Re: [PATCH v2 00/28] Eliminate Dying Memory Cgroup

[Qi Zheng]

On 12/29/25 5:35 PM, Harry Yoo wrote:
> On Mon, Dec 29, 2025 at 03:48:26PM +0800, Qi Zheng wrote:
> > On 12/24/25 7:20 AM, Shakeel Butt wrote:
> > > On Tue, Dec 23, 2025 at 08:04:50PM +0000, Yosry Ahmed wrote:
> > > [...]
> > > > I think there might be a problem with non-hierarchical stats on cgroup
> > > > v1, I brought it up previously [*]. I am not sure if this was addressed
> > > > but I couldn't immediately find anything.
> > >
> > > Sigh, the curse of memcg-v1. Let's see what we can do to not break v1.
> >
> > The memcg-v1 was originally planned to be removed, could we skip
> > supporting v1?
>
> You mean not reparenting LRU pages if CONFIG_MEMCG_V1 is set?
>
> That may work, but IMHO given that there is no clear timeline for removal
> yet (some v1-specific features have been officially deprecated,
> but memcg v1 as a whole hasn't), implementing Shakeel's suggestion [1]
> may be a good option (it doesn't seem to add much complexity)
>
> But it can be argued that it's not good enough reason to
> delay the series; adding support for V1 later sounds sensible to me.

Yeah, I will continue to take a closer look at how to support memcg-v1.

> Anyway I'm fine either way and I'm not a memcg maintainer myself,
> so this is just my two cents.
>
> [1] https://lore.kernel.org/linux-mm/wvj4w7ifmrifnh5bvftdziudsj52fdnwlhbt2oifwmxmi4eore@ob3mrfahhnm5/