Re: [patch -mm v2 2/3] mm, memcg: replace cgroup aware oom killer mount option with tunable

[Andrew Morton]

On Thu, 25 Jan 2018 15:53:48 -0800 (PST) David Rientjes <rientjes@xxxxxxxxxx> wrote:

> Now that each mem cgroup on the system has a memory.oom_policy tunable to
> specify oom kill selection behavior, remove the needless "groupoom" mount
> option that requires (1) the entire system to be forced, perhaps
> unnecessarily, perhaps unexpectedly, into a single oom policy that
> differs from the traditional per process selection, and (2) a remount to
> change.
> 
> Instead of enabling the cgroup aware oom killer with the "groupoom" mount
> option, set the mem cgroup subtree's memory.oom_policy to "cgroup".

Can we retain the groupoom mount option and use its setting to set the
initial value of every memory.oom_policy?  That way the mount option
remains somewhat useful and we're back-compatible?