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From:   Leo Yan <leo.yan@linaro.org>
To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
        Waiman Long <longman@redhat.com>,
        Boqun Feng <boqun.feng@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        "Steven Rostedt (VMware)" <rostedt@goodmis.org>,
        linux-kernel@vger.kernel.org
Cc:     Leo Yan <leo.yan@linaro.org>
Subject: [PATCH] locking/lockdep: Correct calling tracepoints
Date:   Wed, 12 May 2021 20:09:37 +0800
Message-Id: <20210512120937.90211-1-leo.yan@linaro.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The commit eb1f00237aca ("lockdep,trace: Expose tracepoints") reverses
tracepoints for lock_contended() and lock_acquired(), thus the ftrace
log shows the wrong locking sequence that "acquired" event is prior to
"contended" event:

  <idle>-0       [001] d.s3 20803.501685: lock_acquire: 0000000008b91ab4 &sg_policy->update_lock
  <idle>-0       [001] d.s3 20803.501686: lock_acquired: 0000000008b91ab4 &sg_policy->update_lock
  <idle>-0       [001] d.s3 20803.501689: lock_contended: 0000000008b91ab4 &sg_policy->update_lock
  <idle>-0       [001] d.s3 20803.501690: lock_release: 0000000008b91ab4 &sg_policy->update_lock

This patch fixes calling tracepoints for lock_contended() and
lock_acquired().

Fixes: eb1f00237aca ("lockdep,trace: Expose tracepoints")
Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 kernel/locking/lockdep.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 48d736aa03b2..7641bd407239 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -5736,7 +5736,7 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
 {
 	unsigned long flags;
 
-	trace_lock_acquired(lock, ip);
+	trace_lock_contended(lock, ip);
 
 	if (unlikely(!lock_stat || !lockdep_enabled()))
 		return;
@@ -5754,7 +5754,7 @@ void lock_acquired(struct lockdep_map *lock, unsigned long ip)
 {
 	unsigned long flags;
 
-	trace_lock_contended(lock, ip);
+	trace_lock_acquired(lock, ip);
 
 	if (unlikely(!lock_stat || !lockdep_enabled()))
 		return;
-- 
2.25.1