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-rw-r--r--kernel/locking/qspinlock.c13
1 files changed, 5 insertions, 8 deletions
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index ebe6b8ec7cb3..1df5fef8a656 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -220,21 +220,18 @@ static __always_inline void clear_pending_set_locked(struct qspinlock *lock)
*/
static __always_inline u32 xchg_tail(struct qspinlock *lock, u32 tail)
{
- u32 old, new, val = atomic_read(&lock->val);
+ u32 old, new;
- for (;;) {
- new = (val & _Q_LOCKED_PENDING_MASK) | tail;
+ old = atomic_read(&lock->val);
+ do {
+ new = (old & _Q_LOCKED_PENDING_MASK) | tail;
/*
* We can use relaxed semantics since the caller ensures that
* the MCS node is properly initialized before updating the
* tail.
*/
- old = atomic_cmpxchg_relaxed(&lock->val, val, new);
- if (old == val)
- break;
+ } while (!atomic_try_cmpxchg_relaxed(&lock->val, &old, new));
- val = old;
- }
return old;
}
#endif /* _Q_PENDING_BITS == 8 */