On Thu, Oct 24, 2013 at 12:25:12PM -0500, Serge Hallyn wrote: > Quoting Brian May (brian@microcomaustralia.com.au): > > On 24 October 2013 11:09, Adam Borowski <kilobyte@angband.pl> wrote: > > > * it breaks other users of cgroups. I have not tested this personally > > > (mostly because of the above point), but if I understand it right, it takes > > > over the whole cgroups system, requiring anything that runs on the same > > > kernel instance to beg it via dbus to perform required actions. > > I have heard this said before, would like to have some official > > confirmation if this is actually the case or not. cgroups are currently > > hierarchical, I would have thought this would mean, at least in theory, > > different programs could be responsible for different parts of > > the hierarchy. > It currently can't prevent you from just mounting the cgroupfs and > working with it. One of the justifications presented at plumbers for > wanting to do this was that changes to a subtree you control can > affect other tasks. But it was agreed that that was actually only > for realtime (?) cgroup and that it is a bug which must be fixed. The upshot being, AIUI, that there is a legitimate need for a single process on each system to have a complete view of the cgroups heirarchy; even if most users don't need a fine-grained policy manager, we should design with this in mind. On systems using systemd as init, the plan is for PID 1 to be the process that has this overview, and that's fine; the problem is the tight coupling of logind to systemd init for this, rather than using a standard interface that can be implemented by multiple providers of a cgroup manager service. And this is not just an issue because of people not wanting to use systemd init, but also because systemd init *can't* run in a container. So if you want any of the other users of cgroups (such as lxc) to coexist with systemd, there needs to be a common protocol for this. -- Steve Langasek Give me a lever long enough and a Free OS Debian Developer to set it on, and I can move the world. Ubuntu Developer http://www.debian.org/ slangasek@ubuntu.com vorlon@debian.org
Attachment:
signature.asc
Description: Digital signature