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 70E8CEFD204 for ; Wed, 25 Feb 2026 07:54:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D034E6B00B5; Wed, 25 Feb 2026 02:54:40 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CC44C6B00B7; Wed, 25 Feb 2026 02:54:40 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BE3E06B00B8; Wed, 25 Feb 2026 02:54:40 -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 A74856B00B5 for ; Wed, 25 Feb 2026 02:54:40 -0500 (EST) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 6F288160399 for ; Wed, 25 Feb 2026 07:54:40 +0000 (UTC) X-FDA: 84482217120.04.CC91BDA Received: from out-185.mta0.migadu.com (out-185.mta0.migadu.com [91.218.175.185]) by imf22.hostedemail.com (Postfix) with ESMTP id B8462C000D for ; Wed, 25 Feb 2026 07:54:38 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=FIZR0Qm6; spf=pass (imf22.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.185 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=1772006078; 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=mZ/bi8R/JQ+WZrr+GidcAj9qanmqyMImkHRJbrEQgs7S+Y23qIZej4T+dLc4Vu4LLnzZS0 cDXvGSh23zrJ13xia57ZVTQHx1YBlm3jaxVeX5XfxdHoMNgpZe/TeLBuNZOyqFP/32ED1h X2TsyOrtBPXrSjlyo47bbt2+LA+30u0= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=FIZR0Qm6; spf=pass (imf22.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.185 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=1772006078; a=rsa-sha256; cv=none; b=6ZvDs1geIHzDlWlfcorOtDV6xNu6t3ieBOXhkj3KKwS38TN/T7MTmfW1r7pUKyA54tPE6f IPodcAMltobGyqg1SQRAciityIIJjpzBOJ/vIcQghH+rkcO6RN7rAgT9Lmg/delCU/+rMV lMcrpOUfk/uekQaRXfjaqVHy0Z2jI7A= 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=1772006077; 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=FIZR0Qm6YsSN2bu+kckrpQ3wMkRnx5m8rMnPbZ0u/yPdaJZS/plcMwHKY0/yuQiRSTnI26 v1IUp1pu9lbGYmtwTTAUwyTBfLrEFeLngzNrzcj6ltsC2MNiAGC9erc18yrZDVmvepotcJ 1KNooDChqwnGs3TJ6DD3JQhD5ELe9lM= 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 v5 19/32] mm: workingset: prevent lruvec release in workingset_refault() Date: Wed, 25 Feb 2026 15:53:02 +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: B8462C000D X-Rspamd-Server: rspam02 X-Stat-Signature: fwxzrekdnu51ncpa77smw3m7ak7xadms X-HE-Tag: 1772006078-122183 X-HE-Meta: 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 VPvwCDuX jEULJjyJXCopzku1CRzZpf8rDmv9+fJ9zX7xwgkxQbugRefQf9S9WZZ7hURUy3b8Ddax4Fg7kV9MTQxijtjqab/WFBJDnCiEzvubenPk9XhGPARkWopnEMxvidO+MGQx1hCR8PGus2T75v0rTa5r+fJSIjZIIFC3Yjc/9NP7C645f8siNvCN61u4I/duWzXL+t304mL+nOomMgcZSW8XrxVpoM7hm+QltpgA+1loBBGY+VdbDZuQ90eN2g885PAkuZItk 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