Thread (139 messages) 139 messages, 10 authors, 2021-05-25
STALE1889d

[PATCH 5.12 032/127] locking/lockdep: Correct calling tracepoints

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-05-24 16:04:26
Also in: lkml
Subsystem: locking primitives, the rest · Maintainers: Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, Linus Torvalds

From: Leo Yan <redacted>

[ Upstream commit 89e70d5c583c55088faa2201d397ee30a15704aa ]

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 <redacted>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210512120937.90211-1-leo.yan@linaro.org
Signed-off-by: Sasha Levin <sashal@kernel.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 f160f1c97ca1..f39c383c7180 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -5731,7 +5731,7 @@ 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;
@@ -5749,7 +5749,7 @@ 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;
-- 
2.30.2


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