[systemd-devel] Systemd and cgroup management (and libcgroup)
bsingharora at gmail.com
Mon Oct 31 16:52:55 PDT 2011
On Tue, Nov 1, 2011 at 3:02 AM, Lennart Poettering
<lennart at poettering.net> wrote:
> On Mon, 31.10.11 14:43, Jan Safranek (jsafrane at redhat.com) wrote:
>> >> Even if there is, then it looks like systemd is better place to manage
>> >> it as it already is setting up the whole system and top level hierarchies.
>> >> Thanks to Jason for the suggestion.
>> Systemd pretty much covers most of the use cases. The main reason to
>> keep separate cgconfig is mounting several controllers together in one
>> hierarchy - AFAIK systemd won't support this mounting. Still, systemd
>> will happily put services to cgroups there.
> We actually do support mounting hierarchies jointly these days. Use
> "JoinControllers=" to achieve that. By default we moint and cpu and
> cpuacct together.
cool! Is it possible to UnJoinControllers at runtime and ask for a
different binding without a reboot?
>> Lennart wrote once on previous discussion :
>> systemd will create automatic groups for users and services, but will
>> not help you to set up any more complex hierarchy then just 1:1 service
>> to cgroup mappings.
>> As soon as you want a more complex tree, with multiple levels or
>> something like this you will need something like cgconfig which allows
>> you to create any tree you want.
>> Question is, if we really need complex cgroup hierarchies and/or
>> multiple controllers in a hierarchy.
> I am quite sure that sooner or later some folks will need complex cgroup
> hierarchies, for example if they want to give a group "teachers" a more
> resources than the group "students" or so. I am very sure that some
> people want features like that, but I am also quite sure I don't want to
> cover that in systemd, which is why I am happy if cgconfig could fill in
> that void. I think systemd will cover 90% of the use cases, but the 10%
> that are left are valid too, and cgconfig sounds like a useful tool to
> make that work.
Yes, I agree. I wonder if using two tools hurts user experience, but
using two configurations is quite specialized and if we have it well
documented, we should be good
More information about the systemd-devel