On 05/30, Michal Hocko wrote:
>
> @@ -852,8 +852,7 @@ void oom_kill_process(struct oom_control *oc, struct
> task_struct *p,
> continue;
> if (same_thread_group(p, victim))
> continue;
> - if (unlikely(p->flags & PF_KTHREAD) || is_global_init(p) ||
> - p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) {
> + if (unlikely(p->flags & PF_KTHREAD) || is_global_init(p)) {
> /*
> * We cannot use oom_reaper for the mm shared by this
> * process because it wouldn't get killed and so the
> @@ -862,6 +861,11 @@ void oom_kill_process(struct oom_control *oc, struct
> task_struct *p,
> can_oom_reap = false;
> continue;
> }
> + if (p->signal->oom_score_adj == OOM_ADJUST_MIN)
> + pr_warn("%s pid=%d shares mm with oom disabled %s
> pid=%d. Seems like misconfiguration, killing anyway!"
> + " Report at [email protected]\n",
> + victim->comm, task_pid_nr(victim),
> + p->comm, task_pid_nr(p));
Oh, yes, I personally do agree ;)
perhaps the is_global_init() == T case needs a warning too? the previous changes
take care about vfork() from /sbin/init, so the only reason we can see it true
is that /sbin/init shares the memory with a memory hog... Nevermind, forget.
This is a bit off-topic, but perhaps we can also change the PF_KTHREAD check
later.
Of course we should not try to kill this kthread, but can_oom_reap can be true
in
this case. A kernel thread which does use_mm() should handle the errors
correctly
if (say) get_user() fails because we unmap the memory.
Oleg.
