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 14FDAD64087 for ; Wed, 17 Dec 2025 07:32:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7950C6B00AD; Wed, 17 Dec 2025 02:32:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 73EBB6B00AF; Wed, 17 Dec 2025 02:32:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 66C6D6B00B0; Wed, 17 Dec 2025 02:32:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 527C26B00AD for ; Wed, 17 Dec 2025 02:32:27 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 1936F8B6A7 for ; Wed, 17 Dec 2025 07:32:27 +0000 (UTC) X-FDA: 84228145134.01.F60B575 Received: from out-180.mta0.migadu.com (out-180.mta0.migadu.com [91.218.175.180]) by imf04.hostedemail.com (Postfix) with ESMTP id 40D5D40004 for ; Wed, 17 Dec 2025 07:32:25 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=sWrtvrRI; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf04.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.180 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1765956745; a=rsa-sha256; cv=none; b=koEfDNEIUe+OMUWwGmqDUxzdaRh8v9Pme7jWPI4ZXPXv3bqTuIw/J1AwhjGeK537VAsmyq DGitbPn+NbFGokmtHiSw7XM3do5OoJmqMttTIxW7iT7u4fAvWCzVTLjNT1ouNK3szg//i3 Od07H7Z1nw5RrarM+C3ZhD/r/pKomzE= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=sWrtvrRI; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf04.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.180 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=1765956745; 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=XgHA+TVYxxe6Vv06rsmZd9zVObrCtofW37vIgARv2qc=; b=lGukjXn5sbNunyPmUUkL+VXP6En2J01cW7SxcuT4mRaTUPoEGgtDTIeqsvuwejdL0dZwcJ V9fenPfYlfj4c0sfFU064r9Y2r5mcfcKXMk+SvJj8/ctty+JPikfUNtbz2PhUmFFrLDL8w Fw7LAz8jS3qkoZJBNngLqsf+MgHg7uY= 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=1765956738; 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=XgHA+TVYxxe6Vv06rsmZd9zVObrCtofW37vIgARv2qc=; b=sWrtvrRIUjcLsV7Wz5k1ASxrUwoIXf5ObCdZlxnW7diW5X7mj4vFtrqgIm0bmWwwlrporg FvuQhwE+227JPy6VoGESBiGjDTkh1nwLknInGXf2rSOD4WFKaF/jNCHA5EV+7gOdbt70ce PqEwH7/QF0cw5Zu1jPS8S3uwLTa7hUM= 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, 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 Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Qi Zheng Subject: [PATCH v2 17/28] mm: thp: prevent memory cgroup release in folio_split_queue_lock{_irqsave}() Date: Wed, 17 Dec 2025 15:27:41 +0800 Message-ID: <4cb81ea06298a3b41873b7086bfc68f64b2ba8be.1765956025.git.zhengqi.arch@bytedance.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 40D5D40004 X-Stat-Signature: rqp5papq8r7dmym3n5zrq37ti6du1ecr X-Rspam-User: X-HE-Tag: 1765956745-589607 X-HE-Meta: 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 MFZ0KoUF tXeEsgUWeBu3dKhFduniD73fAArL0Y0v/0OPSHQA2CZ5V0awxc4jecBEMrWmk12vlEfNfo+x4ViyQx/FBHcy0noi6D19coDLVLKRz06/llzsfWFhNPYocPtiPlfenA4MVn2x4L1G20ARsFtXHrGy6Ey5OTSUjCcnNBGmyiJxMPAOydYURLYfngiWnQz9j7R+oS9yGaCk1jJDRbRVQFXjqYNuY3sHLdM/veXaooWdTgXuT2/y/d418BjS+mzaYwyP9kcBn 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: Qi Zheng In the near future, a folio will no longer pin its corresponding memory cgroup. To ensure safety, it will only be appropriate to hold the rcu read lock or acquire a reference to the memory cgroup returned by folio_memcg(), thereby preventing it from being released. In the current patch, the rcu read lock is employed to safeguard against the release of the memory cgroup in folio_split_queue_lock{_irqsave}(). Signed-off-by: Qi Zheng Reviewed-by: Harry Yoo --- mm/huge_memory.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 12b46215b30c1..b9e6855ec0b6a 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1154,13 +1154,25 @@ split_queue_lock_irqsave(int nid, struct mem_cgroup *memcg, unsigned long *flags static struct deferred_split *folio_split_queue_lock(struct folio *folio) { - return split_queue_lock(folio_nid(folio), folio_memcg(folio)); + struct deferred_split *queue; + + rcu_read_lock(); + queue = split_queue_lock(folio_nid(folio), folio_memcg(folio)); + rcu_read_unlock(); + + return queue; } static struct deferred_split * folio_split_queue_lock_irqsave(struct folio *folio, unsigned long *flags) { - return split_queue_lock_irqsave(folio_nid(folio), folio_memcg(folio), flags); + struct deferred_split *queue; + + rcu_read_lock(); + queue = split_queue_lock_irqsave(folio_nid(folio), folio_memcg(folio), flags); + rcu_read_unlock(); + + return queue; } static inline void split_queue_unlock(struct deferred_split *queue) -- 2.20.1