lockdep: reduce the ifdeffery

Move code around to get fewer but larger #ifdef sections.  Break some
in-function #ifdefs out into their own functions.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 630 insertions, 543 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 05c1261791f4..87ac36425070 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -95,25 +95,6 @@ static int lockdep_initialized;
 unsigned long nr_list_entries;
 static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
 
-#ifdef CONFIG_PROVE_LOCKING
-/*
- * Allocate a lockdep entry. (assumes the graph_lock held, returns
- * with NULL on failure)
- */
-static struct lock_list *alloc_list_entry(void)
-{
-        if (nr_list_entries >= MAX_LOCKDEP_ENTRIES) {
-                if (!debug_locks_off_graph_unlock())
-                        return NULL;
-
-                printk("BUG: MAX_LOCKDEP_ENTRIES too low!\n");
-                printk("turning off the locking correctness validator.\n");
-                return NULL;
-        }
-        return list_entries + nr_list_entries++;
-}
-#endif
-
 /*
  * All data structures here are protected by the global debug_lock.
  *
@@ -141,11 +122,6 @@ LIST_HEAD(all_lock_classes);
 
 static struct list_head classhash_table[CLASSHASH_SIZE];
 
-unsigned long nr_lock_chains;
-#ifdef CONFIG_PROVE_LOCKING
-static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
-#endif
-
 /*
  * We put the lock dependency chains into a hash-table as well, to cache
  * their existence:
@@ -227,26 +203,6 @@ static int verbose(struct lock_class *class)
         return 0;
 }
 
-#ifdef CONFIG_TRACE_IRQFLAGS
-
-static int hardirq_verbose(struct lock_class *class)
-{
-#if HARDIRQ_VERBOSE
-        return class_filter(class);
-#endif
-        return 0;
-}
-
-static int softirq_verbose(struct lock_class *class)
-{
-#if SOFTIRQ_VERBOSE
-        return class_filter(class);
-#endif
-        return 0;
-}
-
-#endif
-
 /*
  * Stack-trace: tightly packed array of stack backtrace
  * addresses. Protected by the graph_lock.
@@ -486,8 +442,258 @@ static void print_lock_dependencies(struct lock_class *class, int depth)
         }
 }
 
