int rank;
// Type specific data
union {
struct {
int dev; // NVML dev number
int rank;
int cudaCompCap;
int gdrSupport;
}gpu;
struct {
uint64_t asic;
int port;
float width;
int gdrSupport;
int collSupport;
int maxChannels;
}net;
struct {
int arch;
int vendor;
int model;
cpu_set_t affinity;
}cpu;
};
int nlinks;
struct ncclTopoLink links[NCCL_TOPO_MAX_LINKS];
// Pre-computed paths to GPUs and NICs
@@ -79,60 +116,29 @@ struct ncclTopoNodeSet {
struct ncclTopoSystem {
struct ncclTopoNodeSet nodes[NCCL_TOPO_NODE_TYPES];
int maxSpeed;
int maxWidth;
int searchInitDone;
float maxWidth;
};
static ncclResult_t ncclTopoCreateNode(struct ncclTopoSystem* system, struct ncclTopoNode** node, int type, uint64_t id) {
ncclResult_t ncclTopoGetNode(struct ncclTopoSystem* system, struct ncclTopoNode** node, int type, uint64_t id);
ncclResult_t ncclTopoCreateNode(struct ncclTopoSystem* system, struct ncclTopoNode** node, int type, uint64_t id);
ncclResult_t ncclTopoRemoveNode(struct ncclTopoSystem* system, int type, int id);
ncclResult_t ncclTopoConnectNodes(struct ncclTopoNode* node, struct ncclTopoNode* remNode, int type, float width);
ncclResult_t ncclTopoPrintPaths(struct ncclTopoSystem* system);
ncclResult_t ncclTopoLoadSystem(const char* xmlTopoFile, struct ncclTopoSystem* system);
ncclResult_t ncclTopoGetSystemFromXml(struct ncclXml* xml, struct ncclTopoSystem** topoSystem);
ncclResult_t ncclTopoGetGraphFromXml(struct ncclXmlNode *xmlGraphs, struct ncclTopoSystem* system, struct ncclTopoGraph* graph);
ncclResult_t ncclTopoGetXmlFromGraphs(int ngraphs, struct ncclTopoGraph** graphs, struct ncclTopoSystem* system, struct ncclXml *xml);
static ncclResult_t ncclTopoIdToIndex(struct ncclTopoSystem* system, int type, int64_t id, int* index) {
*index = -1;
for (int i=0; i<system->nodes[type].count; i++) {
if (system->nodes[type].nodes[i].id == id) {
*node = system->nodes[type].nodes+i;
*index = i;
return ncclSuccess;
}
}
if (system->nodes[type].count == NCCL_TOPO_MAX_NODES) {
WARN("Error : tried to create too many nodes of type %d\n", type);
return ncclInternalError;
}
struct ncclTopoNode* n = system->nodes[type].nodes+system->nodes[type].count;
system->nodes[type].count++;
n->type = type;
n->id = id;
if (type == GPU) {
// Create link to itself (used in some corner cases)
n->nlinks=1;
n->links[0].type = LINK_LOC;
n->links[0].remNode = n;
n->links[0].width = LOC_WIDTH;
}
*node = n;
return ncclSuccess;
return ncclInternalError;
}
static ncclResult_t ncclTopoConnectNodes(struct ncclTopoNode* node, struct ncclTopoNode* remNode, int type, int width) {
// Aggregate links into higher width for NVLink
struct ncclTopoLink* link;
for (link = node->links; link->remNode; link++) {
if (link->remNode == remNode && link->type == type) break;
}
if (link->remNode == NULL) node->nlinks++;
link->type = type;
link->remNode = remNode;
link->width += width;
// Sort links in BW descending order
struct ncclTopoLink linkSave;
memcpy(&linkSave, link, sizeof(struct ncclTopoLink));
while (link != node->links) {
if ((link-1)->width >= linkSave.width) break;
memcpy(link, link-1, sizeof(struct ncclTopoLink));
link--;
}
memcpy(link, &linkSave, sizeof(struct ncclTopoLink));
return ncclSuccess;
}
ncclResult_t ncclTopoPrintPaths(struct ncclTopoSystem* system);
#endif
src/graph/tuning.cc
+68 -33
Visa fil
@@ -1,5 +1,5 @@
/*************************************************************************
* Copyright (c) 2016-2019, NVIDIA CORPORATION. All rights reserved.
* Copyright (c) 2016-2020, NVIDIA CORPORATION. All rights reserved.
*
* See LICENSE.txt for license information
************************************************************************/
@@ -52,12 +52,12 @@ ncclResult_t parseList(const char* str, const char* elems[], int nelems, int* li
}
static const char* ncclFuncStr[] = { "Broadcast", "Reduce", "AllGather", "ReduceScatter", "AllReduce" };
static const char* ncclAlgoStr[] = { "Tree", "Ring" };
static const char* ncclAlgoStr[] = { "Tree", "Ring", "CollNet" };
static const char* ncclProtoStr[] = { "LL", "LL128", "Simple" };
// Latencies in us, Bandwidths in GB/s
// Tree { LL, LL128, Simple } , Ring { LL, LL128, Simple }
static const float baseLat [NCCL_NUM_ALGORITHMS][NCCL_NUM_PROTOCOLS] = { { 4.4, 4.4, 0 }, { 3.6, 3.6, 8.4 } };
static const float baseLat [NCCL_NUM_ALGORITHMS][NCCL_NUM_PROTOCOLS] = { { 4.4, 4.4, 0 }, { 3.6, 3.6, 8.4 }, { 4.4, 4.4, 0 } };
// NVLink, PCI, Network
#define NCCL_HW_NVLINK 0
@@ -66,29 +66,32 @@ static const float baseLat [NCCL_NUM_ALGORITHMS][NCCL_NUM_PROTOCOLS] = { { 4.4,
// Tree/Simple is the latency a 256kB chunk, which is ~ base lat + 256k/12GB/s (+ 256k/12GB/s for the network).
