From fa6d7e9a63038ba13208ef8dc34b5882d4423118 Mon Sep 17 00:00:00 2001
From: Wenkai Du <43822138+wenkaidu@users.noreply.github.com>
Date: Tue, 22 Jun 2021 08:41:49 -0700
Subject: [PATCH] Fixes for NCCL_MAX_NCHANNELS and topo_expl (#398)

---
 src/graph/connect.cc      | 1 +
 tools/topo_expl/utils.cpp | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/graph/connect.cc b/src/graph/connect.cc
index 5dbc0ad753..4ea634483e 100644
--- a/src/graph/connect.cc
+++ b/src/graph/connect.cc
@@ -292,6 +292,7 @@ ncclResult_t ncclTopoPostset(struct ncclComm* comm, int* firstRanks, int* treePa
 
   // Get number of channels after duplication
   nc *= comm->nChannels;
+  nc = std::min((int)ncclMaxNchannels(), nc);
   // Duplication should be complete now
   nChannels = comm->nChannels = std::min(MAXCHANNELS,nChannels*2);
 
diff --git a/tools/topo_expl/utils.cpp b/tools/topo_expl/utils.cpp
index 7610963815..269d642092 100644
--- a/tools/topo_expl/utils.cpp
+++ b/tools/topo_expl/utils.cpp
@@ -404,7 +404,7 @@ ncclResult_t initTransportsRank_1(struct ncclComm* comm, struct allGather1Data_t
 
   if ((comm->topo->type & RCCL_TOPO_4P2H_ROME) && (comm->topo->type & RCCL_TOPO_GDR_ALL)) {
     if (rcclParamP2pNetDisable() == 0) {
-      STORE(comm->p2pNet, 1);
+      comm->p2pNet = 1;
       INFO(NCCL_INIT, "RCCL enabled same node P2P over network");
     }
     else