Re: [RFC v2] mm: Multi-Gen LRU: fix use mm/page_idle/bitmap

From: Yu Zhao
Date: Thu Dec 21 2023 - 23:36:12 EST


On Thu, Dec 21, 2023 at 7:45 PM Henry Huang <henry.hj@xxxxxxxxxxxx> wrote:
>
> Thanks for replyting.
>
> On Fri, Dec 22, 2023 at 07:16 AM Yuanchu Xie wrote:
> > How does the shared memory get charged to the cgroups?
> > Does it all go to cgroup A or B exclusively, or do some pages get
> > charged to each one?
>
> Some pages get charged to cgroup A, and the other get charged to cgroup B.

Just a side note:
We can potentially "fix" this, but it doesn't mean this is a good
practice. In fact, I think this is an anti-pattern to memcgs:
resources should be preferably isolated between memcgs, or if a
resource has to be shared between memcgs, it should be charged in a
predetermined way, not randomly to one of the memcgs sharing it.