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Date:   Mon, 23 Jul 2018 13:33:19 -0700 (PDT)
From:   David Rientjes <rientjes@google.com>
To:     Roman Gushchin <guro@fb.com>
cc:     Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@kernel.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Tejun Heo <tj@kernel.org>, cgroups@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [patch v3 -mm 3/6] mm, memcg: add hierarchical usage oom
 policy
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On Mon, 16 Jul 2018, David Rientjes wrote:

> > And "tree" is different. It actually changes how the selection algorithm works,
> > and sub-tree settings do matter in this case.
> > 
> 
> "Tree" is considering the entity as a single indivisible memory consumer, 
> it is compared with siblings based on its hierarhical usage.  It has 
> cgroup oom policy.
> 
> It would be possible to separate this out, if you'd prefer, to account 
> an intermediate cgroup as the largest descendant or the sum of all 
> descendants.  I hadn't found a usecase for that, however, but it doesn't 
> mean there isn't one.  If you'd like, I can introduce another tunable.
> 

Roman, I'm trying to make progress so that the cgroup aware oom killer is 
in a state that it can be merged.  Would you prefer a second tunable here 
to specify a cgroup's points includes memory from its subtree?

It would be helpful if you would also review the rest of the patchset.