Re: [QUESTION] about the maple tree and current status of mmap_lock scalability

Suren Baghdasaryan
2022-12-29T17:22:15Z

On Thu, Dec 29, 2022 at 9:10 AM Lorenzo Stoakes <lstoakes@gmail.com> wrote:
>
> On Thu, Dec 29, 2022 at 04:51:37PM +0000, Matthew Wilcox wrote:
> > The mmap_lock is taken for many, many things. [snip]
>
> I am currently describing the use of this lock (for 6.0) in the book and it is
> striking just how broadly it's used. I'm diagramming it out for 'core' users,
> i.e. non-driver and non-some other things, but even constraining that leaves a
> HUGE number of users. I've also documented the 'unexpected' uses of the
> page_table_lock, which seems to have been significantly improved over time but
> still a few cases remain!
>
> Am happy to give you (+ anybody else on MAINTAINERS list) an early copy of the
> relevant bit (once I've finished the diagrams anyway) if that'd be helpful!

Yes please, that would be interesting.

>
> Now if you guys could stop obsoleting my work that'd be great ;)