Unit Tests for testing channels (#1222)

2024-06-25 10:10:10 -05:00
parent 5f2b88bc28
commit e170f41ddd
5 changed files with 53 additions and 38 deletions
@@ -674,7 +674,11 @@ ncclResult_t ncclTopoPostset(struct ncclComm* comm, int* firstRanks, int* treePa

  int minNchannels = ncclMinNchannels();
  if (comm->nNodes > 1) {
-    minNchannels = std::min(64, minNchannels);
+    minNchannels = std::min(64, maxChannels);
+  }
+  if (comm->nRanks < 8 && 64 < minNchannels) {
+    minNchannels = 2;
+    WARN("NCCL_MIN_NCHANNELS set by environment is ignored due to less than 8 GPUs.");
  }

  if (mscclEnabled() && (comm->topo->mscclEnabled || mscclForceEnabled())) {