FM / user.slice

/sys/fs/cgroup/devices/user.slice

Name	Mode	Actions
cgroup.clone_children	0644	edit dl rm
cgroup.procs	0644	edit dl rm
devices.allow	0200	edit dl rm
devices.deny	0200	edit dl rm
devices.list	0444	edit dl rm
notify_on_release	0644	edit dl rm
tasks	0644	edit dl rm

Edit: /sys/fs/cgroup/devices/user.slice/notify_on_release (0B)