[tip: locking/core] locking/lock_events: Add locking events for lockdep

[tip-bot2 for Waiman Long]

The following commit has been merged into the locking/core branch of tip:

Commit-ID:     a94d32446ab5e85c7ba97e48a8c9bd85be4fe889
Gitweb:        https://git.kernel.org/tip/a94d32446ab5e85c7ba97e48a8c9bd85be4fe889
Author:        Waiman Long <longman@xxxxxxxxxx>
AuthorDate:    Fri, 07 Mar 2025 15:26:54 -08:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Sat, 08 Mar 2025 00:55:03 +01:00

locking/lock_events: Add locking events for lockdep

Add some lock events to lockdep to profile its behavior.

Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20250307232717.1759087-5-boqun.feng@xxxxxxxxx
---
 kernel/locking/lock_events_list.h | 7 +++++++
 kernel/locking/lockdep.c          | 8 +++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/kernel/locking/lock_events_list.h b/kernel/locking/lock_events_list.h
index 80b11f1..9ef9850 100644
--- a/kernel/locking/lock_events_list.h
+++ b/kernel/locking/lock_events_list.h
@@ -88,3 +88,10 @@ LOCK_EVENT(rtmutex_slow_acq3)	/* # of locks acquired in *block()	*/
 LOCK_EVENT(rtmutex_slow_sleep)	/* # of sleeps				*/
 LOCK_EVENT(rtmutex_slow_wake)	/* # of wakeup's			*/
 LOCK_EVENT(rtmutex_deadlock)	/* # of rt_mutex_handle_deadlock()'s	*/
+
+/*
+ * Locking events for lockdep
+ */
+LOCK_EVENT(lockdep_acquire)
+LOCK_EVENT(lockdep_lock)
+LOCK_EVENT(lockdep_nocheck)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 4470680..8436f01 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -61,6 +61,7 @@
 #include <asm/sections.h>
 
 #include "lockdep_internals.h"
+#include "lock_events.h"
 
 #include <trace/events/lock.h>
 
@@ -170,6 +171,7 @@ static struct task_struct *lockdep_selftest_task_struct;
 static int graph_lock(void)
 {
 	lockdep_lock();
+	lockevent_inc(lockdep_lock);
 	/*
 	 * Make sure that if another CPU detected a bug while
 	 * walking the graph we dont change it (while the other
@@ -5091,8 +5093,12 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 	if (unlikely(lock->key == &__lockdep_no_track__))
 		return 0;
 
-	if (!prove_locking || lock->key == &__lockdep_no_validate__)
+	lockevent_inc(lockdep_acquire);
+
+	if (!prove_locking || lock->key == &__lockdep_no_validate__) {
 		check = 0;
+		lockevent_inc(lockdep_nocheck);
+	}
 
 	if (subclass < NR_LOCKDEP_CACHING_CLASSES)
 		class = lock->class_cache[subclass];