diff options
Diffstat (limited to 'kernel/locking/qspinlock.c')
| -rw-r--r-- | kernel/locking/qspinlock.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c index 956a12983bd0..46813185957b 100644 --- a/kernel/locking/qspinlock.c +++ b/kernel/locking/qspinlock.c @@ -467,16 +467,15 @@ locked: * Otherwise, we only need to grab the lock. */ - /* In the PV case we might already have _Q_LOCKED_VAL set */ - if ((val & _Q_TAIL_MASK) == tail) { - /* - * The atomic_cond_read_acquire() call above has provided the - * necessary acquire semantics required for locking. - */ - old = atomic_cmpxchg_relaxed(&lock->val, val, _Q_LOCKED_VAL); - if (old == val) - goto release; /* No contention */ - } + /* + * In the PV case we might already have _Q_LOCKED_VAL set. + * + * The atomic_cond_read_acquire() call above has provided the + * necessary acquire semantics required for locking. + */ + if (((val & _Q_TAIL_MASK) == tail) && + atomic_try_cmpxchg_relaxed(&lock->val, &val, _Q_LOCKED_VAL)) + goto release; /* No contention */ /* Either somebody is queued behind us or _Q_PENDING_VAL is set */ set_locked(lock); |