Re: [PATCH v3 cgroup/for-5.20] cgroup: Replace cgroup->ancestor_ids[] with ->ancestors[]

[Tejun Heo]

On Fri, Jul 29, 2022 at 01:10:16PM -1000, Tejun Heo wrote:
> Every cgroup knows all its ancestors through its ->ancestor_ids[]. There's
> no advantage to remembering the IDs instead of the pointers directly and
> this makes the array useless for finding an actual ancestor cgroup forcing
> cgroup_ancestor() to iteratively walk up the hierarchy instead. Let's
> replace cgroup->ancestor_ids[] with ->ancestors[] and remove the walking-up
> from cgroup_ancestor().
> 
> While at it, improve comments around cgroup_root->cgrp_ancestor_storage.
> 
> This patch shouldn't cause user-visible behavior differences.
> 
> v2: Update cgroup_ancestor() to use ->ancestors[].
> 
> v3: cgroup_root->cgrp_ancestor_storage's type is updated to match
>     cgroup->ancestors[]. Better comments.
> 
> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
> Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>

Applied to cgroup/for-6.1.

-- 
tejun