+static void print_kernel_version(void)
+{
+        printk("%s %.*s\n", init_utsname()->release,
+                (int)strcspn(init_utsname()->version, " "),
+                init_utsname()->version);
+}
+
+static int very_verbose(struct lock_class *class)
+{
+#if VERY_VERBOSE
+        return class_filter(class);
+#endif
+        return 0;
+}
+
+/*
+ * Is this the address of a static object:
+ */
+static int static_obj(void *obj)
+{
+        unsigned long start = (unsigned long) &_stext,
+                      end   = (unsigned long) &_end,
+                      addr  = (unsigned long) obj;
+#ifdef CONFIG_SMP
+        int i;
+#endif
+
+        /*
+         * static variable?
+         */
+        if ((addr >= start) && (addr < end))
+                return 1;
+
+#ifdef CONFIG_SMP
+        /*
+         * percpu var?
+         */
+        for_each_possible_cpu(i) {
+                start = (unsigned long) &__per_cpu_start + per_cpu_offset(i);
+                end   = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM
+                                        + per_cpu_offset(i);
+
+                if ((addr >= start) && (addr < end))
+                        return 1;
+        }
+#endif
+
+        /*
+         * module var?
+         */
+        return is_module_address(addr);
+}
+
+/*
+ * To make lock name printouts unique, we calculate a unique
+ * class->name_version generation counter:
+ */
+static int count_matching_names(struct lock_class *new_class)
+{
+        struct lock_class *class;
+        int count = 0;
+
+        if (!new_class->name)
+                return 0;
+
+        list_for_each_entry(class, &all_lock_classes, lock_entry) {
+                if (new_class->key - new_class->subclass == class->key)
+                        return class->name_version;
+                if (class->name && !strcmp(class->name, new_class->name))
+                        count = max(count, class->name_version);
+        }
+
+        return count + 1;
+}
+
+/*
+ * Register a lock's class in the hash-table, if the class is not present
+ * yet. Otherwise we look it up. We cache the result in the lock object
+ * itself, so actual lookup of the hash should be once per lock object.
+ */
+static inline struct lock_class *
+look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
+{
+        struct lockdep_subclass_key *key;
+        struct list_head *hash_head;
+        struct lock_class *class;
+
+#ifdef CONFIG_DEBUG_LOCKDEP
+        /*
+         * If the architecture calls into lockdep before initializing
+         * the hashes then we'll warn about it later. (we cannot printk
+         * right now)
+         */
+        if (unlikely(!lockdep_initialized)) {
+                lockdep_init();
+                lockdep_init_error = 1;
+        }
+#endif
+
+        /*
+         * Static locks do not have their class-keys yet - for them the key
+         * is the lock object itself:
+         */
+        if (unlikely(!lock->key))
+                lock->key = (void *)lock;
+
+        /*
+         * NOTE: the class-key must be unique. For dynamic locks, a static
+         * lock_class_key variable is passed in through the mutex_init()
+         * (or spin_lock_init()) call - which acts as the key. For static
+         * locks we use the lock object itself as the key.
+         */
+        BUILD_BUG_ON(sizeof(struct lock_class_key) > sizeof(struct lock_class));
+
+        key = lock->key->subkeys + subclass;
+
+        hash_head = classhashentry(key);
+
+        /*
+         * We can walk the hash lockfree, because the hash only
+         * grows, and we are careful when adding entries to the end:
+         */
+        list_for_each_entry(class, hash_head, hash_entry)
+                if (class->key == key)
+                        return class;
+
+        return NULL;
+}
+
+/*
+ * Register a lock's class in the hash-table, if the class is not present
+ * yet. Otherwise we look it up. We cache the result in the lock object
+ * 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, int force)
+{
+        struct lockdep_subclass_key *key;
+        struct list_head *hash_head;
+        struct lock_class *class;
+        unsigned long flags;
+
+        class = look_up_lock_class(lock, subclass);
+        if (likely(class))
+                return class;
+
+        /*
+         * Debug-check: all keys must be persistent!
+         */
+        if (!static_obj(lock->key)) {
+                debug_locks_off();
+                printk("INFO: trying to register non-static key.\n");
+                printk("the code is fine but needs lockdep annotation.\n");
+                printk("turning off the locking correctness validator.\n");
+                dump_stack();
+
+                return NULL;
+        }
+
+        key = lock->key->subkeys + subclass;
+        hash_head = classhashentry(key);
+
+        raw_local_irq_save(flags);
+        if (!graph_lock()) {
+                raw_local_irq_restore(flags);
+                return NULL;
+        }
+        /*
+         * We have to do the hash-walk again, to avoid races
+         * with another CPU:
+         */
+        list_for_each_entry(class, hash_head, hash_entry)
+                if (class->key == key)
+                        goto out_unlock_set;
+        /*
+         * Allocate a new key from the static array, and add it to
+         * the hash:
+         */
+        if (nr_lock_classes >= MAX_LOCKDEP_KEYS) {
+                if (!debug_locks_off_graph_unlock()) {
+                        raw_local_irq_restore(flags);
+                        return NULL;
+                }
+                raw_local_irq_restore(flags);
+
+                printk("BUG: MAX_LOCKDEP_KEYS too low!\n");
+                printk("turning off the locking correctness validator.\n");
+                return NULL;
+        }
+        class = lock_classes + nr_lock_classes++;
+        debug_atomic_inc(&nr_unused_locks);
+        class->key = key;
+        class->name = lock->name;
+        class->subclass = subclass;
+        INIT_LIST_HEAD(&class->lock_entry);
+        INIT_LIST_HEAD(&class->locks_before);
+        INIT_LIST_HEAD(&class->locks_after);
+        class->name_version = count_matching_names(class);
+        /*
+         * We use RCU's safe list-add method to make
+         * parallel walking of the hash-list safe:
+         */
+        list_add_tail_rcu(&class->hash_entry, hash_head);
+
+        if (verbose(class)) {
+                graph_unlock();
+                raw_local_irq_restore(flags);
+
+                printk("\nnew class %p: %s", class->key, class->name);
+                if (class->name_version > 1)
+                        printk("#%d", class->name_version);
+                printk("\n");
+                dump_stack();
+
+                raw_local_irq_save(flags);
+                if (!graph_lock()) {
+                        raw_local_irq_restore(flags);
+                        return NULL;
+                }
+        }
+out_unlock_set:
+        graph_unlock();
+        raw_local_irq_restore(flags);
+
+        if (!subclass || force)
+                lock->class_cache = class;
+
+        if (DEBUG_LOCKS_WARN_ON(class->subclass != subclass))
+                return NULL;
+
+        return class;
+}
+
 #ifdef CONFIG_PROVE_LOCKING
 /*
+ * Allocate a lockdep entry. (assumes the graph_lock held, returns
+ * with NULL on failure)
+ */
+static struct lock_list *alloc_list_entry(void)
+{
+        if (nr_list_entries >= MAX_LOCKDEP_ENTRIES) {
+                if (!debug_locks_off_graph_unlock())
+                        return NULL;
+
+                printk("BUG: MAX_LOCKDEP_ENTRIES too low!\n");
+                printk("turning off the locking correctness validator.\n");
+                return NULL;
+        }
+        return list_entries + nr_list_entries++;
+}
+
+/*
  * Add a new dependency to the head of the list:
  */
 static int add_lock_to_list(struct lock_class *class, struct lock_class *this,
@@ -546,16 +752,7 @@ print_circular_bug_entry(struct lock_list *target, unsigned int depth)
 
         return 0;
 }
-#endif
 
-static void print_kernel_version(void)
-{
-        printk("%s %.*s\n", init_utsname()->release,
-                (int)strcspn(init_utsname()->version, " "),
-                init_utsname()->version);
-}
-
-#ifdef CONFIG_PROVE_LOCKING
 /*
  * When a circular dependency is detected, print the
  * header first:
@@ -646,17 +843,8 @@ check_noncircular(struct lock_class *source, unsigned int depth)
         }
         return 1;
 }
-#endif
 
