On 5/21/18 8:49 PM, Ming Lei wrote: > On Mon, May 21, 2018 at 05:11:31PM -0600, Keith Busch wrote: >> This patch simplifies the timeout handling by relying on the request >> reference counting to ensure the iterator is operating on an inflight > > The reference counting isn't free, what is the real benefit in this way? Neither is the current scheme and locking, and this is a hell of a lot simpler. I'd get rid of the kref stuff and just do a simple atomic_dec_and_test(). Most of the time we should be uncontended on that, which would make it pretty darn cheap. I'd be surprised if it wasn't better than the current alternatives. -- Jens Axboe