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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2006-10-11 01:45:14 -0400 |
|---|---|---|
| committer | Dmitry Torokhov <dtor@insightbb.com> | 2006-10-11 01:45:14 -0400 |
| commit | 4dfbb9d8c6cbfc32faa5c71145bd2a43e1f8237c (patch) | |
| tree | a4fefea0d5f5930240f4ecd6f9716a029cc927a9 /kernel/lockdep.c | |
| parent | 86255d9d0bede79140f4912482447963f00818c0 (diff) | |
| download | lwn-4dfbb9d8c6cbfc32faa5c71145bd2a43e1f8237c.tar.gz lwn-4dfbb9d8c6cbfc32faa5c71145bd2a43e1f8237c.zip | |
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>
Diffstat (limited to 'kernel/lockdep.c')
| -rw-r--r-- | kernel/lockdep.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 4c0553461000..ba7156ac70c1 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -1177,7 +1177,7 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass) * itself, so actual lookup of the hash should be once per lock object. */ static inline struct lock_class * -register_lock_class(struct lockdep_map *lock, unsigned int subclass) +register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force) { struct lockdep_subclass_key *key; struct list_head *hash_head; @@ -1249,7 +1249,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass) out_unlock_set: __raw_spin_unlock(&hash_lock); - if (!subclass) + if (!subclass || force) lock->class_cache = class; DEBUG_LOCKS_WARN_ON(class->subclass != subclass); @@ -1937,7 +1937,7 @@ void trace_softirqs_off(unsigned long ip) * Initialize a lock instance's lock-class mapping info: */ void lockdep_init_map(struct lockdep_map *lock, const char *name, - struct lock_class_key *key) + struct lock_class_key *key, int subclass) { if (unlikely(!debug_locks)) return; @@ -1957,6 +1957,8 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name, lock->name = name; lock->key = key; lock->class_cache = NULL; + if (subclass) + register_lock_class(lock, subclass, 1); } EXPORT_SYMBOL_GPL(lockdep_init_map); @@ -1995,7 +1997,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, * Not cached yet or subclass? */ if (unlikely(!class)) { - class = register_lock_class(lock, subclass); + class = register_lock_class(lock, subclass, 0); if (!class) return 0; } |