On Wed, 29 Mar 2017, Peter Zijlstra wrote:
On Mon, Mar 06, 2017 at 09:03:26PM -0800, Davidlohr Bueso wrote:+static __always_inline int +__range_read_lock_common(struct range_rwlock_tree *tree, + struct range_rwlock *lock, long state) +{ + struct interval_tree_node *node; + unsigned long flags; + + spin_lock_irqsave(&tree->lock, flags); + lock->reader = true; + + if (!__range_intersects_intree(tree, lock)) + goto insert; + + node = interval_tree_iter_first(&tree->root, lock->node.start, + lock->node.last); + while (node) { + struct range_rwlock *blocked_lock; + blocked_lock = range_entry(node, struct range_rwlock, node); + + if (!blocked_lock->reader) + lock->blocking_ranges++; + node = interval_tree_iter_next(node, lock->node.start, + lock->node.last); + } +insert: + __range_tree_insert(tree, lock); + + lock->task = current; + spin_unlock_irqrestore(&tree->lock, flags); + + return wait_for_ranges(tree, lock, state); +}Another thing; this implementation lacks lockdep annotations and has 0 other debugging features.
True.
Is there something that makes the normal rwsem lockdep annotation not work for this?
Not that I know of. Let me look into it.