-static int very_verbose(struct lock_class *class)
-{
-#if VERY_VERBOSE
-        return class_filter(class);
-#endif
-        return 0;
-}
 #ifdef CONFIG_TRACE_IRQFLAGS
-
 /*
  * Forwards and backwards subgraph searching, for the purposes of
  * proving that two subgraphs can be connected by a new dependency
@@ -829,9 +1017,80 @@ check_usage(struct task_struct *curr, struct held_lock *prev,
                         bit_backwards, bit_forwards, irqclass);
 }
 
+static int
+check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
+                struct held_lock *next)
+{
+        /*
+         * Prove that the new dependency does not connect a hardirq-safe
+         * lock with a hardirq-unsafe lock - to achieve this we search
+         * the backwards-subgraph starting at <prev>, and the
+         * forwards-subgraph starting at <next>:
+         */
+        if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ,
+                                        LOCK_ENABLED_HARDIRQS, "hard"))
+                return 0;
+
+        /*
+         * Prove that the new dependency does not connect a hardirq-safe-read
+         * lock with a hardirq-unsafe lock - to achieve this we search
+         * the backwards-subgraph starting at <prev>, and the
+         * forwards-subgraph starting at <next>:
+         */
+        if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ_READ,
+                                        LOCK_ENABLED_HARDIRQS, "hard-read"))
+                return 0;
+
+        /*
+         * Prove that the new dependency does not connect a softirq-safe
+         * lock with a softirq-unsafe lock - to achieve this we search
+         * the backwards-subgraph starting at <prev>, and the
+         * forwards-subgraph starting at <next>:
+         */
+        if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ,
+                                        LOCK_ENABLED_SOFTIRQS, "soft"))
+                return 0;
+        /*
+         * Prove that the new dependency does not connect a softirq-safe-read
+         * lock with a softirq-unsafe lock - to achieve this we search
+         * the backwards-subgraph starting at <prev>, and the
+         * forwards-subgraph starting at <next>:
+         */
+        if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ_READ,
+                                        LOCK_ENABLED_SOFTIRQS, "soft"))
+                return 0;
+
+        return 1;
+}
+
+static void inc_chains(void)
+{
+        if (current->hardirq_context)
+                nr_hardirq_chains++;
+        else {
+                if (current->softirq_context)
+                        nr_softirq_chains++;
+                else
+                        nr_process_chains++;
+        }
+}
+
+#else
+
+static inline int
+check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
+                struct held_lock *next)
+{
+        return 1;
+}
+
+static inline void inc_chains(void)
+{
+        nr_process_chains++;
+}
+
 #endif
 
-#ifdef CONFIG_PROVE_LOCKING
 static int
 print_deadlock_bug(struct task_struct *curr, struct held_lock *prev,
                    struct held_lock *next)
@@ -931,47 +1190,10 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
         if (!(check_noncircular(next->class, 0)))
                 return print_circular_bug_tail();
 
-#ifdef CONFIG_TRACE_IRQFLAGS
-        /*
-         * Prove that the new dependency does not connect a hardirq-safe
-         * lock with a hardirq-unsafe lock - to achieve this we search
-         * the backwards-subgraph starting at <prev>, and the
-         * forwards-subgraph starting at <next>:
-         */
-        if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ,
-                                        LOCK_ENABLED_HARDIRQS, "hard"))
-                return 0;
-
-        /*
-         * Prove that the new dependency does not connect a hardirq-safe-read
-         * lock with a hardirq-unsafe lock - to achieve this we search
-         * the backwards-subgraph starting at <prev>, and the
-         * forwards-subgraph starting at <next>:
-         */
-        if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ_READ,
-                                        LOCK_ENABLED_HARDIRQS, "hard-read"))
+        if (!check_prev_add_irq(curr, prev, next))
                 return 0;
 
         /*
-         * Prove that the new dependency does not connect a softirq-safe
-         * lock with a softirq-unsafe lock - to achieve this we search
-         * the backwards-subgraph starting at <prev>, and the
-         * forwards-subgraph starting at <next>:
-         */
-        if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ,
-                                        LOCK_ENABLED_SOFTIRQS, "soft"))
-                return 0;
-        /*
-         * Prove that the new dependency does not connect a softirq-safe-read
-         * lock with a softirq-unsafe lock - to achieve this we search
-         * the backwards-subgraph starting at <prev>, and the
-         * forwards-subgraph starting at <next>:
-         */
-        if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ_READ,
-                                        LOCK_ENABLED_SOFTIRQS, "soft"))
-                return 0;
-#endif
-        /*
          * For recursive read-locks we do all the dependency checks,
          * but we dont store read-triggered dependencies (only
          * write-triggered dependencies). This ensures that only the
@@ -1096,227 +1318,10 @@ out_bug:
 
