Re: [patch 1/5] oom: don't kill unkillable children or siblings

Andrew Morton
2006-10-12T22:00:58Z

On Thu, 12 Oct 2006 16:09:43 +0200 (CEST)
Nick Piggin <npiggin@suse.de> wrote:

> Abort the kill if any of our threads have OOM_DISABLE set. Having this test
> here also prevents any OOM_DISABLE child of the "selected" process from being
> killed.
>
> Signed-off-by: Nick Piggin <npiggin@suse.de>
>
> Index: linux-2.6/mm/oom_kill.c
> ===================================================================
> --- linux-2.6.orig/mm/oom_kill.c
> +++ linux-2.6/mm/oom_kill.c
> @@ -312,15 +312,24 @@ static int oom_kill_task(struct task_str
> if (mm == NULL)
> return 1;
>
> + /*
> + * Don't kill the process if any threads are set to OOM_DISABLE
> + */
> + do_each_thread(g, q) {
> + if (q->mm == mm && p->oomkilladj == OOM_DISABLE)
> + return 1;
> + } while_each_thread(g, q);
> +
> __oom_kill_task(p, message);
> +
> /*
> * kill all processes that share the ->mm (i.e. all threads),
> * but are in a different thread group
> */
> - do_each_thread(g, q)
> + do_each_thread(g, q) {
> if (q->mm == mm && q->tgid != p->tgid)
> __oom_kill_task(q, message);
> - while_each_thread(g, q);
> + } while_each_thread(g, q);
>
> return 0;

One wonders whether OOM_DISABLE should be a property of the mm_struct, not
of the task_struct.