cgroup: Replace cgroup->ancestor_ids[] with ->ancestors[]

Browse source

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@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>

...

This commit is contained in:

Tejun Heo 2022-07-29 13:10:16 -10:00

parent 568035b01c

commit 7f203bc89e

5 changed files with 22 additions and 20 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

16

include/linux/cgroup-defs.h

View file

8

include/linux/cgroup.h

View file