Re: [RFC PATCH 1/3] zram: charge the compressed RAM to the page's memcgroup

Yu Zhao
2023-06-15T04:59:55Z

On Wed, Jun 14, 2023 at 9:48 PM Zhongkun He
<hezhongkun.hzk@bytedance.com> wrote:
>
> The compressed RAM is currently charged to kernel, not to
> any memory cgroup, which is not satisfy our usage scenario.
> if the memory of a task is limited by memcgroup, it will
> swap out the memory to zram swap device when the memory
> is insufficient. In that case, the memory limit will have
> no effect.
>
> So, it should makes sense to charge the compressed RAM to
> the page's memory cgroup.

We used to do this a long time ago, but we had per-memcg swapfiles [1[
to prevent compressed pages from different memcgs from sharing the
same zspage.

Does this patchset alone suffer from the same problem, i.e., memcgs
sharing zspages?

[1] https://lwn.net/Articles/592923/