static const float hwLat [3][NCCL_NUM_ALGORITHMS][NCCL_NUM_PROTOCOLS] =
{ /* NVLINK */
{ /* Tree (LL/LL128/Simple)*/ { .5, 1.9, 28 }, /* Ring (LL/LL128/Simple)*/ { .4, 2.5, 5.7 } },
{ /* Tree (LL/LL128/Simple)*/ { .5, 1.9, 28 }, /* Ring (LL/LL128/Simple)*/ { .4, 2.5, 5.7 }, /* CollNet (LL/LL128/Simple)*/ { .5, 1.9, 4.0 } },
/* PCI */
{ /* Tree (LL/LL128/Simple)*/ { 1.0, 1.9, 28 }, /* Ring (LL/LL128/Simple)*/ { 1.0, 2.5, 5.7 } },
{ /* Tree (LL/LL128/Simple)*/ { 1.0, 1.9, 28 }, /* Ring (LL/LL128/Simple)*/ { 1.0, 2.5, 5.7 }, /* CollNet (LL/LL128/Simple)*/ { 1.0, 1.9, 5.5 } },
/* NET */
{ /* Tree (LL/LL128/Simple)*/ { 5.0, 7.5, 50 }, /* Ring (LL/LL128/Simple)*/ { .9, 2.5, 6.6 } }
{ /* Tree (LL/LL128/Simple)*/ { 5.0, 7.5, 50 }, /* Ring (LL/LL128/Simple)*/ { .9, 2.5, 6.6 }, /* CollNet (LL/LL128/Simple)*/ { 5.0, 5.0, 10.7 } }
};
// LL128 max BW for the different collectives
static const double ll128MaxBw[NCCL_NUM_FUNCTIONS] = { 113.0, 72.0, 110.0, 91.0, 100.0 };
ncclResult_t ncclSetThresholds(struct ncclComm* comm, int minCompCap, int maxCompCap, struct ncclTopoGraph* treeGraph, struct ncclTopoGraph* ringGraph) {
int simpleDefaultThreads = (treeGraph->speedIntra*treeGraph->nChannels <= 12) ? 256 : NCCL_MAX_NTHREADS;
comm->maxThreads[NCCL_PROTO_SIMPLE] = getNthreads("NCCL_NTHREADS", ncclParamNthreads(), 2*WARP_SIZE, NCCL_MAX_NTHREADS, simpleDefaultThreads);
comm->maxThreads[NCCL_PROTO_LL] = getNthreads("NCCL_NTHREADS", ncclParamNthreads(), 2*WARP_SIZE, NCCL_MAX_NTHREADS, NCCL_MAX_NTHREADS);
comm->maxThreads[NCCL_PROTO_LL128] = getNthreads("NCCL_LL128_NTHREADS", ncclParamLl128Nthreads(), NCCL_LL128_MAX_NTHREADS/4, NCCL_LL128_MAX_NTHREADS, NCCL_LL128_MAX_NTHREADS);
INFO(NCCL_INIT, "Threads per block : %d/%d/%d", comm->maxThreads[NCCL_PROTO_LL], comm->maxThreads[NCCL_PROTO_LL128], comm->maxThreads[NCCL_PROTO_SIMPLE]);
ncclResult_t ncclTopoSetThresholds(struct ncclComm* comm, int minCompCap, int maxCompCap, struct ncclTopoGraph* treeGraph, struct ncclTopoGraph* ringGraph, struct ncclTopoGraph* collNetGraph) {
int simpleDefaultThreads = (ringGraph->speedIntra*ringGraph->nChannels <= PCI_WIDTH) ? 256 : NCCL_MAX_NTHREADS;
comm->maxThreads[NCCL_ALGO_RING][NCCL_PROTO_SIMPLE] =
getNthreads("NCCL_NTHREADS", ncclParamNthreads(), 2*WARP_SIZE, NCCL_MAX_NTHREADS, simpleDefaultThreads);
comm->maxThreads[NCCL_ALGO_TREE][NCCL_PROTO_SIMPLE] = comm->maxThreads[NCCL_ALGO_COLLNET][NCCL_PROTO_SIMPLE] =
getNthreads("NCCL_NTHREADS", ncclParamNthreads(), 2*WARP_SIZE, NCCL_MAX_NTHREADS, NCCL_MAX_NTHREADS);
comm->maxThreads[NCCL_ALGO_RING][NCCL_PROTO_LL] = comm->maxThreads[NCCL_ALGO_TREE][NCCL_PROTO_LL] = comm->maxThreads[NCCL_ALGO_COLLNET][NCCL_PROTO_LL] =
getNthreads("NCCL_NTHREADS", ncclParamNthreads(), 2*WARP_SIZE, NCCL_MAX_NTHREADS, NCCL_MAX_NTHREADS);
comm->maxThreads[NCCL_ALGO_RING][NCCL_PROTO_LL128] = comm->maxThreads[NCCL_ALGO_TREE][NCCL_PROTO_LL128] = comm->maxThreads[NCCL_ALGO_COLLNET][NCCL_PROTO_LL128] =
getNthreads("NCCL_LL128_NTHREADS", ncclParamLl128Nthreads(), NCCL_LL128_MAX_NTHREADS/4, NCCL_LL128_MAX_NTHREADS, NCCL_LL128_MAX_NTHREADS);
if (comm->nRanks <= 1) return ncclSuccess;
struct ncclTopoGraph* graphs[2] = { treeGraph, ringGraph };
int intraHw[2], hw[2];
for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) intraHw[a] = graphs[a]->nvlink ? NCCL_HW_NVLINK : NCCL_HW_PCI;
struct ncclTopoGraph* graphs[NCCL_NUM_ALGORITHMS] = { treeGraph, ringGraph, collNetGraph };
int intraHw[NCCL_NUM_ALGORITHMS], hw[NCCL_NUM_ALGORITHMS];
for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) intraHw[a] = graphs[a]->typeIntra == LINK_NVL ? NCCL_HW_NVLINK : NCCL_HW_PCI;
for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) hw[a] = comm->nNodes == 1 ? intraHw[a] : NCCL_HW_NET;
for (int coll=0; coll<NCCL_NUM_FUNCTIONS; coll++) {
@@ -97,21 +100,24 @@ ncclResult_t ncclSetThresholds(struct ncclComm* comm, int minCompCap, int maxCom
comm->nRanks;
for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) {
if (coll != ncclCollAllReduce && a == NCCL_ALGO_TREE) continue;
if (coll != ncclCollAllReduce && a != NCCL_ALGO_RING) continue;
for (int p=0; p<NCCL_NUM_PROTOCOLS; p++) {
int speed = comm->nNodes <= 2 ? graphs[a]->speedIntra : graphs[a]->speedInter;
float busBw = graphs[a]->nChannels * speed * 1.0;
float speed = comm->nNodes <= 2 || a == NCCL_ALGO_COLLNET ? graphs[a]->speedIntra : graphs[a]->speedInter;
float busBw = graphs[a]->nChannels * speed;
// Various model refinements
if (a == NCCL_ALGO_RING && p == NCCL_PROTO_LL) busBw *= 1.0/4.0;
if (a == NCCL_ALGO_RING && p == NCCL_PROTO_LL128) busBw = std::min(busBw*120.0/128.0, ll128MaxBw[coll]);
if (a == NCCL_ALGO_TREE) busBw = std::min(busBw*.9, comm->nNodes > 1 ? 70.0 : 90.0);
if (a == NCCL_ALGO_TREE) busBw = std::min(busBw*.9, comm->nNodes > 2 ? 80.0 : 110.0);
if (a == NCCL_ALGO_TREE && p == NCCL_PROTO_LL) busBw *= 1.0/3.0;
if (a == NCCL_ALGO_TREE && p == NCCL_PROTO_LL128) busBw *= 7.0/9.0;
if (a == NCCL_ALGO_COLLNET) busBw *= .9;
if (a == NCCL_ALGO_COLLNET && p == NCCL_PROTO_LL) busBw *= 1.0/6.0; // Take into account that GDR read is disabled on both sides
if (a == NCCL_ALGO_COLLNET && p == NCCL_PROTO_LL128) busBw = 0; // CollNet does not support LL128
// Convert bus BW to algorithm BW
float ratio = a == NCCL_ALGO_TREE ? .5 : (1.0 * comm->nRanks) / nsteps;
float ratio = (a != NCCL_ALGO_RING) ? .5 : (1.0 * comm->nRanks) / nsteps;
comm->bandwidths[coll][a][p] = busBw * ratio;
comm->latencies[coll][a][p] = baseLat[a][p];
@@ -127,11 +133,16 @@ ncclResult_t ncclSetThresholds(struct ncclComm* comm, int minCompCap, int maxCom
} else {
comm->latencies[coll][a][p] += nsteps*lat;
}
} else {
} else if (a == NCCL_ALGO_TREE) {
float intraLat = hwLat[intraHw[a]][a][p];
float interLat = hwLat[NCCL_HW_NET][a][p];
comm->latencies[coll][a][p] +=
2 * ((comm->nRanks/comm->nNodes-1) * intraLat + log2i(comm->nNodes) * interLat);
} else {
float intraLat = hwLat[intraHw[a]][a][p];
float interLat = hwLat[NCCL_HW_NET][a][p];
comm->latencies[coll][a][p] +=
2 * (comm->nRanks/comm->nNodes-1) * intraLat + interLat;
}
}
}
@@ -140,7 +151,7 @@ ncclResult_t ncclSetThresholds(struct ncclComm* comm, int minCompCap, int maxCom
// Protocols/Algorithms enable/disable, and user overrides.
