static inline void arch_spin_unlock_wait(arch_spinlock_t *lock)
{
- while (arch_spin_is_locked(lock))
+ __ticket_t head = ACCESS_ONCE(lock->tickets.head);
+
+ for (;;) {
+ struct __raw_tickets tmp = ACCESS_ONCE(lock->tickets);
+ /*
+ * We need to check "unlocked" in a loop, tmp.head == head
+ * can be false positive because of overflow.
+ */
+ if (tmp.head == (tmp.tail & ~TICKET_SLOWPATH_FLAG) ||
+ tmp.head != head)
+ break;
+
cpu_relax();
+ }
}
/*