IMO "lookups based on any address in the interval" requires "traversal in sorted order", although I could have probably been more precise in my terms. I would

IMO "lookups based on any address in the interval" requires "traversal in sorted order", although I could have probably been more precise in my terms. I would be curious if anyone has ever profiled the impact of changing mm_rb to a B-tree. It might be very difficult if existing code that uses mm_rb depends on pointer stability, though.