Re: [PATCH -next v3 0/9] rbtree: Cache leftmost node internally

Peter Zijlstra
2017-07-05T17:49:24Z

On Thu, Jun 29, 2017 at 10:15:44AM -0700, Davidlohr Bueso wrote:

> Here's a proposal for extending rbtrees to internally cache the leftmost
> node such that we can have fast overlap check optimization for all interval
> tree users[1]. The benefits of this series are that:
>
> (i) Unify users that do internal leftmost node caching.
> (ii) Optimize all interval tree users.
> (iii) Convert at least two new users (epoll and procfs) to the new interface.
>
> Patch 1: Layout the rb machinery.
>
> Patches 2-5: Make use of the internal leftmost node in scheduler and
> rt mutexes and cfq.
>
> Patch 6: Implements fast overlap checks for interval trees.
>
> Patch 7: rocket science.
>
> Patches 8,9: New patches that convert to O(1) rb_first_cached().
>
> The series has survived booting, kernel builds and pistress workloads.
>
> Ingo, I know it's late in the game, but could it be considered for
> v4.13? Given that v2 has been there a while and there are no issues
> currently. Applies on top of today's -next.

IIRC akpm typically collects rb-tree patches.

In any case:

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>