Re: [PATCH] mm, memcg: clear page protection when memcg oom group happens

Yafang Shao
2019-11-25T11:38:38Z

On Mon, Nov 25, 2019 at 7:08 PM Michal Hocko <mhocko@kernel.org> wrote:
>
> On Mon 25-11-19 05:14:53, Yafang Shao wrote:
> > We set memory.oom.group to make all processes in this memcg are killed by
> > OOM killer to free more pages. In this case, it doesn't make sense to
> > protect the pages with memroy.{min, low} again if they are set.
>
> I do not see why? What does group OOM killing has anything to do with
> the reclaim protection? What is the actual problem you are trying to
> solve?
>

The cgroup is treated as a indivisible workload when cgroup.oom.group
is set and OOM killer is trying to kill a prcess in this cgroup.
We set cgroup.oom.group is to guarantee the workload integrity, now
that processes ara all killed, why keeps the page cache here?

Thanks
Yafang