From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=115.124.30.133 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793870576; b=acSMV5rgJK+5iA1CTH1DQgwHqxniKGyhU8Olxw8HITJIzbYrvIsaFfCmipyDNGqAwRf4 JRvkKCkyBK3+b7xNH6p1LB7dnR6mqrk4XIGDa0frTwqN4ktu3PGBR+vrdqzfZDNXrz6it qltDoF50k7ATbncbxYHaTdMLw4gzSe7LK8qtnJWTPwWxMo+ow4KJkCyHY2/HDtUhvwifw mVVx7er6jr8s/ieMJYcKjH02tuy2sxsjx0Ln+m667FOXVXmY63GqX/YXuFOrS87lw2lLy lpRCq8D/0vcl9yHUEcuZp+oTfqAR2ZavQP01EHKtSj6CuyKbftznZIErlw/uKa+S5Ag== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793870576; h=DMARC-Filter:DKIM-Signature:X-Alimail-AntiSpam:Received:From:To:Cc: Subject:Date:Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Type:Content-Transfer-Encoding; bh=zpf5QsizXx9EkATcGnWqX+gyIM8QWqLtiyYMZfErVsY=; b=0Uoe3C9aPwCGKg7bkFCQpEt/UAVxG/Ol3EdYkL/FzDUrL1EXL8ac7eJw4Q4Us+n+syCM xzKX0VYu1acQiZHXi9+axrLkV3Hs2WRDtu2bXDKP0yRdjXuWPm0QBPGHOiMhdsvvZmV/V fix17G8ArC6ZSNv2eNN9MrZR4Ic9OjRgjdFkrJjCb1mGvVyMkntNU5VwyrM1smK23iv+8 l0XhxBQm+hwRiBRgsWfmk3rnTnLcMimN+l3BiVxNaavtkaBFTvKB95trJkf1qxWSAB1M0 h+nAHQj+lxTlyiHv+G/nZUJEzaZYvO9JRythBcALWsqd6LriyqImxdAmULvCcdhD6bQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass header.d=linux.alibaba.com header.i=@linux.alibaba.com header.a=rsa-sha256 header.s=default header.b=uplXJedS; arc=none smtp.remote-ip=115.124.30.133 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F26F6606D834; Thu, 5 Nov 2026 09:22:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org F26F6606D834 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.a=rsa-sha256 header.s=default header.b=uplXJedS DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1793870566; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; bh=zpf5QsizXx9EkATcGnWqX+gyIM8QWqLtiyYMZfErVsY=; b=uplXJedSYoCFllIT1ZzqcL+VPKC/gGYaXTwr4K3cBNdkN9VCvvLPRnFIF+B5Zm1kc8FqncaANkSb9KgJwm4bWjYrrggB8if3X/ITOyKRdXCTX0MHddgDOzU0N4YYs6PVvz8eGzBxONZNREJQFT0jg8DkuNGh0QanWmNC7HBIUyk= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R351e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037026112;MF=qinyuntan@linux.alibaba.com;NM=1;PH=DS;RN=23;SR=0;TI=SMTPD_---0XE8K-1w_1793870562; Received: from banye.tbsite.net(mailfrom:qinyuntan@linux.alibaba.com fp:SMTPD_---0XE8K-1w_1793870562 cluster:ay36) by smtp.aliyun-inc.com; Thu, 05 Nov 2026 17:22:43 +0800 From: Qinyun Tan To: akpm@linux-foundation.org Cc: hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, mkoutny@suse.com, david@kernel.org, ziy@nvidia.com, baolin.wang@linux.alibaba.com, usama.arif@linux.dev, david@fromorbit.com, qi.zheng@linux.dev, yosry@kernel.org, nphamcs@gmail.com, chengming.zhou@linux.dev, xlpang@linux.alibaba.com, ryncsn@gmail.com, gourry@gourry.net, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Qinyun Tan Subject: [PATCH v4 RESEND 5/5] mm: zswap: mark the zswap shrinker SHRINKER_NONSLAB Date: Thu, 5 Nov 2026 17:22:33 +0800 Message-ID: <20261105092233.3558950-6-qinyuntan@linux.alibaba.com> X-Mailer: git-send-email 2.43.7 In-Reply-To: <20261105092233.3558950-1-qinyuntan@linux.alibaba.com> References: <20261105092233.3558950-1-qinyuntan@linux.alibaba.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With kmem accounting disabled (cgroup.memory=nokmem), memcg reclaim never invokes the zswap shrinker: a cgroup under memory pressure does not write back its own zswapped pages to make room; they are only written back by global reclaim or once the global pool limit kicks in. The zswap shrinker is registered memcg-aware but without SHRINKER_NONSLAB, so under nokmem it is treated as a slab shrinker: before commit 03375203e1da ("mm: do not allocate shrinker info with cgroup.memory=nokmem") it was skipped by the !memcg_kmem_online() check in shrink_slab_memcg(); since that commit it is demoted to non-memcg-aware at registration. But the zswap shrinker is not a slab shrinker: it tracks zswap entries and resolves the owning memcg from the folio's objcg, independent of kmem accounting. This was noticed by Michal during review of the patch "mm/list_lru: don't copy stale shrinker id from non-memcg-aware shrinkers". Mark it SHRINKER_NONSLAB so it keeps its memcg awareness and runs under memcg reclaim with nokmem. Link: https://lore.kernel.org/lkml/697713c4-0857-485b-aba7-c74f37a3c8b4@linux.alibaba.com/ Fixes: b5ba474f3f51 ("zswap: shrink zswap pool based on memory pressure") Suggested-by: Michal Koutný Signed-off-by: Qinyun Tan Acked-by: Usama Arif Acked-by: Nhat Pham Acked-by: Yosry Ahmed Reviewed-by: Johannes Weiner --- mm/zswap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index 572075bb1c1c..382ed1fb2847 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1348,8 +1348,8 @@ static struct shrinker *zswap_alloc_shrinker(void) { struct shrinker *shrinker; - shrinker = - shrinker_alloc(SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE, "mm-zswap"); + shrinker = shrinker_alloc(SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE | + SHRINKER_NONSLAB, "mm-zswap"); if (!shrinker) return NULL; -- 2.43.7