diff --git a/[refs] b/[refs]
index f65c12529e9d..49419caebcf8 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: dda7c02f33833bfa9412ba6f0e410b0a18b42c88
+refs/heads/master: af9522cf133e9be6da8525a46a9ed7e7659f0e1a
diff --git a/trunk/Documentation/perf_counter/kerneltop.c b/trunk/Documentation/perf_counter/kerneltop.c
index 0bd3c13150b1..81a68aac137f 100644
--- a/trunk/Documentation/perf_counter/kerneltop.c
+++ b/trunk/Documentation/perf_counter/kerneltop.c
@@ -387,6 +387,9 @@ int do_perfstat(int argc, char *argv[])
 	argc -= optind;
 	argv += optind;
 
+	if (!argc)
+		display_help();
+
 	/*
 	 * Enable counters and exec the command:
 	 */