NCCL 2.26.3-1

Minimize the performance impact of the device kernel profiling support when
the profiler plugin is not loaded.

Reduce the overheads of CUDA graph capturing, which increased in NCCL
2.26.2 for large graphs.

Fix the exchange of enhanced connection establishment (ECE) options to
address potential slowdowns on networks utilizing RoCE.

Test if cuMem host allocations work and if not, disable them. Enabled by
default since NCCL 2.24 if the CUDA driver version is at least 12.6, such
allocations rely on NUMA support, which is by default not available under
Docker. We recommend invoking Docker with "--cap-add SYS_NICE" to enable
it.

Fix an initialization error when running with NCCL_NET_GDR_C2C=1 on
multiple MNNVL domains with non-uniform network configurations across
nodes.

Fix the printing of sub-seconds in the debug log when using a custom
NCCL_DEBUG_TIMESTAMP_FORMAT setting.

src/graph/paths.cc

@@ -367,7 +367,7 @@ ncclResult_t ncclTopoCheckMNNVL(struct ncclTopoSystem* system, struct ncclPeerIn
   if ((((long *)&fabricInfo2->clusterUuid)[0]|((long *)fabricInfo2->clusterUuid)[1]) == 0) return ncclSuccess;
   if ((memcmp(fabricInfo1->clusterUuid, fabricInfo2->clusterUuid, NVML_GPU_FABRIC_UUID_LEN) == 0) &&
       (fabricInfo1->cliqueId == fabricInfo2->cliqueId)) {
-    INFO(NCCL_NET, "MNNVL matching peer 0x%lx UUID %lx.%lx cliqueId 0x%x",
+    TRACE(NCCL_NET, "MNNVL matching peer 0x%lx UUID %lx.%lx cliqueId 0x%x",
          info2->busId, ((long *)fabricInfo2->clusterUuid)[0], ((long *)fabricInfo2->clusterUuid)[1], fabricInfo2->cliqueId);
     *ret = 1;
   }
@@ -473,7 +473,7 @@ ncclResult_t ncclTopoIsGdrAvail(struct ncclTopoSystem* system, int rank, bool *a
 NCCL_PARAM(NetForceFlush, "NET_FORCE_FLUSH", 0);
 
 // Determine whether we need to flush the GDR recv buffers
-ncclResult_t ncclTopoNeedFlush(struct ncclComm* comm, int netDev, int rank, int* flush) {
+ncclResult_t ncclTopoNeedFlush(struct ncclComm* comm, int64_t netId, int netDev, int rank, int* flush) {
   *flush = 1;
   ncclNetProperties_t props;
   NCCLCHECK(comm->ncclNet->getProperties(netDev, &props));
@@ -488,7 +488,7 @@ ncclResult_t ncclTopoNeedFlush(struct ncclComm* comm, int netDev, int rank, int*
   // flags would go through C2C. In that case, force a flush.
   int c, n;
   NCCLCHECK(ncclGetLocalCpu(system, g, &c));
-  NCCLCHECK(ncclTopoIdToIndex(system, NET, netDev, &n));
+  NCCLCHECK(ncclTopoIdToIndex(system, NET, netId, &n));
   if (gpu->paths[NET][n].type <= PATH_PXB && gpu->paths[CPU][c].type == PATH_C2C) {
     *flush = 1;
   }