Re: [PATCH v2 0/3] mm: memcontrol: recursive memory protection

From: Tejun Heo
Date: Thu Dec 19 2019 - 15:22:25 EST


On Thu, Dec 19, 2019 at 03:07:15PM -0500, Johannes Weiner wrote:
> Changes since v1:
> - improved Changelogs based on the discussion with Roman. Thanks!
> - fix div0 when recursive & fixed protection is combined
> - fix an unused compiler warning
>
> The current memory.low (and memory.min) semantics require protection
> to be assigned to a cgroup in an untinterrupted chain from the
> top-level cgroup all the way to the leaf.
>
> In practice, we want to protect entire cgroup subtrees from each other
> (system management software vs. workload), but we would like the VM to
> balance memory optimally *within* each subtree, without having to make
> explicit weight allocations among individual components. The current
> semantics make that impossible.

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

The original behavior turned out to be a significant source of
mistakes and use cases which would require older behavior just weren't
there.

Thanks.

--
tejun