Re: [Libcg-devel] Systemd and cgroup management (and libcgroup)

[Lennart P. <le...@po...>]

On Tue, 01.11.11 05:55, Balbir Singh (bsi...@gm...) wrote:

> 
> On Tue, Nov 1, 2011 at 5:41 AM, Lennart Poettering
> <le...@po...> wrote:
> > On Tue, 01.11.11 05:22, Balbir Singh (bsi...@gm...) wrote:
> >
> >> cool! Is it possible to UnJoinControllers at runtime and ask for a
> >> different binding without a reboot?
> >
> > Right now you need to reboot. Joining/separating controllers at runtime
> > is really hard though, given that the hierarchies might be populated and
> > one would have to come up with a "merge" algorithm for two hierarchies
> > then.
> 
> In cgconfig/cgclear we move all the tasks to root "/" and then unmount
> the controller. The user is free to change bindings after that. It
> implies we lose resource bindings and any classification we've done.
> Given systemd's design is it possible to notify all tasks of any such
> movement and move them or is too intrusive?

Well, we could just reapply all settings we that have been configured in
systemd's config in this case.

But tbh I think requiring a reboot for a major global config change like
this is something we can probably live with. It's not that this is a
very common thing to do. Or in other words: let's wait until we get bug
reports/feature requests for this and then rethink this. The essence is
after all that doing the merging is certainly possible, just not trivial.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.