On 03/02/2014 09:10 AM, Oleg Nesterov wrote:
On 02/26, Waiman Long wrote:+#define _ARCH_SUPPORTS_ATOMIC_8_16_BITS_OPS + +/* + * x86-64 specific queue spinlock union structure + */ +union arch_qspinlock { + struct qspinlock slock; + u8 lock; /* Lock bit */ +};And this enables the optimized version of queue_spin_setlock(). But why does it check ACCESS_ONCE(qlock->lock) == 0 ? This is called right after queue_get_lock_qcode() returns 0, this locked should be likely unlocked. Oleg.
Yes, the read check in queue_spin_setlock is probably redundant. Will remove that.
-Longman _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