// All are enabled except ll128 which is enabled by default only in certain cases.
int protoEnable[NCCL_NUM_PROTOCOLS] = { 1, 2, 1 };
int algoEnable[NCCL_NUM_ALGORITHMS] = { 1, 1 };
int algoEnable[NCCL_NUM_ALGORITHMS] = { 1, 1, 1 };
const char *protoStr = getenv("NCCL_PROTO");
if (protoStr) NCCLCHECK(parseList(protoStr, ncclProtoStr, NCCL_NUM_PROTOCOLS, protoEnable));
@@ -151,30 +162,32 @@ ncclResult_t ncclSetThresholds(struct ncclComm* comm, int minCompCap, int maxCom
int pEnable = protoEnable[p];
if (pEnable == 2 && p == NCCL_PROTO_LL128) {
// Enable LL128 by default only on Volta+NVLink. Other cases are not tested and may cause silent data corruption.
pEnable = (graphs[a]->type <= LINK_PCI) && graphs[a]->nvlink && minCompCap == 70 && maxCompCap == 70 ? 1 : 0;
pEnable = (graphs[a]->typeInter <= LINK_PCI) && graphs[a]->typeIntra == LINK_NVL && minCompCap == 70 && maxCompCap == 70 ? 1 : 0;
}
if (pEnable == 0 || algoEnable[a] == 0) comm->bandwidths[c][a][p] = 0;
}
if (comm->rank == 0) {
char line[1024];
int offset = 0;
sprintf(line, "Latency/AlgBw |");
offset = strlen(line);
for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) {
for (int p=0; p<NCCL_NUM_PROTOCOLS; p++) {
sprintf(line+offset, " %4s/%6s |", ncclAlgoStr[a], ncclProtoStr[p]);
offset = strlen(line);
sprintf(line+strlen(line), " %7s/%6s |", ncclAlgoStr[a], ncclProtoStr[p]);
}
}
INFO(NCCL_TUNING, "%s", line);
sprintf(line, " Max NThreads |");
for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) {
for (int p=0; p<NCCL_NUM_PROTOCOLS; p++) {
sprintf(line+strlen(line), " %14d |", comm->maxThreads[a][p]);
}
}
INFO(NCCL_TUNING, "%s", line);
for (int c=0; c<NCCL_NUM_FUNCTIONS; c++) {
sprintf(line, "%13s |", ncclFuncStr[c]);
offset = strlen(line);
for (int a=0; a<NCCL_NUM_ALGORITHMS; a++) {
for (int p=0; p<NCCL_NUM_PROTOCOLS; p++) {
sprintf(line+offset, "%7.1f/%5.1f|", comm->latencies[c][a][p], comm->bandwidths[c][a][p]);
offset = strlen(line);
sprintf(line+strlen(line), "%8.1f/%6.1f |", comm->latencies[c][a][p], comm->bandwidths[c][a][p]);
}
}
INFO(NCCL_TUNING, "%s", line);
@@ -201,12 +214,34 @@ ncclResult_t ncclSetThresholds(struct ncclComm* comm, int minCompCap, int maxCom
}
}
INFO(NCCL_INIT, "threadThresholds %ld/%ld/%ld | %ld/%ld/%ld",
INFO(NCCL_INIT, "threadThresholds %ld/%ld/%ld | %ld/%ld/%ld | %ld/%ld/%ld",
comm->threadThresholds[NCCL_ALGO_TREE][NCCL_PROTO_LL],
comm->threadThresholds[NCCL_ALGO_TREE][NCCL_PROTO_LL128],
comm->threadThresholds[NCCL_ALGO_TREE][NCCL_PROTO_SIMPLE],
comm->threadThresholds[NCCL_ALGO_RING][NCCL_PROTO_LL],
comm->threadThresholds[NCCL_ALGO_RING][NCCL_PROTO_LL128],
comm->threadThresholds[NCCL_ALGO_RING][NCCL_PROTO_SIMPLE]);
comm->threadThresholds[NCCL_ALGO_RING][NCCL_PROTO_SIMPLE],
comm->threadThresholds[NCCL_ALGO_COLLNET][NCCL_PROTO_LL],
comm->threadThresholds[NCCL_ALGO_COLLNET][NCCL_PROTO_LL128],
comm->threadThresholds[NCCL_ALGO_COLLNET][NCCL_PROTO_SIMPLE]);
return ncclSuccess;
}
// Trees are not perfectly sticking to the model for medium sizes. Applying a static correction
// factor is not ideal but works quite well. Powers of two, 64 B to 1 GB.
static float treeCorrectionFactor[NCCL_NUM_PROTOCOLS][22] = {
{ 1.0, 1.0, 1.0, 1.0, .9, .8, .7, .7, .7, .7, .6, .5, .5, .5, .6, .7, .8, .9, .9, 1.0, 1.0, 1.0 },
{ 1.0, 1.0, 1.0, 1.0, 1.0, .9, .8, .8, .8, .8, .7, .7, .7, .6, .6, .7, .7, .8, .8, .9, .9, 1.0 },
{ .9, .9, .9, .9, .9, .9, .9, .8, .7, .6, .6, .5, .5, .5, .5, .5, .5, .6, .6, .7, .8, .9 }
};
ncclResult_t ncclTopoGetAlgoTime(struct ncclInfo* info, int algorithm, int protocol, float* time) {
float bw = info->comm->bandwidths[info->coll][algorithm][protocol];
if (bw == 0) {
*time = -1.0; return ncclSuccess;
}
int logSize = log2i(info->nBytes>>6);
if (algorithm == NCCL_ALGO_TREE && logSize < 22) bw *= treeCorrectionFactor[protocol][logSize];
*time = info->comm->latencies[info->coll][algorithm][protocol] + (info->nBytes) / (1000 * bw);
return ncclSuccess;
}
src/graph/xml.cc
+780
Visa fil
@@ -0,0 +1,780 @@
/*************************************************************************
* Copyright (c) 2019-2020, NVIDIA CORPORATION. All rights reserved.
*
* See LICENSE.txt for license information
************************************************************************/
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <ctype.h>
#include "core.h"
#include "nvmlwrap.h"
#include "xml.h"
/*******************/
/* XML File Parser */
/*******************/
ncclResult_t xmlGetChar(FILE* file, char* c) {
if (fread(c, 1, 1, file) == 0) {
WARN("XML Parse : Unexpected EOF");
return ncclInternalError;
}
return ncclSuccess;
}
ncclResult_t xmlGetValue(FILE* file, char* value, char* last) {
char c;
NCCLCHECK(xmlGetChar(file, &c));
if (c != '"' && c != '\'') {
#if INT_OK
int o = 0;
do {
value[o++] = c;
NCCLCHECK(xmlGetChar(file, &c));
} while (c >= '0' && c <= '9');
value[o] = '\0';
*last = c;
return ncclSuccess;
#else
WARN("XML Parse : Expected (double) quote.");
return ncclInternalError;
#endif
}
int o = 0;
do {
NCCLCHECK(xmlGetChar(file, &c));
value[o++] = c;
} while (c != '"');
value[o-1] = '\0';
NCCLCHECK(xmlGetChar(file, last));
return ncclSuccess;
}
ncclResult_t xmlGetToken(FILE* file, char* name, char* value, char* last) {
char c;
char* ptr = name;
int o = 0;
do {
NCCLCHECK(xmlGetChar(file, &c));
if (c == '=') {
ptr[o] = '\0';
if (value == NULL) {
WARN("XML Parse : Unexpected value with name %s\n", ptr);
return ncclInternalError;
}
return xmlGetValue(file, value, last);
}
ptr[o] = c;
if (o == MAX_STR_LEN-1) {
ptr[o] = '\0';
WARN("Error : name %s too long (max %d)", ptr, MAX_STR_LEN);
return ncclInternalError;
}
o++;
} while (c != ' ' && c != '>' && c != '/' && c != '\n' && c != '\r');
ptr[o-1] = '\0';
*last = c;
return ncclSuccess;
}
// Shift the 3-chars string by one char and append c at the end
#define SHIFT_APPEND(s, c) do { s[0]=s[1]; s[1]=s[2]; s[2]=c; } while(0)
ncclResult_t xmlSkipComment(FILE* file, char* start, char next) {
// Start from something neutral with \0 at the end.
