pci: increase alignment to make more space for hidden code

[pandora-kernel.git] / kernel / futex.c

diff --git a/kernel/futex.c b/kernel/futex.c
index f92afbe..4949d33 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -916,8 +916,8 @@ retry:
        hb1 = hash_futex(&key1);
        hb2 = hash_futex(&key2);
 
-       double_lock_hb(hb1, hb2);
 retry_private:
+       double_lock_hb(hb1, hb2);
        op_ret = futex_atomic_op_inuser(op, uaddr2);
        if (unlikely(op_ret < 0)) {
 
@@ -1656,17 +1656,14 @@ out:
 static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q,
                                struct hrtimer_sleeper *timeout)
 {
-       queue_me(q, hb);
-
        /*
-        * There might have been scheduling since the queue_me(), as we
-        * cannot hold a spinlock across the get_user() in case it
-        * faults, and we cannot just set TASK_INTERRUPTIBLE state when
-        * queueing ourselves into the futex hash. This code thus has to
-        * rely on the futex_wake() code removing us from hash when it
-        * wakes us up.
+        * The task state is guaranteed to be set before another task can
+        * wake it. set_current_state() is implemented using set_mb() and
+        * queue_me() calls spin_unlock() upon completion, both serializing
+        * access to the hash list and forcing another memory barrier.
         */
        set_current_state(TASK_INTERRUPTIBLE);
+       queue_me(q, hb);
 
        /* Arm the timer */
        if (timeout) {
@@ -1676,8 +1673,8 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q,
        }
 
        /*
-        * !plist_node_empty() is safe here without any lock.
-        * q.lock_ptr != 0 is not safe, because of ordering against wakeup.
+        * If we have been removed from the hash list, then another task
+        * has tried to wake us, and we can skip the call to schedule().
         */
        if (likely(!plist_node_empty(&q->list))) {
                /*
@@ -2120,7 +2117,6 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
                 * Unqueue the futex_q and determine which it was.
                 */
                plist_del(&q->list, &q->list.plist);
-               drop_futex_key_refs(&q->key);
 
                if (timeout && !timeout->task)
                        ret = -ETIMEDOUT;