Re: [PATCH v7 1/2] cgroup: track the effective css in each cgroup

[Tejun Heo]

On Tue, Sep 29, 2026 at 04:24:10PM -0700, Peng Yu wrote:
> cgroup_e_css() and cgroup_get_e_css() find the effective css by walking
> up the hierarchy until they reach a cgroup that has the subsystem
> enabled. Per-I/O users such as nvmet need this lookup to be O(1).
>
> Track the effective css in each cgroup and make cgroup_e_css() and
> cgroup_get_e_css() use it. When a css is brought online or offline,
> update the effective css of its cgroup and of all descendants.

Applied to cgroup/for-7.4 with the subject capitalized.

Thanks.

--
tejun