On 04/17/2014 11:58 AM, Peter Zijlstra wrote:
On Thu, Apr 17, 2014 at 11:03:57AM -0400, Waiman Long wrote:+static __always_inline void +clear_pending_set_locked(struct qspinlock *lock, u32 val) +{ + struct __qspinlock *l = (void *)lock; + + ACCESS_ONCE(l->locked_pending) = 1; +} @@ -157,8 +251,13 @@ static inline int trylock_pending(struct qspinlock *lock, u32 *pval) * we're pending, wait for the owner to go away. * * *,1,1 -> *,1,0 + * + * this wait loop must be a load-acquire such that we match the + * store-release that clears the locked bit and create lock + * sequentiality; this because not all try_clear_pending_set_locked() + * implementations imply full barriers.You renamed the function referred in the above comment.
Sorry, will fix the comments. -Longman -- 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/
