Lockdep: add lockdep_set_class_and_subclass() and lockdep_set_subclass()
This annotation makes it possible to assign a subclass on lock init. This
annotation is meant to reduce the _nested() annotations by assigning a
default subclass.
One could do without this annotation and rely on lockdep_set_class()
exclusively, but that would require a manual stack of struct lock_class_key
objects.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 1314ca0..14fec2a 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -202,7 +202,7 @@
*/
extern void lockdep_init_map(struct lockdep_map *lock, const char *name,
- struct lock_class_key *key);
+ struct lock_class_key *key, int subclass);
/*
* Reinitialize a lock key - for cases where there is special locking or
@@ -211,9 +211,14 @@
* or they are too narrow (they suffer from a false class-split):
*/
#define lockdep_set_class(lock, key) \
- lockdep_init_map(&(lock)->dep_map, #key, key)
+ lockdep_init_map(&(lock)->dep_map, #key, key, 0)
#define lockdep_set_class_and_name(lock, key, name) \
- lockdep_init_map(&(lock)->dep_map, name, key)
+ lockdep_init_map(&(lock)->dep_map, name, key, 0)
+#define lockdep_set_class_and_subclass(lock, key, sub) \
+ lockdep_init_map(&(lock)->dep_map, #key, key, sub)
+#define lockdep_set_subclass(lock, sub) \
+ lockdep_init_map(&(lock)->dep_map, #lock, \
+ (lock)->dep_map.key, sub)
/*
* Acquire a lock.
@@ -257,10 +262,12 @@
# define lock_release(l, n, i) do { } while (0)
# define lockdep_init() do { } while (0)
# define lockdep_info() do { } while (0)
-# define lockdep_init_map(lock, name, key) do { (void)(key); } while (0)
+# define lockdep_init_map(lock, name, key, sub) do { (void)(key); } while (0)
# define lockdep_set_class(lock, key) do { (void)(key); } while (0)
# define lockdep_set_class_and_name(lock, key, name) \
do { (void)(key); } while (0)
+#define lockdep_set_class_and_subclass(lock, key, sub) \
+ do { (void)(key); } while (0)
# define INIT_LOCKDEP
# define lockdep_reset() do { debug_locks = 1; } while (0)
# define lockdep_free_key_range(start, size) do { } while (0)