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Merge branch 'tip/futex/devel' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-rt into core/futexes

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futex,plist: Pass the real head of the priority list to plist_del()
 futex,plist: Remove debug lock assignment from plist_node
 plist: Shrink struct plist_head
 plist: Add priority list test
This commit is contained in:
Thomas Gleixner
2011-03-12 11:37:14 +01:00
parent 8d7718aa08 6d55da53db
commit 995612178c
3 changed files with 162 additions and 60 deletions
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40
kernel/futex.c
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@@ -772,6 +772,24 @@ retry:
return ret;
}
/**
* __unqueue_futex() - Remove the futex_q from its futex_hash_bucket
* @q: The futex_q to unqueue
*
* The q->lock_ptr must not be NULL and must be held by the caller.
*/
static void __unqueue_futex(struct futex_q *q)
{
struct futex_hash_bucket *hb;
if (WARN_ON(!q->lock_ptr || !spin_is_locked(q->lock_ptr)
|| plist_node_empty(&q->list)))
return;
hb = container_of(q->lock_ptr, struct futex_hash_bucket, lock);
plist_del(&q->list, &hb->chain);
}
/*
* The hash bucket lock must be held when this is called.
* Afterwards, the futex_q must not be accessed.
@@ -789,7 +807,7 @@ static void wake_futex(struct futex_q *q)
*/
get_task_struct(p);
plist_del(&q->list, &q->list.plist);
__unqueue_futex(q);
/*
* The waiting task can free the futex_q as soon as
* q->lock_ptr = NULL is written, without taking any locks. A
@@ -1064,9 +1082,6 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1,
plist_del(&q->list, &hb1->chain);
plist_add(&q->list, &hb2->chain);
q->lock_ptr = &hb2->lock;
#ifdef CONFIG_DEBUG_PI_LIST
q->list.plist.spinlock = &hb2->lock;
#endif
}
get_futex_key_refs(key2);
q->key = *key2;
@@ -1093,16 +1108,12 @@ void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key,
get_futex_key_refs(key);
q->key = *key;
WARN_ON(plist_node_empty(&q->list));
plist_del(&q->list, &q->list.plist);
__unqueue_futex(q);
WARN_ON(!q->rt_waiter);
q->rt_waiter = NULL;
q->lock_ptr = &hb->lock;
#ifdef CONFIG_DEBUG_PI_LIST
q->list.plist.spinlock = &hb->lock;
#endif
wake_up_state(q->task, TASK_NORMAL);
}
@@ -1450,9 +1461,6 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
prio = min(current->normal_prio, MAX_RT_PRIO);
plist_node_init(&q->list, prio);
#ifdef CONFIG_DEBUG_PI_LIST
q->list.plist.spinlock = &hb->lock;
#endif
plist_add(&q->list, &hb->chain);
q->task = current;
spin_unlock(&hb->lock);
@@ -1497,8 +1505,7 @@ retry:
spin_unlock(lock_ptr);
goto retry;
}
WARN_ON(plist_node_empty(&q->list));
plist_del(&q->list, &q->list.plist);
__unqueue_futex(q);
BUG_ON(q->pi_state);
@@ -1518,8 +1525,7 @@ retry:
static void unqueue_me_pi(struct futex_q *q)
__releases(q->lock_ptr)
{
WARN_ON(plist_node_empty(&q->list));
plist_del(&q->list, &q->list.plist);
__unqueue_futex(q);
BUG_ON(!q->pi_state);
free_pi_state(q->pi_state);
@@ -2156,7 +2162,7 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
* We were woken prior to requeue by a timeout or a signal.
* Unqueue the futex_q and determine which it was.
*/
plist_del(&q->list, &q->list.plist);
plist_del(&q->list, &hb->chain);
/* Handle spurious wakeups gracefully */
ret = -EWOULDBLOCK;