The "noop" elevator - quick and noisy

• The simplest elevator is the noop elevator.
• noop does not re-order I/O requests - first-come, first-sent.
• noop still may merge I/O requests if it happened to have several together in the queue when it scanned the queue.
• noop is relevant when we have a better elevator inside the storage device (e.g. RAID, NCQ, SSD...)

Originally written by guy keren