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

[Minchan Kim]

On Tue, May 24, 2011 at 10:53 AM, KOSAKI Motohiro
<kosaki.motohiro@xxxxxxxxxxxxxx> wrote:
>>> + Â Â Â /*
>>> + Â Â Â Â* chosen_point==1 may be a sign that root privilege bonus is too
>>> large
>>> + Â Â Â Â* and we choose wrong task. Let's recalculate oom score without
>>> the
>>> + Â Â Â Â* dubious bonus.
>>> + Â Â Â Â*/
>>> + Â Â Â if (protect_root&& Â(chosen_points == 1)) {
>>> + Â Â Â Â Â Â Â protect_root = 0;
>>> + Â Â Â Â Â Â Â goto retry;
>>> + Â Â Â }
>>
>> 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
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