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

From: Laurent Dufour
Date: Thu Apr 20 2017 - 10:39:47 EST


On 20/04/2017 15:33, Matthew Wilcox wrote:
> 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?

No :/

> My initial question is "Why not use RCU for this?" -- the rxrpc code
> uses an rbtree protected by RCU.

I'm also working on forward-porting work done by Peter Zijlstra :

https://marc.info/?l=linux-mm&m=141384492326748

I'll send a series on top 4.10 soon.