On Di, 13.02.18 17:06, Josh Snyder (jo...@netflix.com) wrote: > I've tested against both legacy and unified cgroup hierarchies. The > functionality to detect the current cgroups and nest processes underneath them > appears to be in manager_setup_cgroup (src/core/cgroup.c:2033). My question > for > the list is what motivated adding this awesome feature to systemd in the first > place, and (more importantly to me) is it likely to continue to exist in the > future?
This logic exists for two reasons: 1. "systemd --user" needs this so that it can manage the cgroup subtree it is started in. It gets a delegated, unprivileged cgroup subtree and couldn't even run outside of its subtree, even if it wanted to. 2. Before cgroup namespaces existed this kind of behaviour was necessary to make sure systemd run inside containers works correctly: it would only make use of its subtree, and leave alone the rest. And besides that, cgroups is supposed to be neatly composable, hence it's philosophically really the right thing to do. And yes, we'll continue to support that. That all said, I think we should really try to make systemd work with your usecase directly and natively, i.e. add enough flexibility to systemd so that you don't have to wrap it in such a "foreign" prefix cgroup to do what you want... For example, if PID 1 knew a "DefaultSlice=" option in /etc/systemd/system.conf, and logind/machined knew similar options in their respective configuration files you could do what you are trying to do without leaving systemd territory relatively easily. Just set those options to some slice further down thre tree, and you could leave machined run inside of systemd just fine without having to arrange anything outside of it... Lennart -- Lennart Poettering, Red Hat _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
