Merge branch 'irq-threaded-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[pandora-kernel.git] / kernel / lockdep.c
index 28914a5..f74d2d7 100644 (file)
@@ -399,7 +399,6 @@ unsigned int nr_hardirq_chains;
 unsigned int nr_softirq_chains;
 unsigned int nr_process_chains;
 unsigned int max_lockdep_depth;
-unsigned int max_recursion_depth;
 
 #ifdef CONFIG_DEBUG_LOCKDEP
 /*
@@ -429,11 +428,8 @@ atomic_t redundant_softirqs_on;
 atomic_t redundant_softirqs_off;
 atomic_t nr_unused_locks;
 atomic_t nr_cyclic_checks;
-atomic_t nr_cyclic_check_recursions;
 atomic_t nr_find_usage_forwards_checks;
-atomic_t nr_find_usage_forwards_recursions;
 atomic_t nr_find_usage_backwards_checks;
-atomic_t nr_find_usage_backwards_recursions;
 #endif
 
 /*
@@ -861,14 +857,15 @@ struct circular_queue {
 };
 
 static struct circular_queue lock_cq;
-static unsigned long bfs_accessed[BITS_TO_LONGS(MAX_LOCKDEP_ENTRIES)];
 
 unsigned int max_bfs_queue_depth;
 
+static unsigned int lockdep_dependency_gen_id;
+
 static inline void __cq_init(struct circular_queue *cq)
 {
        cq->front = cq->rear = 0;
-       bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES);
+       lockdep_dependency_gen_id++;
 }
 
 static inline int __cq_empty(struct circular_queue *cq)
@@ -914,7 +911,7 @@ static inline void mark_lock_accessed(struct lock_list *lock,
        nr = lock - list_entries;
        WARN_ON(nr >= nr_list_entries);
        lock->parent = parent;
-       set_bit(nr, bfs_accessed);
+       lock->class->dep_gen_id = lockdep_dependency_gen_id;
 }
 
 static inline unsigned long lock_accessed(struct lock_list *lock)
@@ -923,7 +920,7 @@ static inline unsigned long lock_accessed(struct lock_list *lock)
 
        nr = lock - list_entries;
        WARN_ON(nr >= nr_list_entries);
-       return test_bit(nr, bfs_accessed);
+       return lock->class->dep_gen_id == lockdep_dependency_gen_id;
 }
 
 static inline struct lock_list *get_lock_parent(struct lock_list *child)
@@ -2708,13 +2705,15 @@ EXPORT_SYMBOL_GPL(lockdep_init_map);
  */
 static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
                          int trylock, int read, int check, int hardirqs_off,
-                         struct lockdep_map *nest_lock, unsigned long ip)
+                         struct lockdep_map *nest_lock, unsigned long ip,
+                         int references)
 {
        struct task_struct *curr = current;
        struct lock_class *class = NULL;
        struct held_lock *hlock;
        unsigned int depth, id;
        int chain_head = 0;
+       int class_idx;
        u64 chain_key;
 
        if (!prove_locking)
@@ -2762,10 +2761,24 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
        if (DEBUG_LOCKS_WARN_ON(depth >= MAX_LOCK_DEPTH))
                return 0;
 
+       class_idx = class - lock_classes + 1;
+
+       if (depth) {
+               hlock = curr->held_locks + depth - 1;
+               if (hlock->class_idx == class_idx && nest_lock) {
+                       if (hlock->references)
+                               hlock->references++;
+                       else
+                               hlock->references = 2;
+
+                       return 1;
+               }
+       }
+
        hlock = curr->held_locks + depth;
        if (DEBUG_LOCKS_WARN_ON(!class))
                return 0;
-       hlock->class_idx = class - lock_classes + 1;
+       hlock->class_idx = class_idx;
        hlock->acquire_ip = ip;
        hlock->instance = lock;
        hlock->nest_lock = nest_lock;
@@ -2773,6 +2786,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
        hlock->read = read;
        hlock->check = check;
        hlock->hardirqs_off = !!hardirqs_off;
+       hlock->references = references;
 #ifdef CONFIG_LOCK_STAT
        hlock->waittime_stamp = 0;
        hlock->holdtime_stamp = sched_clock();
@@ -2881,6 +2895,30 @@ static int check_unlock(struct task_struct *curr, struct lockdep_map *lock,
        return 1;
 }
 
