AI/rocm-systems
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Cód Saincheisteanna Iarratais Tarraingthe Gníomhartha Pacáistí Tionscadail Scaoileann Vicí Gníomhaíocht

Revert "Changes to topology based on XGMI (#272)"

Brabhsáil Foinse 
This reverts commit 0a9adc16f4.


[ROCm/rccl commit: e055229e56]
Tá an tiomantas seo le fáil i:
Wenkai Du
2020-12-08 16:51:34 -05:00
tuismitheoir adff98765c
tiomantas 34c6013299
D'athraigh 3 comhad le 35 breiseanna agus 122 scriosta
Íoslódáil an comhad paiste Íoslódáil Comhad Diff Leathnaigh gach comhaid Laghdaigh gach comhaid
projects/rccl/src/graph/paths.cc
+1 -90
Féach ar an gComhad
@@ -30,84 +30,6 @@ static ncclResult_t getPath(struct ncclTopoSystem* system, struct ncclTopoNode*
return ncclInternalError;
}
// [RCCL]
// This function traverses only XGMI links (including multi-GPU hops) and builds them into the
// topology system, which corresponds to how XGMI hardware operates
static ncclResult_t ncclTopoSetXgmi(struct ncclTopoSystem* system)
{
// Compute paths to GPU g
for (int g=0; g<system->nodes[GPU].count; g++) {
struct ncclTopoNode *baseNode = system->nodes[GPU].nodes+g;
if (baseNode->paths[baseNode->type] == NULL) {
NCCLCHECK(ncclCalloc(baseNode->paths+baseNode->type, system->nodes[baseNode->type].count));
}
// breadth-first search to set all paths to that node in the system
struct ncclTopoNodeList nodeList;
struct ncclTopoNodeList nextNodeList;
nodeList.count = 1; nodeList.list[0] = baseNode;
nextNodeList.count = 0;
struct ncclTopoLinkList* basePath;
NCCLCHECK(getPath(system, baseNode, baseNode->type, baseNode->id, &basePath));
basePath->count = 0;
basePath->width = LOC_WIDTH;
basePath->type = PATH_LOC;
while (nodeList.count) {
nextNodeList.count = 0;
for (int n=0; n<nodeList.count; n++) {
struct ncclTopoNode* node = nodeList.list[n];
struct ncclTopoLinkList* path;
NCCLCHECK(getPath(system, node, baseNode->type, baseNode->id, &path));
for (int l=0; l<node->nlinks; l++) {
struct ncclTopoLink* link = node->links+l;
struct ncclTopoNode* remNode = link->remNode;
// Skip non-XGMI links
if (link->type != LINK_NVL) continue;
if (remNode->paths[baseNode->type] == NULL) {
NCCLCHECK(ncclCalloc(remNode->paths+baseNode->type, system->nodes[baseNode->type].count));
}
struct ncclTopoLinkList* remPath;
NCCLCHECK(getPath(system, remNode, baseNode->type, baseNode->id, &remPath));
float width = std::min(path->width, link->width);
if (remPath->width < width) {
// Find reverse link
for (int l=0; l<remNode->nlinks; l++) {
if (remNode->links[l].remNode == node) {
remPath->list[0] = remNode->links+l;
break;
}
}
if (remPath->list[0] == NULL) {
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
for (int i=0; i<path->count; i++) remPath->list[i+1] = path->list[i];
remPath->count = path->count + 1;
remPath->width = width;
remPath->type = PATH_NVL;
// Add to the list for the next iteration if not already in the list
// In this case, permit GPUs are intermediate XGMI steps
for (int i=0; i<nextNodeList.count; i++) if (nextNodeList.list[i] == remNode) continue;
nextNodeList.list[nextNodeList.count++] = remNode;
}
}
}
memcpy(&nodeList, &nextNodeList, sizeof(nodeList));
}
}
return ncclSuccess;
}
// [/RCCL]
static ncclResult_t ncclTopoSetPaths(struct ncclTopoNode* baseNode, struct ncclTopoSystem* system) {
if (baseNode->paths[baseNode->type] == NULL) {
NCCLCHECK(ncclCalloc(baseNode->paths+baseNode->type, system->nodes[baseNode->type].count));
@@ -139,14 +61,7 @@ static ncclResult_t ncclTopoSetPaths(struct ncclTopoNode* baseNode, struct ncclT
struct ncclTopoLinkList* remPath;
NCCLCHECK(getPath(system, remNode, baseNode->type, baseNode->id, &remPath));
float width = std::min(path->width, link->width);
// [RCCL] Do not let XGMI paths be overwritten (even if PCIe path may be faster)
// Unless they are of shorter length
// if (remPath->width < width) {
bool notXGMI = remPath->type != PATH_NVL;
if (remPath->width < width && notXGMI) {
// [/RCCL]
if (remPath->width < width) {
// Find reverse link
for (int l=0; l<remNode->nlinks; l++) {
if (remNode->links[l].remNode == node) {
@@ -451,10 +366,6 @@ ncclResult_t ncclTopoComputePaths(struct ncclTopoSystem* system, struct ncclPeer
NCCLCHECK(ncclTopoSetPaths(system->nodes[CPU].nodes+c, system));
}
// [RCCL] Add XGMI-only links between GPUs first before any other paths
NCCLCHECK(ncclTopoSetXgmi(system));
// [/RCCL]
// Set direct paths from/to GPUs.
for (int g=0; g<system->nodes[GPU].count; g++) {
// Compute paths to GPU g