taskstats: remove initialization of static per-cpu variable

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / lockdep.c

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 65548eff029e4d61360d5a29626bce3f64ffaae1..d38a643629735b533c2e0ddff300a9881e1bf674 100644 (file)
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -1462,7 +1462,14 @@ out_bug:
 }
 
 unsigned long nr_lock_chains;
-static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
+struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
+int nr_chain_hlocks;
+static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
+
+struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
+{
+       return lock_classes + chain_hlocks[chain->base + i];
+}
 
 /*
  * Look up a dependency chain. If the key is not present yet then
@@ -1470,10 +1477,15 @@ static struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
  * validated. If the key is already hashed, return 0.
  * (On return with 1 graph_lock is held.)
  */
-static inline int lookup_chain_cache(u64 chain_key, struct lock_class *class)
+static inline int lookup_chain_cache(struct task_struct *curr,
+                                    struct held_lock *hlock,
+                                    u64 chain_key)
 {
+       struct lock_class *class = hlock->class;
        struct list_head *hash_head = chainhashentry(chain_key);
        struct lock_chain *chain;
+       struct held_lock *hlock_curr, *hlock_next;
+       int i, j, n, cn;
 
        if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
                return 0;
@@ -1521,6 +1533,32 @@ cache_hit:
        }
        chain = lock_chains + nr_lock_chains++;
        chain->chain_key = chain_key;
+       chain->irq_context = hlock->irq_context;
+       /* Find the first held_lock of current chain */
+       hlock_next = hlock;
+       for (i = curr->lockdep_depth - 1; i >= 0; i--) {
+               hlock_curr = curr->held_locks + i;
+               if (hlock_curr->irq_context != hlock_next->irq_context)
+                       break;
+               hlock_next = hlock;
+       }
+       i++;
+       chain->depth = curr->lockdep_depth + 1 - i;
+       cn = nr_chain_hlocks;
+       while (cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS) {
+               n = cmpxchg(&nr_chain_hlocks, cn, cn + chain->depth);
+               if (n == cn)
+                       break;
+               cn = n;
+       }
+       if (likely(cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
+               chain->base = cn;
+               for (j = 0; j < chain->depth - 1; j++, i++) {
+                       int lock_id = curr->held_locks[i].class - lock_classes;
+                       chain_hlocks[chain->base + j] = lock_id;
+               }
+               chain_hlocks[chain->base + j] = class - lock_classes;
+       }
        list_add_tail_rcu(&chain->entry, hash_head);
        debug_atomic_inc(&chain_lookup_misses);
        inc_chains();
@@ -1542,7 +1580,7 @@ static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
         * graph_lock for us)
         */
        if (!hlock->trylock && (hlock->check == 2) &&
-                       lookup_chain_cache(chain_key, hlock->class)) {
+           lookup_chain_cache(curr, hlock, chain_key)) {
                /*
                 * Check whether last held lock:
                 *
@@ -2668,7 +2706,8 @@ __lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
  */
 static void check_flags(unsigned long flags)
 {
-#if defined(CONFIG_DEBUG_LOCKDEP) && defined(CONFIG_TRACE_IRQFLAGS)
+#if defined(CONFIG_PROVE_LOCKING) && defined(CONFIG_DEBUG_LOCKDEP) && \
+    defined(CONFIG_TRACE_IRQFLAGS)
        if (!debug_locks)
                return;