From: Michal Hocko <mhocko@suse.com>
To: minyard@acm.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Corey Minyard <cminyard@mvista.com>
Subject: Re: [PATCH] oom_kill: oom_score_adj broken for processes with small memory usage
Date: Fri, 16 Jul 2021 07:19:24 +0200 [thread overview]
Message-ID: <YPEW3H+W/uiRYIfn@dhcp22.suse.cz> (raw)
In-Reply-To: <20210701125430.836308-1-minyard@acm.org>
On Thu 01-07-21 07:54:30, minyard@acm.org wrote:
> From: Corey Minyard <cminyard@mvista.com>
>
> If you have a process with less than 1000 totalpages, the calculation:
>
> adj = (long)p->signal->oom_score_adj;
> ...
> adj *= totalpages / 1000;
>
> will always result in adj being zero no matter what oom_score_adj is,
> which could result in the wrong process being picked for killing.
>
> Fix by adding 1000 to totalpages before dividing.
Yes, this is a known limitation of the oom_score_adj and its scale.
Is this a practical problem to be solved though? I mean 0-1000 pages is
not really that much different from imprecision at a larger scale where
tasks are effectively considered equal.
I have to say I do not really like the proposed workaround. It doesn't
really solve the problem yet it adds another special case.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2021-07-16 5:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-01 12:54 [PATCH] oom_kill: oom_score_adj broken for processes with small memory usage minyard
2021-07-16 5:19 ` Michal Hocko [this message]
2021-07-16 12:25 ` Corey Minyard
2021-09-02 19:55 ` Andrew Morton
2021-09-03 1:52 ` Corey Minyard
2021-09-03 7:49 ` Michal Hocko
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