plot_model.py: fix run on machine with one socket/NUMA node

python/plot_model.py

@@ -39,6 +39,8 @@ print(f"{topo.nb_cores_total} cores")
 nb_cores_to_consider = topo.nb_cores_per_numa_node * topo.nb_numa_nodes_per_socket
 if not cli_args.only_first_socket:
     nb_cores_to_consider *= topo.nb_sockets
+if topo.nb_numa_nodes_total == 1 or not cli_args.only_first_socket:
+    nb_cores_to_consider -= 1  # one core is used by communication thread
 print(f"Will consider the performance with up to {nb_cores_to_consider} cores")
 
 
@@ -52,10 +54,11 @@ if cli_args.model:
     model_local.print_params()
 
 
-    print("** Modeling remote accesses...")
+    if topo.nb_numa_nodes_total > 1:
+        print("** Modeling remote accesses...")
 
-    model_remote = get_model(cli_args.comp_kernel, topo.nb_numa_nodes_per_socket, nb_cores_to_consider)
-    model_remote.print_params()
+        model_remote = get_model(cli_args.comp_kernel, topo.nb_numa_nodes_per_socket, nb_cores_to_consider)
+        model_remote.print_params()
 else:
     print("** Skipping model building")