         return 0;
 }
-#endif
-
-/*
- * Is this the address of a static object:
- */
-static int static_obj(void *obj)
-{
-        unsigned long start = (unsigned long) &_stext,
-                      end   = (unsigned long) &_end,
-                      addr  = (unsigned long) obj;
-#ifdef CONFIG_SMP
-        int i;
-#endif
-
-        /*
-         * static variable?
-         */
-        if ((addr >= start) && (addr < end))
-                return 1;
-
-#ifdef CONFIG_SMP
-        /*
-         * percpu var?
-         */
-        for_each_possible_cpu(i) {
-                start = (unsigned long) &__per_cpu_start + per_cpu_offset(i);
-                end   = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM
-                                        + per_cpu_offset(i);
-
-                if ((addr >= start) && (addr < end))
-                        return 1;
-        }
-#endif
-
-        /*
-         * module var?
-         */
-        return is_module_address(addr);
-}
-
-/*
- * To make lock name printouts unique, we calculate a unique
- * class->name_version generation counter:
- */
-static int count_matching_names(struct lock_class *new_class)
-{
-        struct lock_class *class;
-        int count = 0;
-
-        if (!new_class->name)
-                return 0;
-
-        list_for_each_entry(class, &all_lock_classes, lock_entry) {
-                if (new_class->key - new_class->subclass == class->key)
-                        return class->name_version;
-                if (class->name && !strcmp(class->name, new_class->name))
-                        count = max(count, class->name_version);
-        }
-
-        return count + 1;
-}
-
-/*
- * Register a lock's class in the hash-table, if the class is not present
- * yet. Otherwise we look it up. We cache the result in the lock object
- * itself, so actual lookup of the hash should be once per lock object.
- */
-static inline struct lock_class *
-look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
-{
-        struct lockdep_subclass_key *key;
-        struct list_head *hash_head;
-        struct lock_class *class;
-
-#ifdef CONFIG_DEBUG_LOCKDEP
-        /*
-         * If the architecture calls into lockdep before initializing
-         * the hashes then we'll warn about it later. (we cannot printk
-         * right now)
-         */
-        if (unlikely(!lockdep_initialized)) {
-                lockdep_init();
-                lockdep_init_error = 1;
-        }
-#endif
-
-        /*
-         * Static locks do not have their class-keys yet - for them the key
-         * is the lock object itself:
-         */
-        if (unlikely(!lock->key))
-                lock->key = (void *)lock;
-
-        /*
-         * NOTE: the class-key must be unique. For dynamic locks, a static
-         * lock_class_key variable is passed in through the mutex_init()
-         * (or spin_lock_init()) call - which acts as the key. For static
-         * locks we use the lock object itself as the key.
-         */
-        BUILD_BUG_ON(sizeof(struct lock_class_key) > sizeof(struct lock_class));
-
-        key = lock->key->subkeys + subclass;
-
-        hash_head = classhashentry(key);
-
-        /*
-         * We can walk the hash lockfree, because the hash only
-         * grows, and we are careful when adding entries to the end:
-         */
-        list_for_each_entry(class, hash_head, hash_entry)
-                if (class->key == key)
-                        return class;
-
-        return NULL;
-}
-
-/*
- * Register a lock's class in the hash-table, if the class is not present
- * yet. Otherwise we look it up. We cache the result in the lock object
- * 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, int force)
-{
-        struct lockdep_subclass_key *key;
-        struct list_head *hash_head;
-        struct lock_class *class;
-        unsigned long flags;
-
-        class = look_up_lock_class(lock, subclass);
-        if (likely(class))
-                return class;
-
-        /*
-         * Debug-check: all keys must be persistent!
-         */
-        if (!static_obj(lock->key)) {
-                debug_locks_off();
-                printk("INFO: trying to register non-static key.\n");
-                printk("the code is fine but needs lockdep annotation.\n");
-                printk("turning off the locking correctness validator.\n");
-                dump_stack();
 
-                return NULL;
-        }
-
-        key = lock->key->subkeys + subclass;
-        hash_head = classhashentry(key);
-
-        raw_local_irq_save(flags);
-        if (!graph_lock()) {
-                raw_local_irq_restore(flags);
-                return NULL;
-        }
-        /*
-         * We have to do the hash-walk again, to avoid races
-         * with another CPU:
-         */
-        list_for_each_entry(class, hash_head, hash_entry)
-                if (class->key == key)
-                        goto out_unlock_set;
-        /*
-         * Allocate a new key from the static array, and add it to
-         * the hash:
-         */
-        if (nr_lock_classes >= MAX_LOCKDEP_KEYS) {
-                if (!debug_locks_off_graph_unlock()) {
-                        raw_local_irq_restore(flags);
-                        return NULL;
-                }
-                raw_local_irq_restore(flags);
-
-                printk("BUG: MAX_LOCKDEP_KEYS too low!\n");
-                printk("turning off the locking correctness validator.\n");
-                return NULL;
-        }
-        class = lock_classes + nr_lock_classes++;
-        debug_atomic_inc(&nr_unused_locks);
-        class->key = key;
-        class->name = lock->name;
-        class->subclass = subclass;
-        INIT_LIST_HEAD(&class->lock_entry);
-        INIT_LIST_HEAD(&class->locks_before);
-        INIT_LIST_HEAD(&class->locks_after);
-        class->name_version = count_matching_names(class);
-        /*
-         * We use RCU's safe list-add method to make
-         * parallel walking of the hash-list safe:
-         */
-        list_add_tail_rcu(&class->hash_entry, hash_head);
-
-        if (verbose(class)) {
-                graph_unlock();
-                raw_local_irq_restore(flags);
-
-                printk("\nnew class %p: %s", class->key, class->name);
-                if (class->name_version > 1)
-                        printk("#%d", class->name_version);
-                printk("\n");
-                dump_stack();
-
-                raw_local_irq_save(flags);
-                if (!graph_lock()) {
-                        raw_local_irq_restore(flags);
-                        return NULL;
-                }
-        }
-out_unlock_set:
-        graph_unlock();
-        raw_local_irq_restore(flags);
-
-        if (!subclass || force)
-                lock->class_cache = class;
-
-        if (DEBUG_LOCKS_WARN_ON(class->subclass != subclass))
-                return NULL;
-
-        return class;
-}
+unsigned long nr_lock_chains;
+static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
 
