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