doubling debug buffer size with increased channels

tools/topo_expl/utils.cpp

@@ -1089,7 +1089,7 @@ ncclResult_t initTransportsRank_3(struct ncclComm* comm, struct allGatherInfo *a
 
   TRACE(NCCL_INIT, "rank %d nranks %d - BUILT %d TREES/RINGS", rank, nranks, comm->nChannels);
 
-  char line[2048];
+  char line[4096];
   line[0]='\0';
   for (int c=0; c<comm->nChannels; c++) {
     struct ncclTree* tree = &comm->channels[c].tree;
@@ -1098,7 +1098,7 @@ ncclResult_t initTransportsRank_3(struct ncclComm* comm, struct allGatherInfo *a
     INFO(NCCL_GRAPH, "Ring %d : %d -> %d -> %d comm %p nRanks %02d busId %lx", c, comm->channels[c].ring.prev,
          comm->rank, comm->channels[c].ring.next, comm, comm->nRanks, comm->busId);
   }
-  line[2047] = '\0';
+  line[4095] = '\0';
   INFO(NCCL_INIT, "Trees%s comm %p nRanks %02d busId %lx", line, comm, comm->nRanks, comm->busId);
 
   //NCCLCHECKGOTO(computeBuffSizes(comm), ret, fail);