+static int match_held_lock(struct held_lock *hlock, struct lockdep_map *lock)
+{
+       if (hlock->instance == lock)
+               return 1;
+
+       if (hlock->references) {
+               struct lock_class *class = lock->class_cache;
+
+               if (!class)
+                       class = look_up_lock_class(lock, 0);
+
+               if (DEBUG_LOCKS_WARN_ON(!class))
+                       return 0;
+
+               if (DEBUG_LOCKS_WARN_ON(!hlock->nest_lock))
+                       return 0;
+
+               if (hlock->class_idx == class - lock_classes + 1)
+                       return 1;
+       }
+
+       return 0;
+}
+
 static int
 __lock_set_class(struct lockdep_map *lock, const char *name,
                 struct lock_class_key *key, unsigned int subclass,
@@ -2904,7 +2942,7 @@ __lock_set_class(struct lockdep_map *lock, const char *name,
                 */
                if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
                        break;
-               if (hlock->instance == lock)
+               if (match_held_lock(hlock, lock))
                        goto found_it;
                prev_hlock = hlock;
        }
@@ -2923,7 +2961,8 @@ found_it:
                if (!__lock_acquire(hlock->instance,
                        hlock_class(hlock)->subclass, hlock->trylock,
                                hlock->read, hlock->check, hlock->hardirqs_off,
-                               hlock->nest_lock, hlock->acquire_ip))
+                               hlock->nest_lock, hlock->acquire_ip,
+                               hlock->references))
                        return 0;
        }
 
@@ -2962,20 +3001,34 @@ lock_release_non_nested(struct task_struct *curr,
                 */
                if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
                        break;
-               if (hlock->instance == lock)
+               if (match_held_lock(hlock, lock))
                        goto found_it;
                prev_hlock = hlock;
        }
        return print_unlock_inbalance_bug(curr, lock, ip);
 
 found_it:
-       lock_release_holdtime(hlock);
+       if (hlock->instance == lock)
+               lock_release_holdtime(hlock);
+
+       if (hlock->references) {
+               hlock->references--;
+               if (hlock->references) {
+                       /*
+                        * We had, and after removing one, still have
+                        * references, the current lock stack is still
+                        * valid. We're done!
+                        */
+                       return 1;
+               }
+       }
 
        /*
         * We have the right lock to unlock, 'hlock' points to it.
         * Now we remove it from the stack, and add back the other
         * entries (if any), recalculating the hash along the way:
         */
+
        curr->lockdep_depth = i;
        curr->curr_chain_key = hlock->prev_chain_key;
 
@@ -2984,7 +3037,8 @@ found_it:
                if (!__lock_acquire(hlock->instance,
                        hlock_class(hlock)->subclass, hlock->trylock,
                                hlock->read, hlock->check, hlock->hardirqs_off,
-                               hlock->nest_lock, hlock->acquire_ip))
+                               hlock->nest_lock, hlock->acquire_ip,
+                               hlock->references))
                        return 0;
        }
 
@@ -3014,7 +3068,7 @@ static int lock_release_nested(struct task_struct *curr,
        /*
         * Is the unlock non-nested:
         */
-       if (hlock->instance != lock)
+       if (hlock->instance != lock || hlock->references)
                return lock_release_non_nested(curr, lock, ip);
        curr->lockdep_depth--;
 
@@ -3065,7 +3119,9 @@ static int __lock_is_held(struct lockdep_map *lock)
        int i;
 
        for (i = 0; i < curr->lockdep_depth; i++) {
-               if (curr->held_locks[i].instance == lock)
+               struct held_lock *hlock = curr->held_locks + i;
+
+               if (match_held_lock(hlock, lock))
                        return 1;
        }
 
@@ -3148,7 +3204,7 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 
        current->lockdep_recursion = 1;
        __lock_acquire(lock, subclass, trylock, read, check,
-                      irqs_disabled_flags(flags), nest_lock, ip);
+                      irqs_disabled_flags(flags), nest_lock, ip, 0);
        current->lockdep_recursion = 0;
        raw_local_irq_restore(flags);
 }
@@ -3252,7 +3308,7 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip)
                 */
                if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
                        break;
-               if (hlock->instance == lock)
+               if (match_held_lock(hlock, lock))
                        goto found_it;
                prev_hlock = hlock;
        }
@@ -3260,6 +3316,9 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip)
        return;
 
 found_it:
+       if (hlock->instance != lock)
+               return;
+
        hlock->waittime_stamp = sched_clock();
 
        contention_point = lock_point(hlock_class(hlock)->contention_point, ip);
@@ -3299,7 +3358,7 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip)
                 */
                if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
                        break;
-               if (hlock->instance == lock)
+               if (match_held_lock(hlock, lock))
                        goto found_it;
                prev_hlock = hlock;
        }
@@ -3307,6 +3366,9 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip)
        return;
 
 found_it:
+       if (hlock->instance != lock)
+               return;
+
        cpu = smp_processor_id();
        if (hlock->waittime_stamp) {
                now = sched_clock();
@@ -3537,10 +3599,11 @@ void __init lockdep_info(void)
                sizeof(struct list_head) * CLASSHASH_SIZE +
                sizeof(struct lock_list) * MAX_LOCKDEP_ENTRIES +
                sizeof(struct lock_chain) * MAX_LOCKDEP_CHAINS +
-               sizeof(struct list_head) * CHAINHASH_SIZE) / 1024
+               sizeof(struct list_head) * CHAINHASH_SIZE
 #ifdef CONFIG_PROVE_LOCKING
-               + sizeof(struct circular_queue) + sizeof(bfs_accessed)
+               + sizeof(struct circular_queue)
 #endif
+               ) / 1024
                );
 
        printk(" per task-struct memory footprint: %lu bytes\n",