On Sat, Nov 09 2002, Andrew Morton wrote:
> And Jens's rbtree-based insertion code for the request queue.  Which
> means that the queues can be grown a *lot* if people want to play with
> that.  The VM should be able to cope with it fine.

I've attached a small document describing the deadline io scheduler
tunables. stream_unit is not in Andrew's version, yet, it uses a hard
defined 128KiB. Also, Andrew didn't apply the rbtree patch only the
tunable patch. So it uses the same insertion algorithm as the default
kernel, two linked lists.

-- 
Jens Axboe