[Devel] [RFC][PATCH] Add child reaper to struct pspace

[Kirill Korotaev]

Sukadev Bhattiprolu wrote:
> Cedric Le Goater [clg at fr.ibm.com] wrote:
> | 
> | <snip>
> | 
> | >   */
> | >  static void
> | >  forget_original_parent(struct task_struct *father, struct list_head *to_release)
> | > @@ -669,7 +670,7 @@ forget_original_parent(struct task_struc
> | >  	do {
> | >  		reaper = next_thread(reaper);
> | >  		if (reaper == father) {
> | > -			reaper = child_reaper;
> | > +			reaper = father->pspace->child_reaper;
> | >  			break;
> | >  		}
> | >  	} while (reaper->exit_state);
> | > @@ -857,7 +858,7 @@ fastcall NORET_TYPE void do_exit(long co
> | 
> | what about killing all the task in that pid space if child_reaper == init
> | dies ?
> | 
> 
> We probably need that for instance when a process in the parent pspace 
> kills the init of a child pspace, we should destroy the child pspace
> by killing all the tasks in the child pspace including the child reaper.
exactly. the situation you described is how we do handle it.
you can check do_initproc_exit() function in OpenVZ
to check how it can be done and probably save some of your time.
(http://git.openvz.org/?p=linux-2.6-openvz;a=summary)

> I guess we need to maintain a list of task_structs in the pspace and walk
> that list. Will work on that as a separate patch.
wait. we either need to have a list of _pids_ or it
should be called task_namespace, not pid, since we are adding more 
code related to tasks.

Kirill