-#ifdef CONFIG_PROVE_LOCKING
 /*
  * Look up a dependency chain. If the key is not present yet then
  * add it and return 1 - in this case the new dependency chain is
@@ -1376,21 +1381,71 @@ cache_hit:
         chain->chain_key = chain_key;
         list_add_tail_rcu(&chain->entry, hash_head);
         debug_atomic_inc(&chain_lookup_misses);
-#ifdef CONFIG_TRACE_IRQFLAGS
-        if (current->hardirq_context)
-                nr_hardirq_chains++;
-        else {
-                if (current->softirq_context)
-                        nr_softirq_chains++;
-                else
-                        nr_process_chains++;
-        }
-#else
-        nr_process_chains++;
-#endif
+        inc_chains();
+
+        return 1;
+}
+
+static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
+                struct held_lock *hlock, int chain_head)
+{
+        /*
+         * Trylock needs to maintain the stack of held locks, but it
+         * does not add new dependencies, because trylock can be done
+         * in any order.
+         *
+         * We look up the chain_key and do the O(N^2) check and update of
+         * the dependencies only if this is a new dependency chain.
+         * (If lookup_chain_cache() returns with 1 it acquires
+         * graph_lock for us)
+         */
+        if (!hlock->trylock && (hlock->check == 2) &&
+                        lookup_chain_cache(curr->curr_chain_key, hlock->class)) {
+                /*
+                 * Check whether last held lock:
+                 *
+                 * - is irq-safe, if this lock is irq-unsafe
+                 * - is softirq-safe, if this lock is hardirq-unsafe
+                 *
+                 * And check whether the new lock's dependency graph
+                 * could lead back to the previous lock.
+                 *
+                 * any of these scenarios could lead to a deadlock. If
+                 * All validations
+                 */
+                int ret = check_deadlock(curr, hlock, lock, hlock->read);
+
+                if (!ret)
+                        return 0;
+                /*
+                 * Mark recursive read, as we jump over it when
+                 * building dependencies (just like we jump over
+                 * trylock entries):
+                 */
+                if (ret == 2)
+                        hlock->read = 2;
+                /*
+                 * Add dependency only if this lock is not the head
+                 * of the chain, and if it's not a secondary read-lock:
+                 */
+                if (!chain_head && ret != 2)
+                        if (!check_prevs_add(curr, hlock))
+                                return 0;
+                graph_unlock();
+        } else
+                /* after lookup_chain_cache(): */
+                if (unlikely(!debug_locks))
+                        return 0;
 
         return 1;
 }
+#else
+static inline int validate_chain(struct task_struct *curr,
+                struct lockdep_map *lock, struct held_lock *hlock,
+                int chain_head)
+{
+        return 1;
+}
 #endif
 
 /*
@@ -1436,6 +1491,57 @@ static void check_chain_key(struct task_struct *curr)
 #endif
 }
 
+static int
+print_usage_bug(struct task_struct *curr, struct held_lock *this,
+                enum lock_usage_bit prev_bit, enum lock_usage_bit new_bit)
+{
+        if (!debug_locks_off_graph_unlock() || debug_locks_silent)
+                return 0;
+
+        printk("\n=================================\n");
+        printk(  "[ INFO: inconsistent lock state ]\n");
+        print_kernel_version();
+        printk(  "---------------------------------\n");
+
+        printk("inconsistent {%s} -> {%s} usage.\n",
+                usage_str[prev_bit], usage_str[new_bit]);
+
+        printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] takes:\n",
+                curr->comm, curr->pid,
+                trace_hardirq_context(curr), hardirq_count() >> HARDIRQ_SHIFT,
+                trace_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
+                trace_hardirqs_enabled(curr),
+                trace_softirqs_enabled(curr));
+        print_lock(this);
+
+        printk("{%s} state was registered at:\n", usage_str[prev_bit]);
+        print_stack_trace(this->class->usage_traces + prev_bit, 1);
+
+        print_irqtrace_events(curr);
+        printk("\nother info that might help us debug this:\n");
+        lockdep_print_held_locks(curr);
+
+        printk("\nstack backtrace:\n");
+        dump_stack();
+
+        return 0;
+}
+
+/*
+ * Print out an error if an invalid bit is set:
+ */
+static inline int
+valid_state(struct task_struct *curr, struct held_lock *this,
+            enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit)
+{
+        if (unlikely(this->class->usage_mask & (1 << bad_bit)))
+                return print_usage_bug(curr, this, bad_bit, new_bit);
+        return 1;
+}
+
+static int mark_lock(struct task_struct *curr, struct held_lock *this,
+                     enum lock_usage_bit new_bit);
+
 #ifdef CONFIG_TRACE_IRQFLAGS
 
