Re: [v8 0/4] cgroup-aware OOM killer

David Rientjes
2017-09-21T08:27:29Z

On Wed, 20 Sep 2017, Roman Gushchin wrote:

> > It's actually much more complex because in our environment we'd need an
> > "activity manager" with CAP_SYS_RESOURCE to control oom priorities of user
> > subcontainers when today it need only be concerned with top-level memory
> > cgroups. Users can create their own hierarchies with their own oom
> > priorities at will, it doesn't alter the selection heuristic for another
> > other user running on the same system and gives them full control over the
> > selection in their own subtree. We shouldn't need to have a system-wide
> > daemon with CAP_SYS_RESOURCE be required to manage subcontainers when
> > nothing else requires it. I believe it's also much easier to document:
> > oom_priority is considered for all sibling cgroups at each level of the
> > hierarchy and the cgroup with the lowest priority value gets iterated.
>
> I do agree actually. System-wide OOM priorities make no sense.
>
> Always compare sibling cgroups, either by priority or size, seems to be
> simple, clear and powerful enough for all reasonable use cases. Am I right,
> that it's exactly what you've used internally? This is a perfect confirmation,
> I believe.
>

We've used it for at least four years, I added my Tested-by to your patch,
we would convert to your implementation if it is merged upstream, and I
would enthusiastically support your patch if you would integrate it back
into your series.