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 67566E91297 for ; Thu, 5 Feb 2026 09:04:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CBAA76B00BB; Thu, 5 Feb 2026 04:04:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CA63D6B00BD; Thu, 5 Feb 2026 04:04:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BA5636B00BE; Thu, 5 Feb 2026 04:04:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id A6F226B00BB for ; Thu, 5 Feb 2026 04:04:19 -0500 (EST) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 7A2EA13AF6B for ; Thu, 5 Feb 2026 09:04:19 +0000 (UTC) X-FDA: 84409816638.19.C6C87C2 Received: from out-183.mta1.migadu.com (out-183.mta1.migadu.com [95.215.58.183]) by imf16.hostedemail.com (Postfix) with ESMTP id 97FDE180008 for ; Thu, 5 Feb 2026 09:04:17 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=bMMa+8pR; spf=pass (imf16.hostedemail.com: domain of qi.zheng@linux.dev designates 95.215.58.183 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=1770282257; 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=Z51xqOUPrAhoh0O0GpdBH64DgayE69nJ4AY48cemOmg=; b=WiAr3uiqjD6cDzrhMGy6HBJLsKQyk3jqsze8kL5jd8ZMIJHpNs3OLTKPw+dpBRZTUP7oFE 0+N8OXWWxssXzmqTfWEuSUAK7AEdGDtdSRwpZxo2ZpsGDID4lX8W+afUW3r7cP3ypDAy1E DWZbhrLeNnvZzjI/+3xGZh9vax7Xuec= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=bMMa+8pR; spf=pass (imf16.hostedemail.com: domain of qi.zheng@linux.dev designates 95.215.58.183 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=1770282257; a=rsa-sha256; cv=none; b=1q82jtoOF41TJPg4+qefnp6U7GkPiPaa88YgvWoF2mEVgBgzZT5wceXKUz6DLh6N27TEK3 FAXzuOC/IFGF3IxQcT39QoU/YgzRyLya/gxH9MC+Bi2HQpftSrnic0ZWdNSgC74TyhsFCk oonKssQNDNLfskuL6p9ttJ3G5SidjRo= 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=1770282255; 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=Z51xqOUPrAhoh0O0GpdBH64DgayE69nJ4AY48cemOmg=; b=bMMa+8pRpvMevU5o7P6NsU1IxXKTc+bvGFohw4xmiWOB37yVdObh8wFaj4uWDIL8ZP0Ajf l25CZigM/807YogavESysrH/Fa5HpUiF38wM17snFCM7yXjs1qL4CKd9xHKhMhXOz1dkqN aorEwUkDMctoafCw7zpiPl1aPvRpcS8= 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 22/31] mm: workingset: prevent lruvec release in workingset_activation() Date: Thu, 5 Feb 2026 17:01:41 +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: 97FDE180008 X-Rspamd-Server: rspam07 X-Stat-Signature: 4z8af3cj7u4a8zbh9ai88nh19b6f5aek X-HE-Tag: 1770282257-778634 X-HE-Meta: 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 6bSWPG8J kACUnoFAQ5s8siC56ZMcLp7+COjFZBWkggsd0z5AgyhRaO2uhYFfEoyF0isjrYI1rlc5L2ASUqfYVvF6hHSc96f0I1bKPfB9CCriew5SbueYWOdzsGrbVyQRewCl3GK3FSMejf8yVlUMduXehyWCgC/VOLJNBd+TObq8JT+PjWrzDFemRYS7eqx48VG4xr9DrD4XgHmoQO8bBeExKx2JNbWw3fnR1xihmIJ2jDQjVwUSWG8Bqw+aXWMNiLvwBGINOCzXmgqITpqBy0vkOs4hhpwz44yB8IMQou+C+5BbHLfXM7BKMUQUMZ0Lw6g== 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_activation(). 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: Johannes Weiner Acked-by: Shakeel Butt --- mm/workingset.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/workingset.c b/mm/workingset.c index 5fbf316fb0e71..2be53098f6282 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -596,8 +596,11 @@ void workingset_activation(struct folio *folio) * Filter non-memcg pages here, e.g. unmap can call * mark_page_accessed() on VDSO pages. */ - if (mem_cgroup_disabled() || folio_memcg_charged(folio)) + if (mem_cgroup_disabled() || folio_memcg_charged(folio)) { + rcu_read_lock(); workingset_age_nonresident(folio_lruvec(folio), folio_nr_pages(folio)); + rcu_read_unlock(); + } } /* -- 2.20.1