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 0EF10E91297 for ; Thu, 5 Feb 2026 09:04:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6EDF66B00B7; Thu, 5 Feb 2026 04:04:03 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6D92E6B00B9; Thu, 5 Feb 2026 04:04:03 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5AE706B00BA; Thu, 5 Feb 2026 04:04:03 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 489F66B00B7 for ; Thu, 5 Feb 2026 04:04:03 -0500 (EST) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 13F40C1B1C for ; Thu, 5 Feb 2026 09:04:03 +0000 (UTC) X-FDA: 84409815966.27.7AC4A49 Received: from out-181.mta1.migadu.com (out-181.mta1.migadu.com [95.215.58.181]) by imf23.hostedemail.com (Postfix) with ESMTP id 63E37140006 for ; Thu, 5 Feb 2026 09:04:01 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=T9tFkJs7; spf=pass (imf23.hostedemail.com: domain of qi.zheng@linux.dev designates 95.215.58.181 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=1770282241; 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=TuhMoOfRbvDRr52ITJW32CIqePtfQkF24X/lt5AE2Eo=; b=kBUEWWSSsgi9to65QOqIgN8Au9Co4FLcYQejfQLtBBgdw4rWM7ohvoqt4Z497BOGu5gMzS /1BWkHWdOquB0A7WjGduo1If5IVIGKwBQR9q2bPoy/jonOXpQ8Yjb6Wmb/weQ2++pXK3RX rympQR3qTayP5DSaRd6ZUFTzYlIRO3I= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=T9tFkJs7; spf=pass (imf23.hostedemail.com: domain of qi.zheng@linux.dev designates 95.215.58.181 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=1770282241; a=rsa-sha256; cv=none; b=qoYDgGk7+iVjDcYw/LtKfPWj3IsEYT2QqrcC+5ymMgeL2Owf8eQ1UkNui+HdRstYYDRvDF g2ajDnE3lWkVXlVpH7ZocuS+rcnznYuUL/KDyRrRR9b7nP5sW/igr3wPcEUnok8iYZZLOO fzbGFpCikNFhMkav/KEzkk5ApjB7HmM= 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=1770282239; 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=TuhMoOfRbvDRr52ITJW32CIqePtfQkF24X/lt5AE2Eo=; b=T9tFkJs7ctZ0NCtrcpZ8FGPMeUOscchOZ/GeyGeplqd3G7G12nmIo0kc4sHfKcallmV8jU 08APyxlfApctPlNsY6t8VBeNCJC++rC0NB2qBGll/JPk9KIB7NqR8sNmTTawzQtZZHdZYp RwEvA/GSIClVZp7VXmNQleupJH2Y9bs= 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, bhe@redhat.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Muchun Song , Nhat Pham , Chengming Zhou , Qi Zheng Subject: [PATCH v4 20/31] mm: zswap: prevent lruvec release in zswap_folio_swapin() Date: Thu, 5 Feb 2026 17:01:39 +0800 Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Queue-Id: 63E37140006 X-Rspamd-Server: rspam07 X-Stat-Signature: 14wdgx35ajoc9sug8ifq8h5888ugrpqx X-HE-Tag: 1770282241-923492 X-HE-Meta: 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 HPTpgGwM RzVzWy6+dZAxqgC6HApHYfVHh0XagmR17Tfrki0YMYM6tIMeSX3WrHEwgAFU9NIa57OaTWdzrd6+He1BGHclPlYkFyZWD+zHb5B01VDT3giI+0OWoQH0PRmFfin7tUh8yBzRr6U0B9wvdBGR3uZ+/whLmDEtInZ6wK0bDSpKTMI60NUjwo9B98qXN/LH0LyxsDw1xQrXArdqM8ly4C5bjsz508XzBcc4+lBUcZaMX159oruyc/Fsqwv8VQ62thXrD1SrRFjqK2WEcat/toj8o0Cp+jcrbW3YOhWhDbO0g4a71Ro2R9ZM5mAeuM9h/0Dd9bJ0SRPVbXFkIoCVB2f67W+2bWw== 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 a9319ecd92b4b..aea3267c5a967 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -664,8 +664,10 @@ 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