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 1399AF30950 for ; Thu, 5 Mar 2026 11:57:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7FF896B00B7; Thu, 5 Mar 2026 06:57:30 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7D4056B00B9; Thu, 5 Mar 2026 06:57:30 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6ED4A6B00BA; Thu, 5 Mar 2026 06:57:30 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 5DA816B00B7 for ; Thu, 5 Mar 2026 06:57:30 -0500 (EST) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 1CE8558F8D for ; Thu, 5 Mar 2026 11:57:30 +0000 (UTC) X-FDA: 84511859460.06.996E088 Received: from out-178.mta0.migadu.com (out-178.mta0.migadu.com [91.218.175.178]) by imf06.hostedemail.com (Postfix) with ESMTP id 60D4018000F for ; Thu, 5 Mar 2026 11:57:28 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=O0ym4ixk; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf06.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1772711848; 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=ai/SdLNl7tLi9uYAWt04inUE82NVSwYAydx9AFMCLgs=; b=jUl6c3gR7LrmT2wzVyWPYm6FVt5s61oFBGcEXX2VwoWzOCtQcy7me1i5cG8AX36vuq/hzw ulfT2UMUF6BDKQ4SrJdbHCX/of98owbaiCwD/MIojOQ7NBEuf+G1LJk4FgEAfKkXR06hkV 4o4riCI4GXof5cvDs4+c/+IKWSGLWv4= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1772711848; a=rsa-sha256; cv=none; b=0W3cQQqD52TkKGPtpleF8c0usYU3rav/GyuZ02zo9byjafz12dKLX2eDYnqRdYYwvZ6htX ZjLKvHPZWkQQSTJs8JwID9dLCTVCYnSzuWxnvVcuuhec+vp5lcXJPPcrSnUp7opm3npvtD WjF3KlYF2nLDSNc0eTN1gA2e7Rxaeaw= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=O0ym4ixk; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf06.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev 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=1772711846; 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=ai/SdLNl7tLi9uYAWt04inUE82NVSwYAydx9AFMCLgs=; b=O0ym4ixk8FzaJ7HFtYmOOYBLKfjfYWDjCZjhkK2LYTeSQPb8f0NOUV2UvbOXWY0yjhQU+4 BptwqbI4fRWd2u+PtjvzfSzHtuyIz0GL5dgQyo0RGLo4BuSfGeEtMHogBq4uNW1m2F5FG+ jVuMqQaOq0J8WoGdp/eKdWwBrWbjSLE= 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, usamaarif642@gmail.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Muchun Song , Qi Zheng Subject: [PATCH v6 19/33] mm: workingset: prevent lruvec release in workingset_refault() Date: Thu, 5 Mar 2026 19:52:37 +0800 Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 60D4018000F X-Stat-Signature: osmx7ywkk5byzmu7z17q1n75oois386d X-Rspam-User: X-HE-Tag: 1772711848-230053 X-HE-Meta: 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 38ua15dq MGTYXpemAKuNTF3nBzfY1/BuT/+5lAusg47XeE2cCZcAdc03ITdgPAW3t8p2kUoR2nv9yFm6itCHKaTMn6hymgSbztAlmscPJqnSXZc27arpQFR+WsOaa+TvcQPhRwX2VnAqsY2OFql/IzH3LvmcJfPSTwtgXCDy5Gj3bSEhc91KG0DgvAzUDiNScLwKI7bqqL21sOhemjKadSE603lMGnoYO8L+NiDA1HUY6yZTn3Zl8VTcmF9Y7pfw3zAOoWJflSmt9 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 workingset_refault(). This serves as a preparatory measure for the reparenting of the LRU pages. Signed-off-by: Muchun Song Signed-off-by: Qi Zheng Reviewed-by: Harry Yoo Acked-by: Shakeel Butt --- mm/workingset.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/mm/workingset.c b/mm/workingset.c index 6971aa163e466..2de2a355f0f86 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -546,6 +546,7 @@ bool workingset_test_recent(void *shadow, bool file, bool *workingset, void workingset_refault(struct folio *folio, void *shadow) { bool file = folio_is_file_lru(folio); + struct mem_cgroup *memcg; struct lruvec *lruvec; bool workingset; long nr; @@ -567,11 +568,12 @@ void workingset_refault(struct folio *folio, void *shadow) * locked to guarantee folio_memcg() stability throughout. */ nr = folio_nr_pages(folio); - lruvec = folio_lruvec(folio); + memcg = get_mem_cgroup_from_folio(folio); + lruvec = mem_cgroup_lruvec(memcg, folio_pgdat(folio)); mod_lruvec_state(lruvec, WORKINGSET_REFAULT_BASE + file, nr); if (!workingset_test_recent(shadow, file, &workingset, true)) - return; + goto out; folio_set_active(folio); workingset_age_nonresident(lruvec, nr); @@ -587,6 +589,8 @@ void workingset_refault(struct folio *folio, void *shadow) lru_note_cost_refault(folio); mod_lruvec_state(lruvec, WORKINGSET_RESTORE_BASE + file, nr); } +out: + mem_cgroup_put(memcg); } /** -- 2.20.1