[RFC v9][PATCH 12/13] Checkpoint multiple processes

[Serge E. Hallyn]

Quoting Oren Laadan (orenl at cs.columbia.edu):
> Checkpointing of multiple processes works by recording the tasks tree
> structure below a given task (usually this task is the container init).
> 
> For a given task, do a DFS scan of the tasks tree and collect them
> into an array (keeping a reference to each task). Using DFS simplifies
> the recreation of tasks either in user space or kernel space. For each
> task collected, test if it can be checkpointed, and save its pid, tgid,
> and ppid.
> 
> The actual work is divided into two passes: a first scan counts the
> tasks, then memory is allocated and a second scan fills the array.
> 
> The logic is suitable for creation of processes during restart either
> in userspace or by the kernel.
> 
> Currently we ignore threads and zombies, as well as session ids.
> 
> Signed-off-by: Oren Laadan <orenl at cs.columbia.edu>

Looks good.

Acked-by: Serge Hallyn <serue at us.ibm.com>

thanks,
-serge