[Devel] [PATCH] cgroups: not to iterate other namespace process inside container

[Paul Menage]

On Sun, Dec 7, 2008 at 10:52 PM, gowrishankar
<gomuthuk at linux.vnet.ibm.com> wrote:
> Once tasks are populated from system namespace inside cgroup, container
> replaces
> other namespace task with 0 while listing tasks, inside container.
> Though this is expected behaviour
> from container end, there is no use of showing unwanted 0s.
> In below patch, we check if a process is in same namespace before
> loading into pid array.
>
> Signed-off-by: Gowrishankar M <gowrishankar.m at in.ibm.com>

Looks sensible, thanks.

Acked-by: Paul Menage <menage at google.com>

Can you send it on to akpm at linuxfoundation.org?

A couple of small style issues:

- title would be better as "skip processes from other namespaces when
listing a cgroup"

- use the local variable name "pid" rather than "ret"

> Index: linux-2.6.28-rc3/kernel/cgroup.c
> ===================================================================
> --- linux-2.6.28-rc3.orig/kernel/cgroup.c    2008-12-07
> 13:23:19.000000000 -0500
> +++ linux-2.6.28-rc3/kernel/cgroup.c    2008-12-07 13:24:28.000000000 -0500
> @@ -2011,14 +2011,15 @@
>  */
>  static int pid_array_load(pid_t *pidarray, int npids, struct cgroup *cgrp)
>  {
> -    int n = 0;
> +    int n = 0, ret;
>     struct cgroup_iter it;
>     struct task_struct *tsk;
>     cgroup_iter_start(cgrp, &it);
>     while ((tsk = cgroup_iter_next(cgrp, &it))) {
>         if (unlikely(n == npids))
>             break;
> -        pidarray[n++] = task_pid_vnr(tsk);
> +        if ((ret = task_pid_vnr(tsk)) > 0)
> +            pidarray[n++] = ret;
>     }
>     cgroup_iter_end(cgrp, &it);
>     return n;
> _______________________________________________
> Containers mailing list
> Containers at lists.linux-foundation.org
> https://lists.linux-foundation.org/mailman/listinfo/containers
>
> _______________________________________________
> Devel mailing list
> Devel at openvz.org
> https://openvz.org/mailman/listinfo/devel
>
_______________________________________________
Containers mailing list
Containers at lists.linux-foundation.org
https://lists.linux-foundation.org/mailman/listinfo/containers