Re: [RFC 0/4] Replace mmap_sem by a range lock

[Matthew Wilcox]

On Wed, Apr 19, 2017 at 02:18:23PM +0200, Laurent Dufour wrote:
> Following the series pushed by Davidlohr Bueso based on the Jan Kara's
> work [1] which introduces range locks, this series implements the
> first step of the attempt to replace the mmap_sem by a range lock.

Have you previously documented attempts to replace the mmap_sem by an
existing lock type before introducing a new (and frankly weird) lock?
My initial question is "Why not use RCU for this?" -- the rxrpc code
uses an rbtree protected by RCU.