char end[4] = "...";
// Inject all trailing chars from previous reads. We don't need
// to check for --> here because there cannot be a > in the name.
for (int i=0; i<strlen(start); i++) SHIFT_APPEND(end, start[i]);
SHIFT_APPEND(end, next);
// Stop when we find "-->"
while (strcmp(end, "-->") != 0) {
int c;
if (fread(&c, 1, 1, file) != 1) {
WARN("XML Parse error : unterminated comment");
return ncclInternalError;
}
SHIFT_APPEND(end, c);
}
return ncclSuccess;
}
ncclResult_t xmlGetNode(FILE* file, struct ncclXmlNode* node) {
node->type = NODE_TYPE_NONE;
char c = ' ';
while (c == ' ' || c == '\n' || c == '\r') {
if (fread(&c, 1, 1, file) == 0) return ncclSuccess;
}
if (c != '<') {
WARN("XML Parse error : expecting '<', got '%c'", c);
return ncclInternalError;
}
// Read XML element name
NCCLCHECK(xmlGetToken(file, node->name, NULL, &c));
// Check for comments
if (strncmp(node->name, "!--", 3) == 0) {
NCCLCHECK(xmlSkipComment(file, node->name+3, c));
return xmlGetNode(file, node);
}
// Check for closing tag
if (node->name[0] == '\0' && c == '/') {
node->type = NODE_TYPE_CLOSE;
// Re-read the name, we got '/' in the first call
NCCLCHECK(xmlGetToken(file, node->name, NULL, &c));
if (c != '>') {
WARN("XML Parse error : unexpected trailing %c in closing tag %s\n", c, node->name);
return ncclInternalError;
}
return ncclSuccess;
}
node->type = NODE_TYPE_OPEN;
// Get Attributes
int a = 0;
while (c == ' ') {
NCCLCHECK(xmlGetToken(file, node->attrs[a].key, node->attrs[a].value, &c));
if (a == MAX_ATTR_COUNT) {
INFO(NCCL_GRAPH, "XML Parse : Ignoring extra attributes (max %d)\n", MAX_ATTR_COUNT);
// Actually we need to still consume the extra attributes so we have an extra one.
} else a++;
}
node->nAttrs = a;
if (c == '/') {
node->type = NODE_TYPE_SINGLE;
char str[MAX_STR_LEN];
NCCLCHECK(xmlGetToken(file, str, NULL, &c));
}
if (c != '>') {
WARN("XML Parse : expected >, got '%c'", c);
return ncclInternalError;
}
return ncclSuccess;
}
typedef ncclResult_t (*xmlHandlerFunc_t)(FILE*, struct ncclXml*, struct ncclXmlNode*);
struct xmlHandler {
const char * name;
xmlHandlerFunc_t func;
};
ncclResult_t xmlLoadSub(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head, struct xmlHandler handlers[], int nHandlers) {
if (head && head->type == NODE_TYPE_SINGLE) return ncclSuccess;
while (1) {
if (xml->maxIndex == MAX_NODES) {
WARN("Error : XML parser is limited to 1024 nodes\n");
return ncclInternalError;
}
struct ncclXmlNode* node = xml->nodes+xml->maxIndex;
memset(node, 0, sizeof(struct ncclXmlNode));
NCCLCHECK(xmlGetNode(file, node));
if (node->type == NODE_TYPE_NONE) {
if (head) {
WARN("XML Parse : unterminated %s", head->name);
return ncclInternalError;
} else {
// All done
return ncclSuccess;
}
}
if (head && node->type == NODE_TYPE_CLOSE) {
if (strcmp(node->name, head->name) != 0) {
WARN("XML Mismatch : %s / %s", head->name, node->name);
return ncclInternalError;
}
return ncclSuccess;
}
int found = 0;
for (int h=0; h<nHandlers; h++) {
if (strcmp(node->name, handlers[h].name) == 0) {
if (head) head->subs[head->nSubs++] = node;
node->parent = head;
node->nSubs = 0;
xml->maxIndex++;
NCCLCHECK(handlers[h].func(file, xml, node));
found = 1;
break;
}
}
if (!found) {
if (nHandlers) INFO(NCCL_GRAPH, "Ignoring element %s", node->name);
NCCLCHECK(xmlLoadSub(file, xml, node, NULL, 0));
}
}
}
/**************/
/* XML Writer */
/**************/
ncclResult_t ncclTopoDumpXmlRec(int indent, FILE* file, struct ncclXmlNode* node) {
for (int i=0; i<indent; i++) fprintf(file, " ");
fprintf(file, "<%s", node->name);
for (int a=0; a<node->nAttrs; a++) {
fprintf(file, " %s=\"%s\"", node->attrs[a].key, node->attrs[a].value);
}
if (node->nSubs == 0) {
fprintf(file, "/>\n");
} else {
fprintf(file, ">\n");
for (int s=0; s<node->nSubs; s++) {
NCCLCHECK(ncclTopoDumpXmlRec(indent+2, file, node->subs[s]));
}
for (int i=0; i<indent; i++) fprintf(file, " ");
fprintf(file, "</%s>\n", node->name);
}
return ncclSuccess;
}
ncclResult_t ncclTopoDumpXmlToFile(const char* xmlTopoFile, struct ncclXml* xml) {
FILE* file = fopen(xmlTopoFile, "w");
if (file == NULL) {
WARN("Unable to open %s, not dumping topology.", xmlTopoFile);
return ncclSuccess;
}
NCCLCHECK(ncclTopoDumpXmlRec(0, file, xml->nodes));
fclose(file);
return ncclSuccess;
}
/****************************************/
/* Parser rules for our specific format */
/****************************************/
ncclResult_t ncclTopoXmlLoadNvlink(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head) {
NCCLCHECK(xmlLoadSub(file, xml, head, NULL, 0));
return ncclSuccess;
}
ncclResult_t ncclTopoXmlLoadGpu(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head) {
struct xmlHandler handlers[] = { { "nvlink", ncclTopoXmlLoadNvlink } };
NCCLCHECK(xmlLoadSub(file, xml, head, handlers, 1));
return ncclSuccess;
}
ncclResult_t ncclTopoXmlLoadNet(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head) {
NCCLCHECK(xmlLoadSub(file, xml, head, NULL, 0));
return ncclSuccess;
}
ncclResult_t ncclTopoXmlLoadNic(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head) {
struct xmlHandler handlers[] = { { "net", ncclTopoXmlLoadNet } };
NCCLCHECK(xmlLoadSub(file, xml, head, handlers, 1));
return ncclSuccess;
}
ncclResult_t ncclTopoXmlLoadPci(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head) {
struct xmlHandler handlers[] = { { "pci", ncclTopoXmlLoadPci }, { "gpu", ncclTopoXmlLoadGpu }, { "nic", ncclTopoXmlLoadNic} };
NCCLCHECK(xmlLoadSub(file, xml, head, handlers, 3));
return ncclSuccess;
}
