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

贺中坤
2023-06-15T09:42:07Z

On Thu, Jun 15, 2023 at 1:00 PM Yu Zhao <yuzhao@google.com> wrote:
>
> 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/

Thanks for your reply. Yes, different memcgs may share the same zspages.