Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=8e18257d29238311e82085152741f0c3aa18b74d
Commit:     8e18257d29238311e82085152741f0c3aa18b74d
Parent:     ca58abcb4a6d52ee2db1b1130cea3ca2a76677b9
Author:     Peter Zijlstra <[EMAIL PROTECTED]>
AuthorDate: Thu Jul 19 01:48:54 2007 -0700
Committer:  Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Thu Jul 19 10:04:49 2007 -0700

    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 <[EMAIL PROTECTED]>
    Acked-by: Ingo Molnar <[EMAIL PROTECTED]>
    Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
    Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
 kernel/lockdep.c      | 1171 ++++++++++++++++++++++++++-----------------------
 kernel/lockdep_proc.c |    2 +
 2 files changed, 630 insertions(+), 543 deletions(-)

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 05c1261..87ac364 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 58f35e5..2fde341 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",
-
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