#include <linux/wait.h>
#include <linux/hash.h>
-void init_waitqueue_head(wait_queue_head_t *q)
+void __init_waitqueue_head(wait_queue_head_t *q, struct lock_class_key *key)
{
spin_lock_init(&q->lock);
+ lockdep_set_class(&q->lock, key);
INIT_LIST_HEAD(&q->task_list);
}
-EXPORT_SYMBOL(init_waitqueue_head);
+EXPORT_SYMBOL(__init_waitqueue_head);
-void fastcall add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
+void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
{
unsigned long flags;
}
EXPORT_SYMBOL(add_wait_queue);
-void fastcall add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
+void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
{
unsigned long flags;
}
EXPORT_SYMBOL(add_wait_queue_exclusive);
-void fastcall remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
+void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
{
unsigned long flags;
* stops them from bleeding out - it would still allow subsequent
* loads to move into the critical region).
*/
-void fastcall
+void
prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state)
{
unsigned long flags;
spin_lock_irqsave(&q->lock, flags);
if (list_empty(&wait->task_list))
__add_wait_queue(q, wait);
- /*
- * don't alter the task state if this is just going to
- * queue an async wait queue callback
- */
- if (is_sync_wait(wait))
- set_current_state(state);
+ set_current_state(state);
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL(prepare_to_wait);
-void fastcall
+void
prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state)
{
unsigned long flags;
spin_lock_irqsave(&q->lock, flags);
if (list_empty(&wait->task_list))
__add_wait_queue_tail(q, wait);
- /*
- * don't alter the task state if this is just going to
- * queue an async wait queue callback
- */
- if (is_sync_wait(wait))
- set_current_state(state);
+ set_current_state(state);
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL(prepare_to_wait_exclusive);
-void fastcall finish_wait(wait_queue_head_t *q, wait_queue_t *wait)
+/*
+ * finish_wait - clean up after waiting in a queue
+ * @q: waitqueue waited on
+ * @wait: wait descriptor
+ *
+ * Sets current thread back to running state and removes
+ * the wait descriptor from the given waitqueue if still
+ * queued.
+ */
+void finish_wait(wait_queue_head_t *q, wait_queue_t *wait)
{
unsigned long flags;
}
EXPORT_SYMBOL(finish_wait);
+/*
+ * abort_exclusive_wait - abort exclusive waiting in a queue
+ * @q: waitqueue waited on
+ * @wait: wait descriptor
+ * @state: runstate of the waiter to be woken
+ * @key: key to identify a wait bit queue or %NULL
+ *
+ * Sets current thread back to running state and removes
+ * the wait descriptor from the given waitqueue if still
+ * queued.
+ *
+ * Wakes up the next waiter if the caller is concurrently
+ * woken up through the queue.
+ *
+ * This prevents waiter starvation where an exclusive waiter
+ * aborts and is woken up concurrently and noone wakes up
+ * the next waiter.
+ */
+void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait,
+ unsigned int mode, void *key)
+{
+ unsigned long flags;
+
+ __set_current_state(TASK_RUNNING);
+ spin_lock_irqsave(&q->lock, flags);
+ if (!list_empty(&wait->task_list))
+ list_del_init(&wait->task_list);
+ else if (waitqueue_active(q))
+ __wake_up_locked_key(q, mode, key);
+ spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL(abort_exclusive_wait);
+
int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
{
int ret = default_wake_function(wait, mode, sync, key);
* waiting, the actions of __wait_on_bit() and __wait_on_bit_lock() are
* permitted return codes. Nonzero return codes halt waiting and return.
*/
-int __sched fastcall
+int __sched
__wait_on_bit(wait_queue_head_t *wq, struct wait_bit_queue *q,
int (*action)(void *), unsigned mode)
{
}
EXPORT_SYMBOL(__wait_on_bit);
-int __sched fastcall out_of_line_wait_on_bit(void *word, int bit,
+int __sched out_of_line_wait_on_bit(void *word, int bit,
int (*action)(void *), unsigned mode)
{
wait_queue_head_t *wq = bit_waitqueue(word, bit);
}
EXPORT_SYMBOL(out_of_line_wait_on_bit);
-int __sched fastcall
+int __sched
__wait_on_bit_lock(wait_queue_head_t *wq, struct wait_bit_queue *q,
int (*action)(void *), unsigned mode)
{
- int ret = 0;
-
do {
+ int ret;
+
prepare_to_wait_exclusive(wq, &q->wait, mode);
- if (test_bit(q->key.bit_nr, q->key.flags)) {
- if ((ret = (*action)(q->key.flags)))
- break;
- }
+ if (!test_bit(q->key.bit_nr, q->key.flags))
+ continue;
+ ret = action(q->key.flags);
+ if (!ret)
+ continue;
+ abort_exclusive_wait(wq, &q->wait, mode, &q->key);
+ return ret;
} while (test_and_set_bit(q->key.bit_nr, q->key.flags));
finish_wait(wq, &q->wait);
- return ret;
+ return 0;
}
EXPORT_SYMBOL(__wait_on_bit_lock);
-int __sched fastcall out_of_line_wait_on_bit_lock(void *word, int bit,
+int __sched out_of_line_wait_on_bit_lock(void *word, int bit,
int (*action)(void *), unsigned mode)
{
wait_queue_head_t *wq = bit_waitqueue(word, bit);
}
EXPORT_SYMBOL(out_of_line_wait_on_bit_lock);
-void fastcall __wake_up_bit(wait_queue_head_t *wq, void *word, int bit)
+void __wake_up_bit(wait_queue_head_t *wq, void *word, int bit)
{
struct wait_bit_key key = __WAIT_BIT_KEY_INITIALIZER(word, bit);
if (waitqueue_active(wq))
* may need to use a less regular barrier, such fs/inode.c's smp_mb(),
* because spin_unlock() does not guarantee a memory barrier.
*/
-void fastcall wake_up_bit(void *word, int bit)
+void wake_up_bit(void *word, int bit)
{
__wake_up_bit(bit_waitqueue(word, bit), word, bit);
}
EXPORT_SYMBOL(wake_up_bit);
-fastcall wait_queue_head_t *bit_waitqueue(void *word, int bit)
+wait_queue_head_t *bit_waitqueue(void *word, int bit)
{
const int shift = BITS_PER_LONG == 32 ? 5 : 6;
const struct zone *zone = page_zone(virt_to_page(word));
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff