Enable collnet in RCCL (#333)

* Enable CollNet and use different number of channels

* topo_expl: enable collnet

tools/scripts/topo_val.sh

@@ -21,8 +21,13 @@
 
 DIR="$(cd -P "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
-for i in {0..49}
+for i in {0..50}
 do
-	$DIR/../topo_expl/topo_expl -m $i > "topo_m$i.log"
+	if [[ $i -eq 50 ]]
+	then
+		NCCL_COLLNET_ENABLE=1 $DIR/../topo_expl/topo_expl -m $i > "topo_m$i.log"
+	else
+		$DIR/../topo_expl/topo_expl -m $i > "topo_m$i.log"
+	fi
 	$DIR/../TopoVisual/topo_visual.sh -i "topo_m$i.log"
 done