Re: [RFC PATCH 0/3] mm, memcg: isolate deprecated v1 state from struct mem_cgroup

[Roman Gushchin <roman.gushchin@linux.dev>]

Tao Cui <cui.tao@linux.dev> writes:

> Hi Roman,
>
> 在 2026/10/30 14:05, Roman Gushchin 写道:
>> I believe we want to delete this code sooner than later, why would we rewrite it before that?
>> 
>
> My assumption was that v1 would still be maintained for some time
> before its eventual removal, and the goal was to reduce the coupling
> between the remaining v1 code and the shared core structures during
> that period, rather than to rewrite the implementation for its own
> sake.

I understand. But personally I don't see big issues with the current
code caused by the v1 stuff. Maybe I miss something...

The proposed changes on the other hand create difficulties for those
who use v1 and maintain some local changes or simple backport upstream
fixes. Of course, it's not a reason to not change the upstream code if
it's justified, but in this case I'm hardly convinced.

> If the expectation is that the remaining v1 implementation will be
> removed in the near future, then I agree this work becomes much harder
> to justify.
>
> Am I being too optimistic about how long the remaining v1 code is
> expected to stay around?

Well, Idk, it was considered deprecated for quite some time already,
so maybe announcing that it will be deleted in a year is reasonable?

Shakeel, Johannes, Michal, wdyt?