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 B780DE91290 for ; Thu, 5 Feb 2026 09:03:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 242E66B00B5; Thu, 5 Feb 2026 04:03:54 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1D95C6B00B7; Thu, 5 Feb 2026 04:03:54 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0D90F6B00B8; Thu, 5 Feb 2026 04:03:54 -0500 (EST) 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 F1A7E6B00B5 for ; Thu, 5 Feb 2026 04:03:53 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id B81B214043B for ; Thu, 5 Feb 2026 09:03:53 +0000 (UTC) X-FDA: 84409815546.14.71B41C1 Received: from out-186.mta1.migadu.com (out-186.mta1.migadu.com [95.215.58.186]) by imf06.hostedemail.com (Postfix) with ESMTP id E38D018000D for ; Thu, 5 Feb 2026 09:03:51 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=KVfh9JeK; spf=pass (imf06.hostedemail.com: domain of qi.zheng@linux.dev designates 95.215.58.186 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=1770282232; 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=JRi+VmXiW8HlsHjnS6VBfEapdpTlECLdprrexkoF+xY=; b=4NYX6Izhtk21is2XyGQodfu/TtrLJkZ848Lzgq5rCByLGYbeeY9TTJKJLtV2teQRKaNsWJ nbpfIrfHUBydQ7dEGrnqTPMWVl7GBkQ3jVT53wy5MdJt4j/iScr4ae3JiooTTNfpuW+Jmf GNkkhFAiULnDmQSdUPgTtCrHLrB23Dg= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=KVfh9JeK; spf=pass (imf06.hostedemail.com: domain of qi.zheng@linux.dev designates 95.215.58.186 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=1770282232; a=rsa-sha256; cv=none; b=U8RSn0qRp2ZVbVvRP9R4h5o6P3TplpfIs4uEkZ/pMBAHQ8elzdzm8aEmfDObl/3FAYVRAG rLyFqt2aFy7a/zXxe1HKCM0hq5+CHNvcOGm9qdD4HVxio94YqIWZQc4t+QtyPQwtzbjxTe fxlFZicdyQS8qgCwaAY7TaG+tfvnnDY= 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=1770282230; 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=JRi+VmXiW8HlsHjnS6VBfEapdpTlECLdprrexkoF+xY=; b=KVfh9JeKpVTMnjxhHqZOl5kWuMUmCKOj23QCvuPn7hKW652FwNQuQF6mDdpkeV27rgECqr ynr8o4Zuwu9IPgsC5o/cHoZT05/tLITASawjRLQR1CHWrNimtaU9i0/mY5LECvobbPE0o7 bP7KqOjQmgjiuffVgrpXepU4iPO8vxs= 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 , Qi Zheng Subject: [PATCH v4 19/31] mm: workingset: prevent lruvec release in workingset_refault() Date: Thu, 5 Feb 2026 17:01:38 +0800 Message-ID: <20da5d43b253f4810c939aad5ebac0141438271a.1770279888.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-Rspamd-Queue-Id: E38D018000D X-Rspamd-Server: rspam07 X-Stat-Signature: pckupg3qjgsapxyex4o6rc76cn5oi6rc X-HE-Tag: 1770282231-675695 X-HE-Meta: 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 QlRC5ESY KkB0vTMzk3xAPHGPjTGxMRjmRhfQtPf7+Nx4koS73BtDSCKHALWogGBe5h+DonnpLgrqU9OG3lTRdMZeiw1I+xg4h4sWyCXS2lndlMblCl8PeLJkkfizOM6sXfwBMehVeGelzXTWJoFkmdxwg/hoPGjXM7gQnQAKHs9gvERgvjHJ6jgmxLJ9nFpdSNNggVA8eJuaJEENJKOAJOWfMeD731PbSpZb8F3v/JdMxyX7gsScaOg2gsiwYH0VHC0cyi4m/iQ2i 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 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 79b40f058cd48..5fbf316fb0e71 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -539,6 +539,7 @@ 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; @@ -560,11 +561,12 @@ 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); @@ -580,6 +582,8 @@ 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