Messages in this thread | | | Date | Wed, 29 Mar 2017 11:44:13 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/5] locking: Introduce range reader/writer lock |
| |
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) {
for (node = interval_tree_iter_first(); node; node = interval_tree_iter_next()) {
Or some interval_tree_for_each helper?
> + struct range_rwlock *blocked_lock; > + blocked_lock = range_entry(node, struct range_rwlock, node); > + > + if (!blocked_lock->reader) > + lock->blocking_ranges++;
Can this @blocked range now go EINTR and remove itself from wait_for_ranges()? If so, who will decrement our 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); > +}
| |