On Mon, May 15, 2017 at 02:07:21AM -0700, Davidlohr Bueso wrote:
> +static inline int wait_for_ranges(struct range_lock_tree *tree,
> + struct range_lock *lock, long state)
> +{
> + int ret = 0;
> +
> + while (true) {
> + set_current_state(state);
> +
> + /* do we need to go to sleep? */
> + if (!lock->blocking_ranges)
> + break;
> +
> + if (unlikely(signal_pending_state(state, current))) {
> + struct interval_tree_node *node;
> + unsigned long flags;
> + DEFINE_WAKE_Q(wake_q);
> +
> + ret = -EINTR;
> + /*
> + * We're not taking the lock after all, cleanup
> + * after ourselves.
> + */
> + spin_lock_irqsave(&tree->lock, flags);
> +
> + range_lock_clear_reader(lock);
> + __range_tree_remove(tree, lock);
> +
> + if (!__range_intersects_intree(tree, lock))
> + goto unlock;
> +
> + range_interval_tree_foreach(node, &tree->root,
> + lock->node.start,
> + lock->node.last) {
> + struct range_lock *blked;
> + blked = to_range_lock(node);
> +
> + if (range_lock_is_reader(lock) &&
> + range_lock_is_reader(blked))
> + continue;
> +
> + /* unaccount for threads _we_ are blocking */
> + if (lock->seqnum < blked->seqnum)
> + range_lock_put(blked, &wake_q);
> + }
> +
> + unlock:
> + spin_unlock_irqrestore(&tree->lock, flags);
> + wake_up_q(&wake_q);
> + break;
> + }
> +
> + schedule();
> + }
> +
> + __set_current_state(TASK_RUNNING);
> + return ret;
> +}
> +void range_read_unlock(struct range_lock_tree *tree, struct range_lock *lock)
> +{
> + struct interval_tree_node *node;
> + unsigned long flags;
> + DEFINE_WAKE_Q(wake_q);
> +
> + spin_lock_irqsave(&tree->lock, flags);
> +
> + range_lock_clear_reader(lock);
> + __range_tree_remove(tree, lock);
> +
> + range_lock_release(&tree->dep_map, 1, _RET_IP_);
> +
> + if (!__range_intersects_intree(tree, lock)) {
> + /* nobody to wakeup, we're done */
> + spin_unlock_irqrestore(&tree->lock, flags);
> + return;
> + }
> +
> + range_interval_tree_foreach(node, &tree->root,
> + lock->node.start, lock->node.last) {
> + struct range_lock *blocked_lock;
> + blocked_lock = to_range_lock(node);
> +
> + if (!range_lock_is_reader(blocked_lock))
> + range_lock_put(blocked_lock, &wake_q);
> + }
> +
> + spin_unlock_irqrestore(&tree->lock, flags);
> + wake_up_q(&wake_q);
> +}
> +EXPORT_SYMBOL_GPL(range_read_unlock);
> +void range_write_unlock(struct range_lock_tree *tree, struct range_lock
> *lock)
> +{
> + struct interval_tree_node *node;
> + unsigned long flags;
> + DEFINE_WAKE_Q(wake_q);
> +
> + spin_lock_irqsave(&tree->lock, flags);
> +
> + range_lock_clear_reader(lock);
> + __range_tree_remove(tree, lock);
> +
> + range_lock_release(&tree->dep_map, 1, _RET_IP_);
> +
> + if (!__range_intersects_intree(tree, lock)) {
> + /* nobody to wakeup, we're done */
> + spin_unlock_irqrestore(&tree->lock, flags);
> + return;
> + }
> +
> + range_interval_tree_foreach(node, &tree->root,
> + lock->node.start, lock->node.last) {
> + struct range_lock *blocked_lock;
> + blocked_lock = to_range_lock(node);
> +
> + range_lock_put(blocked_lock, &wake_q);
> + }
> +
> + spin_unlock_irqrestore(&tree->lock, flags);
> + wake_up_q(&wake_q);
> +}
> +EXPORT_SYMBOL_GPL(range_write_unlock);
There is significant duplication here. Can't we have a
__range_unlock_common() and use that 3 times?
