Re: [PATCH 0/2] mm, oom: do not grant oom victims full memory reserves access
From: Michal Hocko
Date: Mon Aug 07 2017 - 10:53:52 EST
On Thu 27-07-17 11:03:55, Michal Hocko wrote:
> Hi,
> this is a part of a larger series I posted back in Oct last year [1]. I
> have dropped patch 3 because it was incorrect and patch 4 is not
> applicable without it.
>
> The primary reason to apply patch 1 is to remove a risk of the complete
> memory depletion by oom victims. While this is a theoretical risk right
> now there is a demand for memcg aware oom killer which might kill all
> processes inside a memcg which can be a lot of tasks. That would make
> the risk quite real.
>
> This issue is addressed by limiting access to memory reserves. We no
> longer use TIF_MEMDIE to grant the access and use tsk_is_oom_victim
> instead. See Patch 1 for more details. Patch 2 is a trivial follow up
> cleanup.
>
> I would still like to get rid of TIF_MEMDIE completely but I do not have
> time to do it now and it is not a pressing issue.
>
> [1] http://lkml.kernel.org/r/20161004090009.7974-1-mhocko@xxxxxxxxxx
Are there any more comments/questions? I will resubmit if not.
--
Michal Hocko
SUSE Labs