 /*
@@ -1529,90 +1635,30 @@ void print_irqtrace_events(struct task_struct *curr)
         print_ip_sym(curr->softirq_disable_ip);
 }
 
-#endif
-
-static int
-print_usage_bug(struct task_struct *curr, struct held_lock *this,
-                enum lock_usage_bit prev_bit, enum lock_usage_bit new_bit)
+static int hardirq_verbose(struct lock_class *class)
 {
-        if (!debug_locks_off_graph_unlock() || debug_locks_silent)
-                return 0;
-
-        printk("\n=================================\n");
-        printk(  "[ INFO: inconsistent lock state ]\n");
-        print_kernel_version();
-        printk(  "---------------------------------\n");
-
-        printk("inconsistent {%s} -> {%s} usage.\n",
-                usage_str[prev_bit], usage_str[new_bit]);
-
-        printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] takes:\n",
-                curr->comm, curr->pid,
-                trace_hardirq_context(curr), hardirq_count() >> HARDIRQ_SHIFT,
-                trace_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
-                trace_hardirqs_enabled(curr),
-                trace_softirqs_enabled(curr));
-        print_lock(this);
-
-        printk("{%s} state was registered at:\n", usage_str[prev_bit]);
-        print_stack_trace(this->class->usage_traces + prev_bit, 1);
-
-        print_irqtrace_events(curr);
-        printk("\nother info that might help us debug this:\n");
-        lockdep_print_held_locks(curr);
-
-        printk("\nstack backtrace:\n");
-        dump_stack();
-
+#if HARDIRQ_VERBOSE
+        return class_filter(class);
+#endif
         return 0;
 }
 
-/*
- * Print out an error if an invalid bit is set:
- */
-static inline int
-valid_state(struct task_struct *curr, struct held_lock *this,
-            enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit)
+static int softirq_verbose(struct lock_class *class)
 {
-        if (unlikely(this->class->usage_mask & (1 << bad_bit)))
-                return print_usage_bug(curr, this, bad_bit, new_bit);
-        return 1;
+#if SOFTIRQ_VERBOSE
+        return class_filter(class);
+#endif
+        return 0;
 }
 
 #define STRICT_READ_CHECKS      1
 
-/*
- * Mark a lock with a usage bit, and validate the state transition:
- */
-static int mark_lock(struct task_struct *curr, struct held_lock *this,
-                     enum lock_usage_bit new_bit)
+static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
+                enum lock_usage_bit new_bit)
 {
-        unsigned int new_mask = 1 << new_bit, ret = 1;
-
-        /*
-         * If already set then do not dirty the cacheline,
-         * nor do any checks:
-         */
-        if (likely(this->class->usage_mask & new_mask))
-                return 1;
+        int ret = 1;
 
-        if (!graph_lock())
-                return 0;
-        /*
-         * Make sure we didnt race:
-         */
-        if (unlikely(this->class->usage_mask & new_mask)) {
-                graph_unlock();
-                return 1;
-        }
-
-        this->class->usage_mask |= new_mask;
-
-        if (!save_trace(this->class->usage_traces + new_bit))
-                return 0;
-
-        switch (new_bit) {
-#ifdef CONFIG_TRACE_IRQFLAGS
+        switch(new_bit) {
         case LOCK_USED_IN_HARDIRQ:
                 if (!valid_state(curr, this, new_bit, LOCK_ENABLED_HARDIRQS))
                         return 0;
@@ -1771,37 +1817,14 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
                 if (softirq_verbose(this->class))
                         ret = 2;
                 break;
-#endif
-        case LOCK_USED:
-                /*
-                 * Add it to the global list of classes:
-                 */
-                list_add_tail_rcu(&this->class->lock_entry, &all_lock_classes);
-                debug_atomic_dec(&nr_unused_locks);
-                break;
         default:
-                if (!debug_locks_off_graph_unlock())
-                        return 0;
                 WARN_ON(1);
-                return 0;
-        }
-
-        graph_unlock();
-
-        /*
-         * We must printk outside of the graph_lock:
-         */
-        if (ret == 2) {
-                printk("\nmarked lock as {%s}:\n", usage_str[new_bit]);
-                print_lock(this);
-                print_irqtrace_events(curr);
-                dump_stack();
+                break;
         }
 
         return ret;
 }
 
-#ifdef CONFIG_TRACE_IRQFLAGS
 /*
  * Mark all held locks with a usage bit:
  */
@@ -1984,9 +2007,176 @@ void trace_softirqs_off(unsigned long ip)
                 debug_atomic_inc(&redundant_softirqs_off);
 }
 
