Hello, Michael. Sorry about the delay. On Thu, Oct 04, 2018 at 09:40:57PM +0200, Michael Kerrisk (man-pages) wrote: > This seems odd. x/y is now of "domain invalid" type with a controller > enabled! This feels like a violation of the rules, since we can't > in other circumstances do anything with a "domain invalid" cgroup > except convert it to "threaded". In particular, we can't create > child cgroups under a "domain invalid" cgroup, or add member processes > to the cgroup, or *enable controllers in the cgroup*. In fact, when > doing the > > # echo threaded > x/z/cgroup.type > > I had expected a write(2) error because the state of x/y should > (I thought) not be permitted. So, both the interim (before turning x/z into threaded) and final (after) are completely fine - the cgroups are empty and whether threaded controllers like pids are enabled or not don't really change things that much. Maybe it is a bit inconsistent to then deny enabling threaded controllers on invalid domain cgroups. We can lift that restriction but I personally can't see why that'd be clearly better. Thanks. -- tejun