ncclResult_t ncclTopoXmlLoadCpu(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head) {
struct xmlHandler handlers[] = { { "pci", ncclTopoXmlLoadPci }, { "nic", ncclTopoXmlLoadNic } };
NCCLCHECK(xmlLoadSub(file, xml, head, handlers, 2));
return ncclSuccess;
}
ncclResult_t ncclTopoXmlLoadSystem(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head) {
int version;
NCCLCHECK(xmlGetAttrInt(head, "version", &version));
if (version != NCCL_TOPO_XML_VERSION) {
WARN("XML Topology has wrong version %d, %d needed", version, NCCL_TOPO_XML_VERSION);
return ncclInvalidUsage;
}
const char* name;
NCCLCHECK(xmlGetAttr(head, "name", &name));
if (name != NULL) INFO(NCCL_GRAPH, "Loading topology %s", name);
else INFO(NCCL_GRAPH, "Loading unnamed topology");
struct xmlHandler handlers[] = { { "cpu", ncclTopoXmlLoadCpu } };
NCCLCHECK(xmlLoadSub(file, xml, head, handlers, 1));
return ncclSuccess;
}
ncclResult_t ncclTopoGetXmlFromFile(const char* xmlTopoFile, struct ncclXml* xml) {
FILE* file = fopen(xmlTopoFile, "r");
if (file == NULL) {
WARN("Could not open XML topology file %s : %s", xmlTopoFile, strerror(errno));
return ncclSuccess;
}
struct xmlHandler handlers[] = { { "system", ncclTopoXmlLoadSystem } };
xml->maxIndex = 0;
NCCLCHECK(xmlLoadSub(file, xml, NULL, handlers, 1));
fclose(file);
return ncclSuccess;
}
/**********************/
/* XML creation */
/* from autodetection */
/**********************/
#define BUSID_SIZE (sizeof("0000:00:00.0"))
#define BUSID_REDUCED_SIZE (sizeof("0000:00"))
static void memcpylower(char* dst, const char* src, const size_t size) {
for (int i=0; i<size; i++) dst[i] = tolower(src[i]);
}
static ncclResult_t getPciPath(const char* busId, char** path) {
char busPath[] = "/sys/class/pci_bus/0000:00/../../0000:00:00.0";
memcpylower(busPath+sizeof("/sys/class/pci_bus/")-1, busId, BUSID_REDUCED_SIZE-1);
memcpylower(busPath+sizeof("/sys/class/pci_bus/0000:00/../../")-1, busId, BUSID_SIZE-1);
*path = realpath(busPath, NULL);
if (*path == NULL) {
WARN("Could not find real path of %s", busPath);
return ncclSystemError;
}
return ncclSuccess;
}
ncclResult_t ncclTopoGetStrFromSys(const char* path, const char* fileName, char* strValue) {
char filePath[PATH_MAX];
sprintf(filePath, "%s/%s", path, fileName);
int offset = 0;
FILE* file;
if ((file = fopen(filePath, "r")) != NULL) {
while (feof(file) == 0 && ferror(file) == 0 && offset < MAX_STR_LEN) {
int len = fread(strValue+offset, 1, MAX_STR_LEN-offset, file);
offset += len;
}
fclose(file);
}
if (offset == 0) {
strValue[0] = '\0';
INFO(NCCL_GRAPH, "Topology detection : could not read %s, ignoring", filePath);
} else {
strValue[offset-1] = '\0';
}
return ncclSuccess;
}
ncclResult_t ncclTopoSetAttrFromSys(struct ncclXmlNode* pciNode, const char* path, const char* fileName, const char* attrName) {
char strValue[MAX_STR_LEN];
NCCLCHECK(ncclTopoGetStrFromSys(path, fileName, strValue));
if (strValue[0] != '\0') { NCCLCHECK(xmlSetAttr(pciNode, attrName, strValue)); }
TRACE(NCCL_GRAPH, "Read from sys %s/%s -> %s=%s\n", path, fileName, attrName, strValue);
return ncclSuccess;
}
ncclResult_t ncclTopoGetXmlFromCpu(struct ncclXmlNode* cpuNode, struct ncclXml* xml) {
int index;
NCCLCHECK(xmlGetAttrIndex(cpuNode, "affinity", &index));
if (index == -1) {
const char* numaId;
NCCLCHECK(xmlGetAttr(cpuNode, "numaid", &numaId));
if (numaId == NULL) {
WARN("GetXmlFromCpu : could not find CPU numa ID.");
return ncclInternalError;
}
// Set affinity
char cpumaskPath[] = "/sys/devices/system/node/node0000";
sprintf(cpumaskPath, "/sys/devices/system/node/node%s", numaId);
NCCLCHECK(ncclTopoSetAttrFromSys(cpuNode, cpumaskPath, "cpumap", "affinity"));
}
NCCLCHECK(xmlGetAttrIndex(cpuNode, "arch", &index));
if (index == -1) {
// Fill CPU type / vendor / model
#if defined(__PPC__)
NCCLCHECK(xmlSetAttr(cpuNode, "arch", "ppc64"));
#elif defined(__aarch64__)
NCCLCHECK(xmlSetAttr(cpuNode, "arch", "arm64"));
#elif defined(__x86_64__)
NCCLCHECK(xmlSetAttr(cpuNode, "arch", "x86_64"));
#endif
}
#if defined(__x86_64__)
NCCLCHECK(xmlGetAttrIndex(cpuNode, "vendor", &index));
if (index == -1) {
union {
struct {
// CPUID 0 String register order
uint32_t ebx;
uint32_t edx;
uint32_t ecx;
};
char vendor[12];
} cpuid0;
asm volatile("cpuid" : "=b" (cpuid0.ebx), "=c" (cpuid0.ecx), "=d" (cpuid0.edx) : "a" (0) : "memory");
char vendor[13];
strncpy(vendor, cpuid0.vendor, 12);
vendor[12] = '\0';
NCCLCHECK(xmlSetAttr(cpuNode, "vendor", vendor));
}
NCCLCHECK(xmlGetAttrIndex(cpuNode, "familyid", &index));
if (index == -1) {
union {
struct {
unsigned steppingId:4;
unsigned modelId:4;
unsigned familyId:4;
unsigned processorType:2;
unsigned resv0:2;
unsigned extModelId:4;
unsigned extFamilyId:8;
unsigned resv1:4;
};
uint32_t val;
} cpuid1;
asm volatile("cpuid" : "=a" (cpuid1.val) : "a" (1) : "memory");
int familyId = cpuid1.familyId + (cpuid1.extFamilyId << 4);
int modelId = cpuid1.modelId + (cpuid1.extModelId << 4);
NCCLCHECK(xmlSetAttrInt(cpuNode, "familyid", familyId));
NCCLCHECK(xmlSetAttrInt(cpuNode, "modelid", modelId));
}
#endif
return ncclSuccess;
}
ncclResult_t ncclTopoGetPciNode(struct ncclXml* xml, const char* busId, struct ncclXmlNode** pciNode) {
NCCLCHECK(xmlFindTagKv(xml, "pci", pciNode, "busid", busId));
if (*pciNode == NULL) {
NCCLCHECK(xmlAddNode(xml, NULL, "pci", pciNode));
}
NCCLCHECK(xmlSetAttr(*pciNode, "busid", busId));
return ncclSuccess;
}
// Check whether a string is in BDF format or not.
// BDF (Bus-Device-Function) is "BBBB:BB:DD.F" where B, D and F are hex digits.
