Subject: Re: 4.8.8 kernel trigger OOM killer repeatedly when I have lots of
 RAM that should be free
To: Marc MERLIN <marc@merlins.org>
References: <20161121154336.GD19750@merlins.org>
 <0d4939f3-869d-6fb8-0914-5f74172f8519@suse.cz>
 <20161121215639.GF13371@merlins.org>
 <20161122160629.uzt2u6m75ash4ved@merlins.org>
Cc: linux-mm@kvack.org, Michal Hocko <mhocko@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>, Tejun Heo <tj@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Vlastimil Babka <vbabka@suse.cz>
Message-ID: <48061a22-0203-de54-5a44-89773bff1e63@suse.cz>
Date: Tue, 22 Nov 2016 17:14:02 +0100
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On 11/22/2016 05:06 PM, Marc MERLIN wrote:
> On Mon, Nov 21, 2016 at 01:56:39PM -0800, Marc MERLIN wrote:
>> On Mon, Nov 21, 2016 at 10:50:20PM +0100, Vlastimil Babka wrote:
>>>> 4.9rc5 however seems to be doing better, and is still running after 18
>>>> hours. However, I got a few page allocation failures as per below, but the
>>>> system seems to recover.
>>>> Vlastimil, do you want me to continue the copy on 4.9 (may take 3-5 days) 
>>>> or is that good enough, and i should go back to 4.8.8 with that patch applied?
>>>> https://marc.info/?l=linux-mm&m=147423605024993
>>>
>>> Hi, I think it's enough for 4.9 for now and I would appreciate trying
>>> 4.8 with that patch, yeah.
>>
>> So the good news is that it's been running for almost 5H and so far so good.
> 
> And the better news is that the copy is still going strong, 4.4TB and
> going. So 4.8.8 is fixed with that one single patch as far as I'm
> concerned.
> 
> So thanks for that, looks good to me to merge.

Thanks a lot for the testing. So what do we do now about 4.8? (4.7 is
already EOL AFAICS).

- send the patch [1] as 4.8-only stable. Greg won't like that, I expect.
  - alternatively a simpler (againm 4.8-only) patch that just outright
prevents OOM for 0 < order < costly, as Michal already suggested.
- backport 10+ compaction patches to 4.8 stable
- something else?

Michal? Linus?

[1] https://marc.info/?l=linux-mm&m=147423605024993

> Marc
>