Re: [RFC][PATCH 5/7] VPIDs: vpid/pid conversion in VPID enabled case

[Cedric Le Goater <clg@fr.ibm.com>]

Alexey Kuznetsov wrote:

> The question was not about openvz, it was about (container,pid) approach.
> How are you going to reap chidren without a child reaper inside container?
> If you reparent all the children to a single init in root container,
> what does wait() return? In openvz it returns global pid and child is buried
> in peace. If you do not have global pid, you cannot just return private pid.

I think the "child reaper" question is not related to the (container,pid)
approach or the vpid approach. This is another question on who is the
parent of a container and how does it behaves.

We have choosen to first follow a simple "path", complete pid isolation
being the main constraint : a container is created by exec'ing a process in
it. That first process is detached from its parent processes and becomes
child of init (already running), session leader, and process group leader.
We could eventually add a daemon to act as a init process for the container.

Now, there are other ways of seeing a container parenthood, openvz, eric,
vserver, etc. We should agree on this or find a way to have different model
cohabitate.

C.