Re: [PATCH v6 00/71] Introducing the Maple Tree

From: Andrew Morton
Date: Wed Feb 16 2022 - 14:47:09 EST


On Tue, 15 Feb 2022 14:37:44 +0000 Liam Howlett <liam.howlett@xxxxxxxxxx> wrote:

> The maple tree is an RCU-safe range based B-tree designed to use modern
> processor cache efficiently. There are a number of places in the kernel
> that a non-overlapping range-based tree would be beneficial, especially
> one with a simple interface. The first user that is covered in this
> patch set is the vm_area_struct, where three data structures are
> replaced by the maple tree: the augmented rbtree, the vma cache, and the
> linked list of VMAs in the mm_struct. The long term goal is to reduce
> or remove the mmap_sem contention.

Has a path been chosen which gets us from here to significant reduction
in mmap_lock overhead?

If so, what's the plan and what must be done?

Thanks.