[CRIU] [PATCH 1/2] Re-create cgroups if necessary

[Pavel Emelyanov]

On 06/25/2014 07:28 PM, Filipe Brandenburger wrote:
> Hi,
> 
> On Wed, Jun 25, 2014 at 8:21 AM, Pavel Emelyanov <xemul at parallels.com> wrote:
>> First, on dump all cgroup paths are dumped relative to root task groups.
>> It's not so yet, but since we in -rc we can change that. Next, on restore
>> we tell the --cgroup-root $path option that would prepend $path to all
>> cgroup paths from the image.
> 
> Do we need to consider the case where children tasks are actually in
> *sibling* cgroups?
> 
> Maybe it would make sense to map cgroup names into tags in dump and
> restore just like the ext-mount support does...

It's already "tagged". If you look at how task cgroups are dumped, each
task has a 32-bit value called "cg_set", which corresponds to the
cgroup's image object called cg_set_entry.

If we could modify images in effective manner of provide the paths
modification rules to criu this would just work, I suppose.

> I'm really wondering if it wouldn't be easier to handle the cgroup
> hierarchy through external plug-ins, considering each container
> solution seems to have their own idea of how to manage cgroups.

Thanks,
Pavel