Merge remote-tracking branch 'nccl/master' into develop

src/group.cc

@@ -213,8 +213,8 @@ static void groupCleanup(struct ncclComm** groupCommHeadPtr, struct ncclComm** g
     for (int i = 0; i < comm->nRanks; i++) {
       comm->tasks.peers[i].sendSeen = false;
       comm->tasks.peers[i].recvSeen = false;
-      comm->connectSend[i] = 0;
-      comm->connectRecv[i] = 0;
+      comm->connectSend[i] = 0UL;
+      comm->connectRecv[i] = 0UL;
     }
     comm->unlaunchedPlansHead = nullptr;
     // Reclaim abandoned kernel plan memory. Note ncclWork structs were already
@@ -333,6 +333,8 @@ static ncclResult_t groupLaunch(struct ncclAsyncJob *job_) {
 
         job = job->next;
       } while (job != nullptr);
+      // Let preconnect threads progress.
+      if (jobsDone == false) usleep(1);
     } while (jobsDone == false);
 
     if (ret != ncclSuccess) goto fail;