diff --git a/[refs] b/[refs]
index 8c6f92b68f5e..19e45e5be26a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 44ee63587dce85593c22497140db16f4e5027860
+refs/heads/master: 84c6f88fc8265d7a712d7d6ed8fc1a878dfc84d1
diff --git a/trunk/lib/Kconfig.debug b/trunk/lib/Kconfig.debug
index 25c3ed594c54..65f964e7fe78 100644
--- a/trunk/lib/Kconfig.debug
+++ b/trunk/lib/Kconfig.debug
@@ -520,6 +520,12 @@ config LOCK_STAT
 
 	 For more details, see Documentation/lockstat.txt
 
+	 You can analyze lock events with "perf lock", subcommand of perf.
+	 If you want to use "perf lock", you need to turn on CONFIG_EVENT_TRACING.
+
+	 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
+ 	 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
+
 config DEBUG_LOCKDEP
 	bool "Lock dependency engine debugging"
 	depends on DEBUG_KERNEL && LOCKDEP
diff --git a/trunk/tools/perf/Documentation/perf-lock.txt b/trunk/tools/perf/Documentation/perf-lock.txt
new file mode 100644
index 000000000000..b317102138c8
--- /dev/null
+++ b/trunk/tools/perf/Documentation/perf-lock.txt
@@ -0,0 +1,29 @@
+perf-lock(1)
+============
+
+NAME
+----
+perf-lock - Analyze lock events
+
+SYNOPSIS
+--------
+[verse]
+'perf lock' {record|report|trace}
+
+DESCRIPTION
+-----------
+You can analyze various lock behaviours
+and statistics with this 'perf lock' command.
+
+  'perf lock record <command>' records lock events
+  between start and end <command>. And this command
+  produces the file "perf.data" which contains tracing
+  results of lock events.
+
+  'perf lock trace' shows raw lock events.
+
+  'perf lock report' reports statistical data.
+
+SEE ALSO
+--------
+linkperf:perf[1]
diff --git a/trunk/tools/perf/command-list.txt b/trunk/tools/perf/command-list.txt
index 9afcff2e3ae5..db6ee94d4a8e 100644
--- a/trunk/tools/perf/command-list.txt
+++ b/trunk/tools/perf/command-list.txt
@@ -18,3 +18,4 @@ perf-top			mainporcelain common
 perf-trace			mainporcelain common
 perf-probe			mainporcelain common
 perf-kmem			mainporcelain common
+perf-lock			mainporcelain common