* node before publication.
*/
- rcu_read_lock();
for (;;) {
- struct rcu_lfq_node *tail = rcu_dereference(q->tail);
- struct rcu_lfq_node *next;
+ struct rcu_lfq_node *tail, *next;
+ rcu_read_lock();
+ tail = rcu_dereference(q->tail);
/*
- * Typically expect tail to be NULL.
+ * Typically expect tail->next to be NULL.
*/
next = uatomic_cmpxchg(&tail->next, NULL, node);
if (next == NULL) {
* further and retry.
*/
uatomic_cmpxchg(&q->tail, tail, next);
+ rcu_read_unlock();
continue;
}
}
* which calls the release primitive when the reference count drops to zero. A
* grace period must be waited before performing the actual memory reclamation
* in the release primitive.
- * The entry lfq node returned by dequeue must no be re-used before the
+ * The entry lfq node returned by dequeue must not be re-used before the
* reference count reaches zero.
*/
struct rcu_lfq_node *
rcu_lfq_dequeue(struct rcu_lfq_queue *q, void (*release)(struct urcu_ref *))
{
- rcu_read_lock();
for (;;) {
- struct rcu_lfq_node *head = rcu_dereference(q->head);
- struct rcu_lfq_node *next = rcu_dereference(head->next);
+ struct rcu_lfq_node *head, *next;
+ rcu_read_lock();
+ head = rcu_dereference(q->head);
+ next = rcu_dereference(head->next);
if (next) {
if (uatomic_cmpxchg(&q->head, head, next) == head) {
rcu_read_unlock();
return next;
} else {
/* Concurrently pushed, retry */
+ rcu_read_unlock();
continue;
}
} else {