+static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock)
+{
+        /*
+         * If non-trylock use in a hardirq or softirq context, then
+         * mark the lock as used in these contexts:
+         */
+        if (!hlock->trylock) {
+                if (hlock->read) {
+                        if (curr->hardirq_context)
+                                if (!mark_lock(curr, hlock,
+                                                LOCK_USED_IN_HARDIRQ_READ))
+                                        return 0;
+                        if (curr->softirq_context)
+                                if (!mark_lock(curr, hlock,
+                                                LOCK_USED_IN_SOFTIRQ_READ))
+                                        return 0;
+                } else {
+                        if (curr->hardirq_context)
+                                if (!mark_lock(curr, hlock, LOCK_USED_IN_HARDIRQ))
+                                        return 0;
+                        if (curr->softirq_context)
+                                if (!mark_lock(curr, hlock, LOCK_USED_IN_SOFTIRQ))
+                                        return 0;
+                }
+        }
+        if (!hlock->hardirqs_off) {
+                if (hlock->read) {
+                        if (!mark_lock(curr, hlock,
+                                        LOCK_ENABLED_HARDIRQS_READ))
+                                return 0;
+                        if (curr->softirqs_enabled)
+                                if (!mark_lock(curr, hlock,
+                                                LOCK_ENABLED_SOFTIRQS_READ))
+                                        return 0;
+                } else {
+                        if (!mark_lock(curr, hlock,
+                                        LOCK_ENABLED_HARDIRQS))
+                                return 0;
+                        if (curr->softirqs_enabled)
+                                if (!mark_lock(curr, hlock,
+                                                LOCK_ENABLED_SOFTIRQS))
+                                        return 0;
+                }
+        }
+
+        return 1;
+}
+
+static int separate_irq_context(struct task_struct *curr,
+                struct held_lock *hlock)
+{
+        unsigned int depth = curr->lockdep_depth;
+
+        /*
+         * Keep track of points where we cross into an interrupt context:
+         */
+        hlock->irq_context = 2*(curr->hardirq_context ? 1 : 0) +
+                                curr->softirq_context;
+        if (depth) {
+                struct held_lock *prev_hlock;
+
+                prev_hlock = curr->held_locks + depth-1;
+                /*
+                 * If we cross into another context, reset the
+                 * hash key (this also prevents the checking and the
+                 * adding of the dependency to 'prev'):
+                 */
+                if (prev_hlock->irq_context != hlock->irq_context)
+                        return 1;
+        }
+        return 0;
+}
+
+#else
+
+static inline
+int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
+                enum lock_usage_bit new_bit)
+{
+        WARN_ON(1);
+        return 1;
+}
+
+static inline int mark_irqflags(struct task_struct *curr,
+                struct held_lock *hlock)
+{
+        return 1;
+}
+
+static inline int separate_irq_context(struct task_struct *curr,
+                struct held_lock *hlock)
+{
+        return 0;
+}
+
 #endif
 
 /*
+ * Mark a lock with a usage bit, and validate the state transition:
+ */
+static int mark_lock(struct task_struct *curr, struct held_lock *this,
+                     enum lock_usage_bit new_bit)
+{
+        unsigned int new_mask = 1 << new_bit, ret = 1;
+
+        /*
+         * If already set then do not dirty the cacheline,
+         * nor do any checks:
+         */
+        if (likely(this->class->usage_mask & new_mask))
+                return 1;
+
+        if (!graph_lock())
+                return 0;
+        /*
+         * Make sure we didnt race:
+         */
+        if (unlikely(this->class->usage_mask & new_mask)) {
+                graph_unlock();
+                return 1;
+        }
+
+        this->class->usage_mask |= new_mask;
+
+        if (!save_trace(this->class->usage_traces + new_bit))
+                return 0;
+
+        switch (new_bit) {
+        case LOCK_USED_IN_HARDIRQ:
+        case LOCK_USED_IN_SOFTIRQ:
+        case LOCK_USED_IN_HARDIRQ_READ:
+        case LOCK_USED_IN_SOFTIRQ_READ:
+        case LOCK_ENABLED_HARDIRQS:
+        case LOCK_ENABLED_SOFTIRQS:
+        case LOCK_ENABLED_HARDIRQS_READ:
+        case LOCK_ENABLED_SOFTIRQS_READ:
+                ret = mark_lock_irq(curr, this, new_bit);
+                if (!ret)
+                        return 0;
+                break;
+        case LOCK_USED:
+                /*
+                 * Add it to the global list of classes:
+                 */
+                list_add_tail_rcu(&this->class->lock_entry, &all_lock_classes);
+                debug_atomic_dec(&nr_unused_locks);
+                break;
+        default:
+                if (!debug_locks_off_graph_unlock())
+                        return 0;
+                WARN_ON(1);
+                return 0;
+        }
+
+        graph_unlock();
+
+        /*
+         * We must printk outside of the graph_lock:
+         */
+        if (ret == 2) {
+                printk("\nmarked lock as {%s}:\n", usage_str[new_bit]);
+                print_lock(this);
+                print_irqtrace_events(curr);
+                dump_stack();
+        }
+
+        return ret;
+}
+
+/*
  * Initialize a lock instance's lock-class mapping info:
  */
 void lockdep_init_map(struct lockdep_map *lock, const char *name,
@@ -2082,56 +2272,13 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
         hlock->check = check;
         hlock->hardirqs_off = hardirqs_off;
 
-        if (check != 2)
-                goto out_calc_hash;
-#ifdef CONFIG_TRACE_IRQFLAGS
-        /*
-         * If non-trylock use in a hardirq or softirq context, then
-         * mark the lock as used in these contexts:
-         */
-        if (!trylock) {
-                if (read) {
-                        if (curr->hardirq_context)
-                                if (!mark_lock(curr, hlock,
-                                                LOCK_USED_IN_HARDIRQ_READ))
-                                        return 0;
-                        if (curr->softirq_context)
-                                if (!mark_lock(curr, hlock,
-                                                LOCK_USED_IN_SOFTIRQ_READ))
-                                        return 0;
-                } else {
-                        if (curr->hardirq_context)
-                                if (!mark_lock(curr, hlock, LOCK_USED_IN_HARDIRQ))
-                                        return 0;
-                        if (curr->softirq_context)
-                                if (!mark_lock(curr, hlock, LOCK_USED_IN_SOFTIRQ))
-                                        return 0;
-                }
-        }
-        if (!hardirqs_off) {
-                if (read) {
-                        if (!mark_lock(curr, hlock,
-                                        LOCK_ENABLED_HARDIRQS_READ))
-                                return 0;
-                        if (curr->softirqs_enabled)
-                                if (!mark_lock(curr, hlock,
-                                                LOCK_ENABLED_SOFTIRQS_READ))
-                                        return 0;
-                } else {
-                        if (!mark_lock(curr, hlock,
-                                        LOCK_ENABLED_HARDIRQS))
-                                return 0;
-                        if (curr->softirqs_enabled)
-                                if (!mark_lock(curr, hlock,
-                                                LOCK_ENABLED_SOFTIRQS))
-                                        return 0;
-                }
-        }
-#endif
+        if (check == 2 && !mark_irqflags(curr, hlock))
+                return 0;
+
         /* mark it as used: */
         if (!mark_lock(curr, hlock, LOCK_USED))
                 return 0;
-out_calc_hash:
+
         /*
          * Calculate the chain hash: it's the combined has of all the
          * lock keys along the dependency chain. We save the hash value
@@ -2154,77 +2301,15 @@ out_calc_hash:
         }
 
         hlock->prev_chain_key = chain_key;
-
-#ifdef CONFIG_TRACE_IRQFLAGS
-        /*
-         * Keep track of points where we cross into an interrupt context:
-         */
-        hlock->irq_context = 2*(curr->hardirq_context ? 1 : 0) +
-                                curr->softirq_context;
-        if (depth) {
-                struct held_lock *prev_hlock;
-
-                prev_hlock = curr->held_locks + depth-1;
-                /*
-                 * If we cross into another context, reset the
-                 * hash key (this also prevents the checking and the
-                 * adding of the dependency to 'prev'):
-                 */
-                if (prev_hlock->irq_context != hlock->irq_context) {
-                        chain_key = 0;
-                        chain_head = 1;
-                }
+        if (separate_irq_context(curr, hlock)) {
+                chain_key = 0;
+                chain_head = 1;
         }
-#endif
         chain_key = iterate_chain_key(chain_key, id);
         curr->curr_chain_key = chain_key;
 
-        /*
-         * Trylock needs to maintain the stack of held locks, but it
-         * does not add new dependencies, because trylock can be done
-         * in any order.
-         *
-         * We look up the chain_key and do the O(N^2) check and update of
-         * the dependencies only if this is a new dependency chain.
-         * (If lookup_chain_cache() returns with 1 it acquires
-         * graph_lock for us)
-         */
-        if (!trylock && (check == 2) && lookup_chain_cache(chain_key, class)) {
-                /*
-                 * Check whether last held lock:
-                 *
-                 * - is irq-safe, if this lock is irq-unsafe
-                 * - is softirq-safe, if this lock is hardirq-unsafe
-                 *
-                 * And check whether the new lock's dependency graph
-                 * could lead back to the previous lock.
-                 *
-                 * any of these scenarios could lead to a deadlock. If
-                 * All validations
-                 */
-                int ret = check_deadlock(curr, hlock, lock, read);
-
-                if (!ret)
-                        return 0;
-                /*
-                 * Mark recursive read, as we jump over it when
-                 * building dependencies (just like we jump over
-                 * trylock entries):
-                 */
-                if (ret == 2)
-                        hlock->read = 2;
-                /*
-                 * Add dependency only if this lock is not the head
-                 * of the chain, and if it's not a secondary read-lock:
-                 */
-                if (!chain_head && ret != 2)
-                        if (!check_prevs_add(curr, hlock))
-                                return 0;
-                graph_unlock();
-        } else
-                /* after lookup_chain_cache(): */
-                if (unlikely(!debug_locks))
-                        return 0;
+        if (!validate_chain(curr, lock, hlock, chain_head))
+                return 0;
 
         curr->lockdep_depth++;
         check_chain_key(curr);
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index 58f35e586ee3..2fde34127e2e 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -271,8 +271,10 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
         if (nr_list_entries)
                 factor = sum_forward_deps / nr_list_entries;
 
+#ifdef CONFIG_PROVE_LOCKING
         seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",
                         nr_lock_chains, MAX_LOCKDEP_CHAINS);
+#endif
 
 #ifdef CONFIG_TRACE_IRQFLAGS
         seq_printf(m, " in-hardirq chains:             %11u\n",