// There can be trailing chars.
int isHex(char c) { return ((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F')); }
int checkBDFFormat(char* bdf) {
if (bdf[4] != ':' || bdf[7] != ':' || bdf[10] != '.') return 0;
if (isHex(bdf[0]) == 0 || isHex(bdf[1] == 0) || isHex(bdf[2] == 0) || isHex(bdf[3] == 0) ||
isHex(bdf[5] == 0) || isHex(bdf[6] == 0) || isHex(bdf[8] == 0) || isHex(bdf[9] == 0) ||
isHex(bdf[11] == 0)) return 0;
return 1;
}
ncclResult_t ncclTopoGetXmlFromSys(struct ncclXmlNode* pciNode, struct ncclXml* xml) {
// Fill info, then parent
const char* busId;
NCCLCHECK(xmlGetAttr(pciNode, "busid", &busId));
char* path = NULL;
int index;
NCCLCHECK(xmlGetAttrIndex(pciNode, "class", &index));
if (index == -1) {
if (path == NULL) NCCLCHECK(getPciPath(busId, &path));
NCCLCHECK(ncclTopoSetAttrFromSys(pciNode, path, "class", "class"));
}
NCCLCHECK(xmlGetAttrIndex(pciNode, "link_speed", &index));
if (index == -1) {
if (path == NULL) NCCLCHECK(getPciPath(busId, &path));
char deviceSpeedStr[MAX_STR_LEN];
float deviceSpeed;
NCCLCHECK(ncclTopoGetStrFromSys(path, "max_link_speed", deviceSpeedStr));
sscanf(deviceSpeedStr, "%f GT/s", &deviceSpeed);
char portSpeedStr[MAX_STR_LEN];
float portSpeed;
NCCLCHECK(ncclTopoGetStrFromSys(path, "../max_link_speed", portSpeedStr));
sscanf(portSpeedStr, "%f GT/s", &portSpeed);
NCCLCHECK(xmlSetAttr(pciNode, "link_speed", portSpeed < deviceSpeed ? portSpeedStr : deviceSpeedStr));
}
NCCLCHECK(xmlGetAttrIndex(pciNode, "link_width", &index));
if (index == -1) {
if (path == NULL) NCCLCHECK(getPciPath(busId, &path));
char strValue[MAX_STR_LEN];
NCCLCHECK(ncclTopoGetStrFromSys(path, "max_link_width", strValue));
int deviceWidth = strtol(strValue, NULL, 0);
NCCLCHECK(ncclTopoGetStrFromSys(path, "../max_link_width", strValue));
int portWidth = strtol(strValue, NULL, 0);
NCCLCHECK(xmlSetAttrInt(pciNode, "link_width", std::min(deviceWidth,portWidth)));
}
struct ncclXmlNode* parent = pciNode->parent;
if (parent == NULL) {
if (path == NULL) NCCLCHECK(getPciPath(busId, &path));
// Save that for later in case next step is a CPU
char numaIdStr[MAX_STR_LEN];
NCCLCHECK(ncclTopoGetStrFromSys(path, "numa_node", numaIdStr));
// Go up one level in the PCI tree. Rewind two "/" and follow the upper PCI
// switch, or stop if we reach a CPU root complex.
int slashCount = 0;
int parentOffset;
for (parentOffset = strlen(path)-1; parentOffset>0; parentOffset--) {
if (path[parentOffset] == '/') {
slashCount++;
path[parentOffset] = '\0';
int start = parentOffset - 1;
while (start>0 && path[start] != '/') start--;
// Check whether the parent path looks like "BBBB:BB:DD.F" or not.
if (checkBDFFormat(path+start+1) == 0) {
// This a CPU root complex. Create a CPU tag and stop there.
struct ncclXmlNode* topNode;
NCCLCHECK(xmlFindTag(xml, "system", &topNode));
NCCLCHECK(xmlGetSubKv(topNode, "cpu", &parent, "numaid", numaIdStr));
if (parent == NULL) {
NCCLCHECK(xmlAddNode(xml, topNode, "cpu", &parent));
NCCLCHECK(xmlSetAttr(parent, "numaid", numaIdStr));
}
} else if (slashCount == 2) {
// Continue on the upper PCI switch
for (int i = strlen(path)-1; i>0; i--) {
if (path[i] == '/') {
NCCLCHECK(xmlFindTagKv(xml, "pci", &parent, "busid", path+i+1));
if (parent == NULL) {
NCCLCHECK(xmlAddNode(xml, NULL, "pci", &parent));
NCCLCHECK(xmlSetAttr(parent, "busid", path+i+1));
}
break;
}
}
}
}
if (parent) break;
}
pciNode->parent = parent;
parent->subs[parent->nSubs++] = pciNode;
}
if (strcmp(parent->name, "pci") == 0) {
NCCLCHECK(ncclTopoGetXmlFromSys(parent, xml));
} else if (strcmp(parent->name, "cpu") == 0) {
NCCLCHECK(ncclTopoGetXmlFromCpu(parent, xml));
}
free(path);
return ncclSuccess;
}
ncclResult_t ncclTopoGetXmlFromGpu(struct ncclXmlNode* pciNode, nvmlDevice_t nvmlDev, struct ncclXml* xml, struct ncclXmlNode** gpuNodeRet) {
struct ncclXmlNode* gpuNode = NULL;
NCCLCHECK(xmlGetSub(pciNode, "gpu", &gpuNode));
if (gpuNode == NULL) NCCLCHECK(xmlAddNode(xml, pciNode, "gpu", &gpuNode));
int index = -1;
int dev = -1;
NCCLCHECK(xmlGetAttrIndex(gpuNode, "dev", &index));
if (index == -1) {
if (nvmlDev == NULL) {
WARN("No NVML, trying to use CUDA instead");
const char* busId;
NCCLCHECK(xmlGetAttr(pciNode, "busid", &busId));
if (busId == NULL || cudaDeviceGetByPCIBusId(&dev, busId) != cudaSuccess) dev = -1;
} else {
NCCLCHECK(wrapNvmlDeviceGetIndex(nvmlDev, (unsigned int*)&dev));
}
NCCLCHECK(xmlSetAttrInt(gpuNode, "dev", dev));
}
NCCLCHECK(xmlGetAttrInt(gpuNode, "dev", &dev));
if (dev == -1) return ncclSuccess;
NCCLCHECK(xmlGetAttrIndex(gpuNode, "sm", &index));
if (index == -1) {
int cudaMajor, cudaMinor;
if (nvmlDev == NULL) {
cudaDeviceProp devProp;
CUDACHECK(cudaGetDeviceProperties(&devProp, dev));
cudaMajor = devProp.major; cudaMinor = devProp.minor;
} else {
NCCLCHECK(wrapNvmlDeviceGetCudaComputeCapability(nvmlDev, &cudaMajor, &cudaMinor));
}
NCCLCHECK(xmlSetAttrInt(gpuNode, "sm", cudaMajor*10+cudaMinor));
}
int sm;
NCCLCHECK(xmlGetAttrInt(gpuNode, "sm", &sm));
struct ncclXmlNode* nvlNode = NULL;
NCCLCHECK(xmlGetSub(pciNode, "nvlink", &nvlNode));
if (nvlNode == NULL) {
// NVML NVLink detection
int maxNvLinks = (sm < 60) ? 0 : (sm < 70) ? 4 : 6;
if (maxNvLinks > 0 && nvmlDev == NULL) {
WARN("No NVML device handle. Skipping nvlink detection.\n");
maxNvLinks = 0;
}
for (int l=0; l<maxNvLinks; ++l) {
// Check whether we can use this NVLink for P2P
unsigned canP2P;
if ((wrapNvmlDeviceGetNvLinkCapability(nvmlDev, l, NVML_NVLINK_CAP_P2P_SUPPORTED, &canP2P) != ncclSuccess) || !canP2P) continue;
// Make sure the Nvlink is up. The previous call should have trained the link.
