From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-166.mta1.migadu.com [95.215.58.166]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EFB3526296 for ; Sat, 15 Aug 2026 00:48:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.166 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786754933; cv=none; b=A7E4JegtpqSByodHdzDvIcS4inUH18WMcOK6JO9lnh9sThsF/7ea8yRSq+4CefWgTut6T16yNtDPl2XTRgUCWwQtUGZFpQAtaxt05t0qUHQT4azVdKYlyBwqbzNaAIcg0V/nYFz/qPMJQW93qgjqBPgoadcmoAP7ThskVgP00Nw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786754933; c=relaxed/simple; bh=D2tHr41vvRZOGh8CfotiS63LZpn9WEESIso0qi3hUnc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ewIl1lKSI8olaCXvZ4CM8cQbZ4ZFsYrLastHr/OpM5g2KOtRi92aWLx7shxvX4FOzwmBEvQk2ShIZZaihsTFRe6kIm/Ee/rG4/kMf0p5W+DBERlZEdnQfefZizO/AhYavox//yYJqIuJ+k+sJUAIhzHMDs/j6216tYi3dyo4s4c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=M/iz1KRZ; arc=none smtp.client-ip=95.215.58.166 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="M/iz1KRZ" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=D2tHr41vvRZOGh8CfotiS63LZpn9WEESIso0qi3hUnc=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1786754928; v=1; x=1787359728; b=M/iz1KRZ0lTqKQZPuHWE8x3SeGdOLunKWprCkF0Dgj/TsGb/fkncKsgqGHuMZGCmzFBiyPnL cT21e0jdaxqQPpW59MxViYonn4zSWPT7iufa4AqAiBX7/jlJZR9VmmN7AJgK46C5NETt0zUn2Ny 9VpinGuAWToyq70d7paTn19U= X-Envelope-To: linux-kernel@vger.kernel.org Received: from localhost (2a03:2880:10ff:12::) by smtp.migadu.com with ESMTPS id f2405bb7f12b9bff; Sat, 15 Aug 2026 00:48:48 +0000 X-Migadu-Flow: FLOW_OUT Date: Fri, 14 Aug 2026 17:48:47 -0700 From: Shakeel Butt To: "Lorenzo Stoakes (ARM)" Cc: Andrew Morton , Michal Hocko , Johannes Weiner , Roman Gushchin , Muchun Song , David Hildenbrand , Kairui Song , Qi Zheng , Barry Song , Axel Rasmussen , Meta kernel team , 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 Message-ID: References: <20260811203203.3456029-1-shakeel.butt@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Aug 13, 2026 at 10:27:09AM +0100, Lorenzo Stoakes (ARM) 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] > > > > Shakeel Butt (9): > > memcg: make the v1 soft limit knob inert > > memcg: remove v1 soft limit reclaim > > memcg: remove mem_cgroup_shrink_node() > > memcg: remove the soft limit reclaim tracepoints > > memcg: remove the soft limit rbtree > > memcg: remove lru_gen_soft_reclaim() > > memcg: remove the per-node soft limit tree fields > > memcg: remove mem_cgroup->soft_limit > > memcg: simplify v1 event ratelimiting > > > > .../admin-guide/cgroup-v1/memory.rst | 49 +- > > include/linux/memcontrol.h | 27 -- > > include/linux/mmzone.h | 30 +- > > include/trace/events/vmscan.h | 14 - > > mm/internal.h | 4 - > > mm/memcontrol-v1.c | 435 ++---------------- > > mm/memcontrol-v1.h | 12 +- > > mm/memcontrol.c | 7 +- > > mm/vmscan.c | 96 +--- > > 9 files changed, 66 insertions(+), 608 deletions(-) > > This is a gorgeous diffstat :) > > Obviously not my area but looking over it, all LGTM so feel free to add: > > Acked-by: Lorenzo Stoakes (ARM) > > To the whole series! Thanks for the review.