systemd (in the sense of pid 1) doesn't do that. I. e. if you boot with init=/bin/systemd the only cgroup controller it puts tasks into (by default) is the "systemd" one, for that very reason. But if you boot with upstart (Ubuntu's default still), cgmanager creates cgroups. cgmanager puts tasks into *all* controllers (including "cpu"); as far as I know, this is so that user LXC containers work. So from cgmanager's POV this might be a design decision which can't otherwise be accomplished with the current kernel, but I'll let the cgmanager maintainers decide about whether this is a "wontfix" or whether there is a more elegant way to make user containers work.
** Summary changed: - Systemd mounts cgroups unconditionally which causes undesired effects with cpu hotplug + mounts cgroups unconditionally which causes undesired effects with cpu hotplug ** Package changed: systemd (Ubuntu) => cgmanager (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to cgmanager in Ubuntu. https://bugs.launchpad.net/bugs/1392176 Title: mounts cgroups unconditionally which causes undesired effects with cpu hotplug To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cgmanager/+bug/1392176/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