nvmlEnableState_t isActive;
if ((wrapNvmlDeviceGetNvLinkState(nvmlDev, l, &isActive) != ncclSuccess) || (isActive != NVML_FEATURE_ENABLED)) continue;
// Try to figure out what's on the other side of the NVLink
nvmlPciInfo_t remoteProc;
if (wrapNvmlDeviceGetNvLinkRemotePciInfo(nvmlDev, l, &remoteProc) != ncclSuccess) continue;
// Make a lower case copy of the bus ID for calling ncclDeviceType
// PCI system path is in lower case
char* p = remoteProc.busId;
char lowerId[NVML_DEVICE_PCI_BUS_ID_BUFFER_SIZE];
for (int c=0; c<NVML_DEVICE_PCI_BUS_ID_BUFFER_SIZE; c++) {
lowerId[c] = tolower(p[c]);
if (p[c] == 0) break;
}
NCCLCHECK(xmlGetSubKv(gpuNode, "nvlink", &nvlNode, "target", lowerId));
if (nvlNode == NULL) {
NCCLCHECK(xmlAddNode(xml, gpuNode, "nvlink", &nvlNode));
NCCLCHECK(xmlSetAttr(nvlNode, "target", lowerId));
NCCLCHECK(xmlSetAttrInt(nvlNode, "count", 1));
} else {
int count;
NCCLCHECK(xmlGetAttrInt(nvlNode, "count", &count));
NCCLCHECK(xmlSetAttrInt(nvlNode, "count", count+1));
}
}
}
// Fill target classes
for (int s=0; s<gpuNode->nSubs; s++) {
struct ncclXmlNode* sub = gpuNode->subs[s];
if (strcmp(sub->name, "nvlink") != 0) continue;
int index;
NCCLCHECK(xmlGetAttrIndex(sub, "tclass", &index));
if (index == -1) {
const char* busId;
NCCLCHECK(xmlGetAttr(sub, "target", &busId));
char* path;
NCCLCHECK(getPciPath(busId, &path));
NCCLCHECK(ncclTopoSetAttrFromSys(sub, path, "class", "tclass"));
}
}
*gpuNodeRet = gpuNode;
return ncclSuccess;
}
ncclResult_t ncclTopoFillGpu(struct ncclXml* xml, const char* busId, struct ncclXmlNode** gpuNode) {
struct ncclXmlNode* node;
NCCLCHECK(ncclTopoGetPciNode(xml, busId, &node));
NCCLCHECK(ncclTopoGetXmlFromSys(node, xml));
NCCLCHECK(wrapNvmlSymbols());
NCCLCHECK(wrapNvmlInit());
nvmlDevice_t nvmlDev;
if (wrapNvmlDeviceGetHandleByPciBusId(busId, &nvmlDev) != ncclSuccess) nvmlDev = NULL;
NCCLCHECK(ncclTopoGetXmlFromGpu(node, nvmlDev, xml, gpuNode));
return ncclSuccess;
}
// Returns the subsystem name of a path, i.e. the end of the path
// where sysPath/subsystem points to.
ncclResult_t ncclTopoGetSubsystem(const char* sysPath, char* subSys) {
char subSysPath[PATH_MAX];
sprintf(subSysPath, "%s/subsystem", sysPath);
char* path = realpath(subSysPath, NULL);
if (path == NULL) {
subSys[0] = '\0';
} else {
int offset;
for (offset = strlen(path); offset > 0 && path[offset] != '/'; offset--);
strcpy(subSys, path+offset+1);
free(path);
}
return ncclSuccess;
}
ncclResult_t ncclTopoFillNet(struct ncclXml* xml, const char* pciPath, const char* netName, struct ncclXmlNode** netNode) {
NCCLCHECK(xmlFindTagKv(xml, "net", netNode, "name", netName));
if (*netNode != NULL) return ncclSuccess;
const char* pciSysPath = pciPath;
if (pciSysPath) {
char subSystem[PATH_MAX];
NCCLCHECK(ncclTopoGetSubsystem(pciSysPath, subSystem));
// This is not a PCI device (virtual, usb, ...).
if (strcmp(subSystem, "pci") != 0) {
INFO(NCCL_GRAPH, "Topology detection: network path %s is not a PCI device (%s). Attaching to first CPU", pciSysPath, subSystem);
pciSysPath = NULL;
}
}
struct ncclXmlNode* parent = NULL;
if (pciSysPath) {
int offset;
for (offset=strlen(pciSysPath)-1; pciSysPath[offset] != '/'; offset--);
char busId[NVML_DEVICE_PCI_BUS_ID_BUFFER_SIZE];
strcpy(busId, pciSysPath+offset+1);
NCCLCHECK(xmlFindTagKv(xml, "pci", &parent, "busid", busId));
if (parent == NULL) {
NCCLCHECK(xmlAddNode(xml, NULL, "pci", &parent));
NCCLCHECK(xmlSetAttr(parent, "busid", busId));
NCCLCHECK(ncclTopoGetXmlFromSys(parent, xml));
}
} else {
// Virtual NIC, no PCI device, attach to first CPU
NCCLCHECK(xmlFindTag(xml, "cpu", &parent));
}
struct ncclXmlNode* nicNode = NULL;
NCCLCHECK(xmlGetSub(parent, "nic", &nicNode));
if (nicNode == NULL) {
NCCLCHECK(xmlAddNode(xml, parent, "nic", &nicNode));
}
// We know that this net does not exist yet (we searched for it at the
// beginning of this function), so we can add it.
NCCLCHECK(xmlAddNode(xml, nicNode, "net", netNode));
NCCLCHECK(xmlSetAttr(*netNode, "name", netName));
return ncclSuccess;
}
/**************************************************/
/* Parser rules for the user-defined graph search */
/**************************************************/
ncclResult_t ncclTopoXmlGraphLoadGpu(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head) {
NCCLCHECK(xmlLoadSub(file, xml, head, NULL, 0));
return ncclSuccess;
}
ncclResult_t ncclTopoXmlGraphLoadNet(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head) {
NCCLCHECK(xmlLoadSub(file, xml, head, NULL, 0));
return ncclSuccess;
}
ncclResult_t ncclTopoXmlGraphLoadChannel(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head) {
struct xmlHandler handlers[] = { { "net", ncclTopoXmlGraphLoadNet }, { "gpu", ncclTopoXmlGraphLoadGpu } };
NCCLCHECK(xmlLoadSub(file, xml, head, handlers, 2));
return ncclSuccess;
}
ncclResult_t ncclTopoXmlGraphLoadGraph(FILE* file, struct ncclXml* xml, struct ncclXmlNode* head) {
struct xmlHandler handlers[] = { { "channel", ncclTopoXmlGraphLoadChannel } };
NCCLCHECK(xmlLoadSub(file, xml, head, handlers, 1));
return ncclSuccess;
}
ncclResult_t ncclTopoXmlGraphLoadGraphs(FILE* file, struct ncclXml* xmlGraph, struct ncclXmlNode* head) {
int version;
NCCLCHECK(xmlGetAttrInt(head, "version", &version));
if (version != NCCL_GRAPH_XML_VERSION) {
WARN("XML Graph has wrong version %d, %d needed", version, NCCL_GRAPH_XML_VERSION);
return ncclInvalidUsage;
}
const char* name;
NCCLCHECK(xmlGetAttr(head, "name", &name));
if (name != NULL) INFO(NCCL_GRAPH, "Loading graphs for topology %s", name);
else INFO(NCCL_GRAPH, "Loading graphs");
struct xmlHandler handlers[] = { { "graph", ncclTopoXmlGraphLoadGraph } };
NCCLCHECK(xmlLoadSub(file, xmlGraph, head, handlers, 1));
return ncclSuccess;
}
ncclResult_t ncclTopoGetXmlGraphFromFile(const char* xmlGraphFile, struct ncclXml* xml) {
FILE* file = fopen(xmlGraphFile, "r");
if (file == NULL) {
WARN("Could not open XML graph file %s : %s", xmlGraphFile, strerror(errno));
return ncclSystemError;
}
struct xmlHandler handlers[] = { { "graphs", ncclTopoXmlGraphLoadGraphs } };
xml->maxIndex = 0;
NCCLCHECK(xmlLoadSub(file, xml, NULL, handlers, 1));
fclose(file);
return ncclSuccess;
}
src/graph/xml.h
+237
Visa fil
@@ -0,0 +1,237 @@
/*************************************************************************
* Copyright (c) 2019-2020, NVIDIA CORPORATION. All rights reserved.
