diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 3b304ed4d2e9e44b93c9668bc0441677cdb1792e..d7dde9cbbdf4c902943c6932a097356063cd8bd1 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -733,8 +733,8 @@ static void print_bad_events(int bad, int total)
 		{ "acquire", "acquired", "contended", "release" };
 
 	pr_info("\n=== output for debug===\n\n");
-	pr_info("bad:%d, total:%d\n", bad, total);
-	pr_info("bad rate:%f\n", (double)(bad / total));
+	pr_info("bad: %d, total: %d\n", bad, total);
+	pr_info("bad rate: %f %%\n", (double)bad / (double)total * 100);
 	pr_info("histogram of events caused bad sequence\n");
 	for (i = 0; i < BROKEN_MAX; i++)
 		pr_info(" %10s: %d\n", name[i], bad_hist[i]);