Re: [PATCH 2/2] mm/mglru: stop rotating offlined memcgs to the old generation

[Baolin Wang <baolin.wang@linux.alibaba.com>]

On 10/28/26 9:06 AM, T.J. Mercier wrote:
> lru_gen_offline_memcg() moves an offlining memcg to the head of the old
> generation of the memcg LRU (MEMCG_LRU_OLD), so that global reclaim
> visits it first and evicts the folios it left behind.
> 
> Since commit f1cf8d2f36dc ("mm: memcontrol: eliminate the problem of
> dying memory cgroup for LRU folios"), those folios are reparented to the
> parent before lru_gen_offline_memcg() runs, and nothing can be added
> back to the offlined memcg's lruvec afterwards. Putting an empty
> offlined memcg at the head of the old generation no longer serves any
> purpose and only delays reclaim from the memcgs that still have memory
> due to additional shrink_many() iteration.
> 
> Remove lru_gen_offline_memcg(), so that an offlined memcg is rotated
> like any other memcg below the reclaimable size threshold until
> lru_gen_release_memcg() takes it off the memcg LRU. MEMCG_LRU_OLD has no
> other user, so remove the op and update the memcg LRU comment as well.
> 
> Signed-off-by: T.J. Mercier <tjmercier@google.com>
> ---

Thanks for the cleanups. LGTM.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>