*
* See LICENSE.txt for license information
************************************************************************/
#ifndef XML_H_
#define XML_H_
// A few constraints to make the implementation easy
#define MAX_STR_LEN 256
#define MAX_ATTR_COUNT 16
#define MAX_SUBS 32
#define MAX_NODES 1024
#define NODE_TYPE_NONE 0
#define NODE_TYPE_OPEN 1
#define NODE_TYPE_CLOSE 2
#define NODE_TYPE_SINGLE 3
struct ncclXmlNode {
char name[MAX_STR_LEN];
struct {
char key[MAX_STR_LEN];
char value[MAX_STR_LEN];
} attrs[MAX_ATTR_COUNT+1]; // Need an extra one to consume extra params
int nAttrs;
int type;
struct ncclXmlNode* parent;
struct ncclXmlNode* subs[MAX_SUBS];
int nSubs;
};
struct ncclXml {
struct ncclXmlNode nodes[MAX_NODES];
int maxIndex;
};
/* File functions */
#define NCCL_TOPO_XML_VERSION 1
ncclResult_t ncclTopoGetXmlFromFile(const char* xmlTopoFile, struct ncclXml* xml);
ncclResult_t ncclTopoDumpXmlToFile(const char* xmlTopoFile, struct ncclXml* xml);
#define NCCL_GRAPH_XML_VERSION 1
ncclResult_t ncclTopoGetXmlGraphFromFile(const char* xmlGraphFile, struct ncclXml* xml);
/* Auto-detect functions */
ncclResult_t ncclTopoFillGpu(struct ncclXml* xml, const char* busId, struct ncclXmlNode** gpuNode);
ncclResult_t ncclTopoFillNet(struct ncclXml* xml, const char* pciPath, const char* netName, struct ncclXmlNode** netNode);
/**************/
/* XML Struct */
/* Functions */
/**************/
static ncclResult_t xmlGetAttrIndex(struct ncclXmlNode* node, const char* attrName, int* index) {
*index = -1;
const int nAttrs = node->nAttrs;
for (int a=0; a<nAttrs; a++) {
if (strncmp(node->attrs[a].key, attrName, MAX_STR_LEN-1) == 0) {
*index = a;
return ncclSuccess;
}
}
return ncclSuccess;
}
static ncclResult_t xmlGetAttr(struct ncclXmlNode* node, const char* attrName, const char** value) {
int index;
NCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
*value = index == -1 ? NULL : node->attrs[index].value;
return ncclSuccess;
}
static ncclResult_t xmlGetAttrStr(struct ncclXmlNode* node, const char* attrName, const char** value) {
NCCLCHECK(xmlGetAttr(node, attrName, value));
if (*value == NULL) {
WARN("Attribute %s of node %s not found", attrName, node->name);
return ncclInternalError;
}
return ncclSuccess;
}
static ncclResult_t xmlGetAttrInt(struct ncclXmlNode* node, const char* attrName, int* value) {
const char* str;
NCCLCHECK(xmlGetAttrStr(node, attrName, &str));
*value = strtol(str, NULL, 0);
return ncclSuccess;
}
static ncclResult_t xmlGetAttrFloat(struct ncclXmlNode* node, const char* attrName, float* value) {
const char* str;
NCCLCHECK(xmlGetAttrStr(node, attrName, &str));
*value = strtof(str, NULL);
return ncclSuccess;
}
static ncclResult_t xmlFindTag(struct ncclXml* xml, const char* tagName, struct ncclXmlNode** node) {
*node = NULL;
for (int i=0; i<xml->maxIndex; i++) {
struct ncclXmlNode* n = xml->nodes+i;
if (strcmp(n->name, tagName) == 0) {
*node = n;
return ncclSuccess;
}
}
return ncclSuccess;
}
static ncclResult_t xmlFindTagKv(struct ncclXml* xml, const char* tagName, struct ncclXmlNode** node, const char* attrName, const char* attrValue) {
*node = NULL;
for (int i=0; i<xml->maxIndex; i++) {
struct ncclXmlNode* n = xml->nodes+i;
if (strcmp(n->name, tagName) == 0) {
const char* value;
NCCLCHECK(xmlGetAttr(n, attrName, &value));
if (value && strcmp(value, attrValue) == 0) {
*node = n;
return ncclSuccess;
}
}
}
return ncclSuccess;
}
static ncclResult_t xmlSetAttr(struct ncclXmlNode* node, const char* attrName, const char* value) {
int index;
NCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
if (index == -1) {
index = node->nAttrs++;
strncpy(node->attrs[index].key, attrName, MAX_STR_LEN);
}
strncpy(node->attrs[index].value, value, MAX_STR_LEN);
return ncclSuccess;
}
static ncclResult_t xmlSetAttrInt(struct ncclXmlNode* node, const char* attrName, const int value) {
int index;
NCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
if (index == -1) {
index = node->nAttrs++;
strncpy(node->attrs[index].key, attrName, MAX_STR_LEN);
}
snprintf(node->attrs[index].value, MAX_STR_LEN, "%d", value);
return ncclSuccess;
}
static ncclResult_t xmlSetAttrFloat(struct ncclXmlNode* node, const char* attrName, const float value) {
int index;
NCCLCHECK(xmlGetAttrIndex(node, attrName, &index));
if (index == -1) {
index = node->nAttrs++;
strncpy(node->attrs[index].key, attrName, MAX_STR_LEN);
}
snprintf(node->attrs[index].value, MAX_STR_LEN, "%g", value);
return ncclSuccess;
}
static ncclResult_t xmlGetSub(struct ncclXmlNode* node, const char* subName, struct ncclXmlNode** sub) {
*sub = NULL;
for (int s=0; s<node->nSubs; s++) {
if (strcmp(node->subs[s]->name, subName) == 0) {
*sub = node->subs[s];
return ncclSuccess;
}
}
return ncclSuccess;
}
static ncclResult_t xmlGetSubKv(struct ncclXmlNode* node, const char* subName, struct ncclXmlNode** sub, const char* attrName, const char* attrValue) {
*sub = NULL;
for (int s=0; s<node->nSubs; s++) {
struct ncclXmlNode* subNode = node->subs[s];
if (strcmp(subNode->name, subName) == 0) {
const char* value;
NCCLCHECK(xmlGetAttr(subNode, attrName, &value));
if (value && strcmp(value, attrValue) == 0) {
*sub = node->subs[s];
return ncclSuccess;
}
}
}
return ncclSuccess;
}
static ncclResult_t xmlGetSubKvInt(struct ncclXmlNode* node, const char* subName, struct ncclXmlNode** sub, const char* attrName, const int attrValue) {
char strValue[10];
snprintf(strValue, 10, "%d", attrValue);
NCCLCHECK(xmlGetSubKv(node, subName, sub, attrName, strValue));
return ncclSuccess;
}
static ncclResult_t xmlAddNode(struct ncclXml* xml, struct ncclXmlNode* parent, const char* subName, struct ncclXmlNode** sub) {
if (xml->maxIndex == MAX_NODES) {
WARN("Error : too many XML nodes (max %d)", MAX_NODES);
return ncclInternalError;
}
struct ncclXmlNode* s = xml->nodes+xml->maxIndex++;
s->nSubs = 0;
s->nAttrs = 0;
*sub = s;
s->parent = parent;
if (parent) parent->subs[parent->nSubs++] = s;
strncpy(s->name, subName, MAX_STR_LEN);
return ncclSuccess;
}
// Dictionary for STR -> INT conversions. No dictionary size information,
// there needs to be a last element with str == NULL.
struct kvDict {
const char* str;
int value;
};
static ncclResult_t kvConvertToInt(const char* str, int* value, struct kvDict* dict) {
struct kvDict* d = dict;
while (d->str) {
if (strncmp(str, d->str, strlen(d->str)) == 0) {
*value = d->value;
return ncclSuccess;
}
d++;
}
WARN("KV Convert to int : could not find value of '%s' in dictionary", str);
return ncclInternalError;
}
static ncclResult_t kvConvertToStr(int value, const char** str, struct kvDict* dict) {
struct kvDict* d = dict;
while (d->str) {
if (value == d->value) {
*str = d->str;
return ncclSuccess;
}
d++;
}
WARN("KV Convert to str : could not find value %d in dictionary", value);
return ncclInternalError;
}
#endif