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

From: Fabian Deutsch
Date: Thu Jun 15 2023 - 08:17:01 EST


On Thu, Jun 15, 2023 at 12:00 PM 贺中坤 <hezhongkun.hzk@xxxxxxxxxxxxx> wrote:
>
> > While looking at this in the past weeks, I believe that there are two distinct problems:
> > 1. Direct zram usage by process within a cg ie. a process writing to a zram device
> > 2. Indirect zram usage by a process within a cg via swap (described above)
> >
> > Both of them probably require different solutions.
> > In order to fix #1, accounting a zram device should be accounted towards a cgroup. IMHO this is something that should be fixed.
> >
> > Yu Zhao and Yosry are probably much more familiar with the solution to #2.
> > WRT per-cgrou-swapfile, to me this is addressing #2, but I agree with Yu Zhao, that there are probably better solutions to this.
> >
> > Lastly, this patchset, while it will possibly not address the swap issue (#2) completely, is it satisfying the needs of #1?
> >
> > - fabian
>
> Thanks for your reply, fabian. According to the previous design and
> test results, this patchset can meet the need of direct and
> indirect usage scenarios,charge the compressed memory to memory cgroup.

As said, I can not speak about the indirect swap case, but if it is
addressing the direct case, and putting the memory accounting on the
cgroup - then this would address one of the use-cases I have in mind.
Thanks!

- fabian