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 F39E1D29FF0 for ; Wed, 14 Jan 2026 11:35:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 679536B00B3; Wed, 14 Jan 2026 06:35:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 646FD6B00B5; Wed, 14 Jan 2026 06:35:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 57A126B00B6; Wed, 14 Jan 2026 06:35:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 465FC6B00B3 for ; Wed, 14 Jan 2026 06:35:12 -0500 (EST) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 086308BB3A for ; Wed, 14 Jan 2026 11:35:12 +0000 (UTC) X-FDA: 84330363264.12.A2C89CF Received: from out-178.mta0.migadu.com (out-178.mta0.migadu.com [91.218.175.178]) by imf22.hostedemail.com (Postfix) with ESMTP id 41BD7C0004 for ; Wed, 14 Jan 2026 11:35:10 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b="Y/yBXxCT"; spf=pass (imf22.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1768390510; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=x6JB5m1zaMYn2/Ai4L76w6jnabp6L6YH+5GHcHxDnBk=; b=UEOQbKnTGrbCgp7CNL5pwDPQU6GqARo0dasWkiA8VZEZqi0TGcYQFZvdTlVnDlUK8NRX72 e8vBdDcs7XGDy+MStdIJoNUhGboOodYcgvCYiZJoGp9bbsgTx0+4Ozm5+IuKChT8t0jBPq FoBaC9Eq9/S8xPbTbmbS/yTVERTYzQQ= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b="Y/yBXxCT"; spf=pass (imf22.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1768390510; a=rsa-sha256; cv=none; b=JaPor+0z1ze+Zp5tyqOV7FGBuak8553fv3jpgbOgCijaHmtzuDgjgVwiN0nVa7QT5bbIC0 mz1GEiLlVKpZ19HQ8RlXP/nb8Qurc69iLoTsEN4WyIEtlVciZPJmRAxvrGIopx6oaxslNg WQZUj/UGHiictGkHhG3A9iSvk9zsbK8= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1768390508; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=x6JB5m1zaMYn2/Ai4L76w6jnabp6L6YH+5GHcHxDnBk=; b=Y/yBXxCTUVdP2n9SBbZyG8Lc/xRQAiUdP5P558HckIsV6pJK0v7HbDoVAJHfNPSTCECRr8 80RdFRjJXxeM9qTN3JRSTaonKimhQZvOAYTFJCfj17L1M36EYvF0MX+zfe4HOct0bnHKuT a4qrZ4wOSs5GKn/GOQdwJ0vKQhDR/mA= From: Qi Zheng To: hannes@cmpxchg.org, hughd@google.com, mhocko@suse.com, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, david@kernel.org, lorenzo.stoakes@oracle.com, ziy@nvidia.com, harry.yoo@oracle.com, yosry.ahmed@linux.dev, imran.f.khan@oracle.com, kamalesh.babulal@oracle.com, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, chenridong@huaweicloud.com, mkoutny@suse.com, akpm@linux-foundation.org, hamzamahfooz@linux.microsoft.com, apais@linux.microsoft.com, lance.yang@linux.dev Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Muchun Song , Nhat Pham , Chengming Zhou , Qi Zheng Subject: [PATCH v3 20/30] mm: zswap: prevent lruvec release in zswap_folio_swapin() Date: Wed, 14 Jan 2026 19:32:47 +0800 Message-ID: <971b3834f87d6dc87a0634bcca8c45f26907e262.1768389889.git.zhengqi.arch@bytedance.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Stat-Signature: 1u4x55xbd1n4cyktipm5mri1g51iqrkd X-Rspamd-Queue-Id: 41BD7C0004 X-Rspamd-Server: rspam04 X-HE-Tag: 1768390510-691299 X-HE-Meta: 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 4ZBafd0R cHMk/neGltWZ8ZAX6GG3DCfdZ6iB+sHZgrWLLdNzoIU8z4eVeZ6zKNJ+7BsGwHX7p454YyqbDq88q8s2DlucsgzgaRQ6RUOkHkMRnxj7Le3xE2DN/M3MEAwWoyEUTFnraJkBreykbtkb78qmmNUphN3ULutWb838qmhuoazfSjgktWGxqG84Gqht4ilyuotJVKx4u0H3aIWv1+ICLh21rna8V7Lyn1bFS3nKAcZUArb960FZPnShsEBFhvjuyXMafrYFu3yjZye6vMunJTDGmw+qahytciVcQyXxrcr5G5y9bb0P6WhMqPItw+WPijty0rkLHbYOBy/k8FwqYwakXjMnF9w== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Muchun Song In the near future, a folio will no longer pin its corresponding memory cgroup. So an lruvec returned by folio_lruvec() could be released without the rcu read lock or a reference to its memory cgroup. In the current patch, the rcu read lock is employed to safeguard against the release of the lruvec in zswap_folio_swapin(). This serves as a preparatory measure for the reparenting of the LRU pages. Signed-off-by: Muchun Song Acked-by: Nhat Pham Reviewed-by: Chengming Zhou Signed-off-by: Qi Zheng Reviewed-by: Harry Yoo Acked-by: Johannes Weiner Acked-by: Shakeel Butt --- mm/zswap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/zswap.c b/mm/zswap.c index cd926e1c03c92..2f410507cbc8b 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -663,8 +663,10 @@ void zswap_folio_swapin(struct folio *folio) struct lruvec *lruvec; if (folio) { + rcu_read_lock(); lruvec = folio_lruvec(folio); atomic_long_inc(&lruvec->zswap_lruvec_state.nr_disk_swapins); + rcu_read_unlock(); } } -- 2.20.1