perf mem: Introduce --list-cmds for use by scripts

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1394853474-31019-3-git-send-email-artagnon@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
diff --git a/tools/perf/builtin-mem.c b/tools/perf/builtin-mem.c
index 2e3ade69..4a1a6c9 100644
--- a/tools/perf/builtin-mem.c
+++ b/tools/perf/builtin-mem.c
@@ -21,11 +21,6 @@
 	DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
 };
 
-static const char * const mem_usage[] = {
-	"perf mem [<options>] {record <command> |report}",
-	NULL
-};
-
 static int __cmd_record(int argc, const char **argv)
 {
 	int rec_argc, i = 0, j;
@@ -220,9 +215,15 @@
 		   " between columns '.' is reserved."),
 	OPT_END()
 	};
+	const char *const mem_subcommands[] = { "record", "report", NULL };
+	const char *mem_usage[] = {
+		NULL,
+		NULL
+	};
 
-	argc = parse_options(argc, argv, mem_options, mem_usage,
-			     PARSE_OPT_STOP_AT_NON_OPTION);
+
+	argc = parse_options_subcommand(argc, argv, mem_options, mem_subcommands,
+					mem_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 
 	if (!argc || !(strncmp(argv[0], "rec", 3) || mem_operation))
 		usage_with_options(mem_usage, mem_options);