From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E5C7AC79F99 for ; Mon, 7 Sep 2026 11:01:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BAAD06B00AF; Mon, 7 Sep 2026 07:01:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B82C56B00B0; Mon, 7 Sep 2026 07:01:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A98C96B00B1; Mon, 7 Sep 2026 07:01:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 896F66B00AF for ; Mon, 7 Sep 2026 07:01:27 -0400 (EDT) Received: from smtpin08.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 1CD321C002C for ; Mon, 7 Sep 2026 11:01:27 +0000 (UTC) X-FDA: 85186675014.08.0BFDBAC Received: from out30-124.freemail.mail.aliyun.com (out30-124.freemail.mail.aliyun.com [115.124.30.124]) by imf17.hostedemail.com (Postfix) with ESMTP id F123B40002 for ; Mon, 7 Sep 2026 11:01:24 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=linux.alibaba.com header.s=default header.b=wJY5T8FT; spf=pass (imf17.hostedemail.com: domain of qinyuntan@linux.alibaba.com designates 115.124.30.124 as permitted sender) smtp.mailfrom=qinyuntan@linux.alibaba.com; dmarc=pass (policy=none) header.from=linux.alibaba.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1788778885; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/kTenwfhjwRZAsn2gE4kzIQoYtAxda9Qf9Jtbo1G+2k=; b=fYxikdzshHlQMPNw7simZgG2z1QioT5e/B5/ydNLzsIgyic3TYwSfgX2VXe+VgA3EX9zep sBP8PbY7Q2MVYLRZdyXhVnGEDtzEp7U9XWwnsGU+H38MPlvejRG1MPRSQE28VBe3l6YQ1h BO9m1x1EBYRGoKGQjK/3X1fHoQ0hOZs= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=linux.alibaba.com header.s=default header.b=wJY5T8FT; spf=pass (imf17.hostedemail.com: domain of qinyuntan@linux.alibaba.com designates 115.124.30.124 as permitted sender) smtp.mailfrom=qinyuntan@linux.alibaba.com; dmarc=pass (policy=none) header.from=linux.alibaba.com ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1788778885; b=KrDpSuC02u3nmz+jN9xsBQr/zd9Fj36/F29GZhcTaaWizAABq1T1XQnrHi3fXG0NOTDoWa lymxDwkdXjm69zgpkMao5UP4viJt89gycz6M5qpmABrp0wHtWRd0RIVB4YGN4mKKx5GUzE cfdRLUxjNHqCrJiltWFXUCexpIGMScQ= DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1788778882; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; bh=/kTenwfhjwRZAsn2gE4kzIQoYtAxda9Qf9Jtbo1G+2k=; b=wJY5T8FTg0WFaqoVnp4LoXV65gf9lviLlcMjIDiEoemAwcQRM2AZI1PpxiVZEGkTny3qp8O1wwCSpkXH1oM7b7cPmo25xGvGNLfCa9zDBkWYFcuB+ut72R8xqr4rgrk38kuQNzk2nIQ3Og0DrZ3xpI7HB+9HNdCQkErzNdDzQys= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R161e4;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=21;SR=0;TI=SMTPD_---0XATsw.a_1788778880; Received: from banye.tbsite.net(mailfrom:qinyuntan@linux.alibaba.com fp:SMTPD_---0XATsw.a_1788778880 cluster:ay36) by smtp.aliyun-inc.com; Mon, 07 Sep 2026 19:01:21 +0800 From: Qinyun Tan To: Andrew Morton Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , =?UTF-8?q?Michal=20Koutn=C3=BD?= , David Hildenbrand , Zi Yan , Baolin Wang , Usama Arif , Dave Chinner , Qi Zheng , Yosry Ahmed , Nhat Pham , Chengming Zhou , Xunlei Pang , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Qinyun Tan Subject: [PATCH v2 4/4] mm: zswap: mark the zswap shrinker SHRINKER_NONSLAB Date: Mon, 7 Sep 2026 19:01:11 +0800 Message-ID: <20260907110111.2286932-5-qinyuntan@linux.alibaba.com> X-Mailer: git-send-email 2.43.7 In-Reply-To: <20260907110111.2286932-1-qinyuntan@linux.alibaba.com> References: <20260907110111.2286932-1-qinyuntan@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Stat-Signature: a44j4gjd5rmhq8dkg78kbpoo7tdst85c X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: F123B40002 X-Rspam-User: X-HE-Tag: 1788778884-658410 X-HE-Meta: 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 uDEhI8OJ jkSg8A1GxdMI7LeMSNbSZnkfVJateG/xrQNWdPtRsQBh7qkBQR8s+G781JfwinGTXoKCjca8RcCDXSAwnpl9L3RKxLGy/5WducwAtb8u8WzqjICDR2fUUnXRZWimBVWTF2X40G9/efdRbDAACAPQivDrQQijnD1qzJCcTrfZKIqkvU07e0cgvIF+M4dp4tJPbs5KerMrmET/9a4dS16WK0Ag23ra1mOVK87JljrXxZGoN2l7DCPdNCmeh0aGhkgaBZzdfTnIuXU1omLPfFhxZDnR30X/A3aHLBwuDeyN/buMOmMWloAN43ecm7CNeQ1BRKxPYiNVpBIyKVak/QxqZf0gHytnVBztjhH37svFRG+UT8rJ7zbTNypaz1H5uMdGL6zD/mKpxR3/6QaN7Rx16EGyduTEJmtQP8HpW Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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" [1]. Mark it SHRINKER_NONSLAB so it keeps its memcg awareness and runs under memcg reclaim with nokmem. [1] 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 --- mm/zswap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index f3ae3c81e48ea..032136942c172 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1252,8 +1252,8 @@ 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