Il 17/06/2014 00:08, Waiman Long ha scritto:
+void __pv_queue_unlock(struct qspinlock *lock) +{ + int val = atomic_read(&lock->val); + + native_queue_unlock(lock); + + if (val & _Q_LOCKED_SLOW) + ___pv_kick_head(lock); +} +Again a race can happen here between the reading and writing of the lock value. I can't think of a good way to do that without using cmpxchg.
Could you just use xchg on the locked byte? Paolo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
