From b8efb56172bc55082b8490778b07ef73eea0b551 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Mon, 15 Oct 2007 17:00:10 +0200
Subject: sched debug: BKL usage statistics

add per task and per rq BKL usage statistics.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/sched.c | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'kernel/sched.c')

diff --git a/kernel/sched.c b/kernel/sched.c
index f33608e9e1a2..5004dff91850 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -356,6 +356,9 @@ struct rq {
 	/* try_to_wake_up() stats */
 	unsigned long ttwu_cnt;
 	unsigned long ttwu_local;
+
+	/* BKL stats */
+	unsigned long bkl_cnt;
 #endif
 	struct lock_class_key rq_lock_key;
 };
@@ -3414,6 +3417,12 @@ static inline void schedule_debug(struct task_struct *prev)
 	profile_hit(SCHED_PROFILING, __builtin_return_address(0));
 
 	schedstat_inc(this_rq(), sched_cnt);
+#ifdef CONFIG_SCHEDSTATS
+	if (unlikely(prev->lock_depth >= 0)) {
+		schedstat_inc(this_rq(), bkl_cnt);
+		schedstat_inc(prev, sched_info.bkl_cnt);
+	}
+#endif
 }
 
 /*
-- 
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