On 8/20/18 3:21 PM, Liu Bo wrote: > As rbtree has native support of caching leftmost node, > i.e. rb_root_cached, no need to do the caching by ourselves. This looks fine to me. I think this code was probably inherited from a similar caching trick in cfq, an predates leftmost caching being generally available in the rbtree code. I'll apply it for 4.20. -- Jens Axboe