Re: [PATCH v2 0/8] memcg: remove the v1 soft limit

From: Andrew Morton

Date: Wed Sep 02 2026 - 16:32:13 EST


On Wed, 2 Sep 2026 10:43:03 -0700 Shakeel Butt <shakeel.butt@xxxxxxxxx> wrote:

> The v1 soft limit was deprecated in v6.12 by commit 569c4f62d84a ("memcg:
> initiate deprecation of v1 soft limit") and nobody has reported depending
> on it in the ~21 months since. memory.low and memory.min in v2 have
> covered the same ground for far longer.
>
> The knob has since been made inert by "memcg: make the v1 soft limit knob
> inert", already queued in mm-hotfixes as a backportable fix for a syzbot
> report [1]. Nothing can enter the soft limit rbtree anymore, so this
> series just deletes the machinery that is now dead: the reclaim pass in
> kswapd and direct reclaim, mem_cgroup_shrink_node() and its tracepoints,
> the per-node rbtree, lru_gen_soft_reclaim() and the MEMCG_LRU_HEAD op, the
> per-node tree fields, mem_cgroup->soft_limit, and finally the v1 event
> ratelimiting which is now down to a single target.
>
> memory.soft_limit_in_bytes itself is untouched: writes stay ignored and
> reads keep returning the maximum value.

Thanks, I updated mm-unstable.

> Changes since v1 [2]:
> - Dropped "memcg: make the v1 soft limit knob inert" (1/9 in v1), which is
> already queued in mm-hotfixes, making this an 8-patch series.
> - Collected the acks and review tags. No code changes.

I've confirmed that v2 made no alterations to mm.git.