Re: [PATCH v2] cgroup: Make rebind_subsystems() disable v2 controllers all at once

[Tejun Heo]

On Sat, Sep 18, 2021 at 06:53:08PM -0400, Waiman Long wrote:
...
> It was caused by the fact that rebind_subsystem() disables
> controllers to be rebound one by one. If more than one disabled
> controllers are originally from the default hierarchy, it means that
> cgroup_apply_control_disable() will be called multiple times for the
> same default hierarchy. A controller may be killed by css_kill() in
> the first round. In the second round, the killed controller may not be
> completely dead yet leading to the warning.
> 
> To avoid this problem, we collect all the ssid's of controllers that
> needed to be disabled from the default hierarchy and then disable them
> in one go instead of one by one.
> 
> Fixes: 334c3679ec4b ("cgroup: reimplement rebind_subsystems() using cgroup_apply_control() and friends")
> Signed-off-by: Waiman Long <longman@xxxxxxxxxx>

Applied to cgroup/for-5.16.

Thanks.

-- 
tejun