Re: [PATCH 4/5] oom: don't kill random process

Minchan Kim
2011-05-24T08:46:56Z

On Tue, May 24, 2011 at 10:53 AM, KOSAKI Motohiro
<kosaki.motohiro@jp.fujitsu.com> wrote:
>>> +       /*
>>> +        * chosen_point==1 may be a sign that root privilege bonus is too
>>> large
>>> +        * and we choose wrong task. Let's recalculate oom score without
>>> the
>>> +        * dubious bonus.
>>> +        */
>>> +       if (protect_root&&  (chosen_points == 1)) {
>>> +               protect_root = 0;
>>> +               goto retry;
>>> +       }
>>
>> The idea is good to me.
>> But once we meet it, should we give up protecting root privileged
>> processes?
>> How about decaying bonus point?
>
> After applying my patch, unprivileged process never get score-1. (note,
> mapping
> anon pages naturally makes to increase nr_ptes)

Hmm, If I understand your code correctly, unprivileged process can get
a score 1 by 3% bonus.
So after all, we can get a chosen_point with 1.
Why I get a chosen_point with 1 is as bonus is rather big, I think.
So I would like to use small bonus than first iteration(ie, decay bonus).

>
> Then, decaying don't make any accuracy. Am I missing something?

Maybe I miss something. :(

--
Kind regards,
Minchan Kim