On 12/13/2011 01:31 PM, Lennart Poettering wrote: > On Tue, 13.12.11 13:06, Jan Safranek (jsafr...@redhat.com) wrote: > >> >> On 12/13/2011 12:46 PM, Lennart Poettering wrote: >>> On Fri, 09.12.11 15:32, Jan Safranek (jsafr...@redhat.com) wrote: >> >> <snip> >> >>> Note that this will set up the cgroup structure only during late boot, >>> which should be fine for most cases. However, in some cases it might >>> make sense to initialize this due to early boot (for example, to handle >>> early-boot service, like udev).if you care for those add lines like >>> the following: >>> >>> DefaultDependencies=no >>> Conflicts=shutdown.target >>> Before=basic.target shutdown.target >> >> I expect that the services that needs cgroups would have >> "After=cgconfig.service" and systemd will start cgconfig before any of >> them, regardless how early in the boot it is. In the end I might not >> need any After/Before in cgconfig.conf at all. Of course, admin must add >> this "After=cgconfig.service" manually to all dependent services, but he >> already needs to add "ControlGroup=..." there. > > Well, this is mostly what happens, except that early boot services are > a bit special. > > i.e. normal services are implicitly ordered after basic.target. An early > boot service is not, and even usually ordered before > basic.target. Therefore, if your service cgconfig.service is not marked > as early boot service it will be ordered after basic.target, and hence > we'd have an ordering loop against an early boot service, if it wants to > be started after cgconfig.service... > > But maybe it's not worth thinking about this too much, since early boot > services are special anyway, and we can still think about this if > there's actaully somebody who wants to move an early boot service into > an arbitrary cgroup. > >> I would end up with this simple service in the end: >> >> [Unit] >> DefaultDependencies=no >> >> [Service] >> Type=oneshot >> RemainAfterExit=yes >> ExecStart=/sbin/cgconfigparser -l /etc/cgconfig.conf -s 1664 >> ExecStop=/sbin/cgclear -l /etc/cgconfig.conf -e >> >> [Install] >> WantedBy=sysinit.target >> >> Could this work? > > I'd recommend adding this too: > > Conflicts=shutdown.target > Before=basic.target shutdown.target > > Otherwise we'd not invoke the stop binary on shutdown. And the > Before=basic.target ensures that the cgroup tree is fully set up before > normal services are started, which might not be necessary, but might > still make sense?
Agreed, I'll add Conflicts/Before as you suggest. On my fedora 16 I am able to put udev to a control group this way. Thanks for your help! Jan ------------------------------------------------------------------------------ Cloud Computing - Latest Buzzword or a Glimpse of the Future? This paper surveys cloud computing today: What are the benefits? Why are businesses embracing it? What are its payoffs and pitfalls? http://www.accelacomm.com/jaw/sdnl/114/51425149/ _______________________________________________ Libcg-devel mailing list Libcg-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libcg-devel
