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

From: Michal Hocko
Date: Thu Jun 15 2023 - 10:20:58 EST


On Thu 15-06-23 22:13:09, 贺中坤 wrote:
> > This is not really answering my question though. memcg under hard limit
> > is not really my concern. This is a simpler case. I am not saying it
> > doesn't need to get addresses but it is the memcg hard limited case that
> > is much more interested. Because your charges are going to fail very
> > likely and that would mean that swapout would fail AFAIU. If my
> > understanding is wrong then it would really help to describe that case
> > much more in the changelog.
> >
>
> OK, Got it. In many cases I have tested, it will not fail because we did
> not charge the page directly,but the objects(like slab,compressed page),
> for the zspage may be shared by any memcg.

That sounds like a broken design to me.
--
Michal Hocko
SUSE Labs