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Date: Fri, 28 Aug 2026 19:43:22 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Michal Hocko <mhocko@suse.com>, Johannes Weiner <hannes@cmpxchg.org>,
 Roman Gushchin <roman.gushchin@linux.dev>, Muchun Song
 <muchun.song@linux.dev>, David Hildenbrand <david@kernel.org>, Lorenzo
 Stoakes <ljs@kernel.org>, Kairui Song <kasong@tencent.com>, Qi Zheng
 <qi.zheng@linux.dev>, Barry Song <baohua@kernel.org>, Axel Rasmussen
 <axelrasmussen@google.com>, Meta kernel team <kernel-team@meta.com>,
 linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH for-7.4 0/9] memcg: remove the v1 soft limit
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In-Reply-To: <apJCb-8RK0azF8_h@linux.dev>
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On Fri, 28 Aug 2026 19:23:19 -0700 Shakeel Butt <shakeel.butt@linux.dev> wrote:

> On Tue, Aug 11, 2026 at 01:31:54PM -0700, Shakeel Butt wrote:
> > Syzbot reported [1] a set_mm_walk() warning from kswapd. Soft limit
> > reclaim is the only thing that runs shrink_lruvec() from kswapd with a
> > target memcg set, and thus the only way kswapd can reach
> > lru_gen_shrink_lruvec() and in turn set_mm_walk(). The offender,
> > mem_cgroup_shrink_node(), has long carried a "Only used by soft limit
> > reclaim. Do not reuse for anything else." comment and a priority hack,
> > and it simply never got taught about MGLRU.
> > 
> > Rather than teach it, let's delete it. The v1 soft limit was deprecated
> > in v6.12 by commit 569c4f62d84a ("memcg: initiate deprecation of v1
> > soft limit"). Nobody has reported depending on it in the ~21 months
> > since, and v2 has covered the same ground for a long time with
> > memory.low and memory.min.
> > 
> > Link: https://lore.kernel.org/all/6a7a6929.b50370da.49fe0.005e.GAE@google.com/ [1]
> 
> Andrew, should I resend this series (without the first patch) or will you pick
> it up?

I added the series, thanks.

The [1/9] has already been queued in mm-hotfixes as a backportable
hotfix.  So I added it as an 8-patch series.  Because of this the cover
letter of that series is now irrelevant, so could you please prepare a
brief replacement for me to paste in?

Sashiko suggests that there's more that can be removed:
	https://sashiko.dev/#/patchset/20260811203203.3456029-1-shakeel.butt@linux.dev

So maybe an 8-patch v2 series is appropriate, your call.