Commit 1a616c2f authored by Kent Overstreet's avatar Kent Overstreet
Browse files

lockdep: lockdep_set_notrack_class() 



Add a new helper to disable lockdep tracking entirely for a given class.

This is needed for bcachefs, which takes too many btree node locks for
lockdep to track. Instead, we have a single lockdep_map for "btree_trans
has any btree nodes locked", which makes more since given that we have
centralized lock management and a cycle detector.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 8f523d42

fs/bcachefs/btree_locking.c

+1 −1
Original line number Diff line number Diff line
@@ -10,7 +10,7 @@ void bch2_btree_lock_init(struct btree_bkey_cached_common *b, 
			  enum six_lock_init_flags flags)

{

	__six_lock_init(&b->lock, "b->c.lock", &bch2_btree_node_lock_key, flags);

	lockdep_set_novalidate_class(&b->lock);

	lockdep_set_notrack_class(&b->lock);

}



#ifdef CONFIG_LOCKDEP

include/linux/lockdep.h

+4 −0
Original line number Diff line number Diff line
@@ -181,6 +181,9 @@ static inline void lockdep_init_map(struct lockdep_map *lock, const char *name, 
#define lockdep_set_novalidate_class(lock) \

	lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)



#define lockdep_set_notrack_class(lock) \

	lockdep_set_class_and_name(lock, &__lockdep_no_track__, #lock)



/*

 * Compare locking classes

 */
@@ -338,6 +341,7 @@ static inline void lockdep_set_selftest_task(struct task_struct *task) 
#define lockdep_set_subclass(lock, sub)		do { } while (0)



#define lockdep_set_novalidate_class(lock) do { } while (0)

#define lockdep_set_notrack_class(lock) do { } while (0)



/*

 * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP

include/linux/lockdep_types.h

+1 −0
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ struct lock_class_key { 
};



extern struct lock_class_key __lockdep_no_validate__;

extern struct lock_class_key __lockdep_no_track__;



struct lock_trace;

kernel/locking/lockdep.c

+8 −1
Original line number Diff line number Diff line
@@ -4918,6 +4918,9 @@ EXPORT_SYMBOL_GPL(lockdep_init_map_type); 
struct lock_class_key __lockdep_no_validate__;

EXPORT_SYMBOL_GPL(__lockdep_no_validate__);



struct lock_class_key __lockdep_no_track__;

EXPORT_SYMBOL_GPL(__lockdep_no_track__);



#ifdef CONFIG_PROVE_LOCKING

void lockdep_set_lock_cmp_fn(struct lockdep_map *lock, lock_cmp_fn cmp_fn,

			     lock_print_fn print_fn)
@@ -5002,6 +5005,9 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, 
	if (unlikely(!debug_locks))

		return 0;



	if (unlikely(lock->key == &__lockdep_no_track__))

		return 0;



	if (!prove_locking || lock->key == &__lockdep_no_validate__)

		check = 0;
@@ -5764,7 +5770,8 @@ void lock_release(struct lockdep_map *lock, unsigned long ip) 


	trace_lock_release(lock, ip);



	if (unlikely(!lockdep_enabled()))

	if (unlikely(!lockdep_enabled() ||

		     lock->key == &__lockdep_no_track__))

		return;



	raw_local_irq_save(flags);