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 2D015E6B277 for ; Tue, 23 Dec 2025 06:14:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8E2D26B0005; Tue, 23 Dec 2025 01:14:24 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 890276B0089; Tue, 23 Dec 2025 01:14:24 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 79C516B008A; Tue, 23 Dec 2025 01:14:24 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 65FF36B0005 for ; Tue, 23 Dec 2025 01:14:24 -0500 (EST) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 0F02DB9B04 for ; Tue, 23 Dec 2025 06:14:24 +0000 (UTC) X-FDA: 84249721248.06.FAB6042 Received: from out-181.mta0.migadu.com (out-181.mta0.migadu.com [91.218.175.181]) by imf30.hostedemail.com (Postfix) with ESMTP id 3DCA280007 for ; Tue, 23 Dec 2025 06:14:22 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=p3pNAUjj; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf30.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.181 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1766470462; a=rsa-sha256; cv=none; b=v9PuoDO38yfUCKc/K317IKDtlJxh/cYUlQQIg8IHXBLHbMSPkym5bc29Pno800O+BTYpPr PTZdcotLlWgimBwNIcTJcNOS+N6eDR75skQkb7YfBkXd45MHDE7ytSgI2fHC+B/rNbmQ4y zMlCXis94/I2H73AS6d7xtz+v8vpYcM= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=p3pNAUjj; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf30.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.181 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=1766470462; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=v1Vxe9QHr773cXPHburX7fEkwO6UQV/y6BuQFvRR+UI=; b=VYsMOYFFLunS15xH3Csl8jAqSbLs15E2vi4CIM9qQZj5RkKtIJELb5KmzGNFS1di0UpapP X9bW0wzbVJf5JxVqXCKD3QxJexGgXDSy2FlCSNiu/dYT6GAf5NqZqL8rNQP7kzJ0yewo93 1rSfvI21fIFzzCA2xUJakfUDzj33+9g= Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1766470460; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=v1Vxe9QHr773cXPHburX7fEkwO6UQV/y6BuQFvRR+UI=; b=p3pNAUjj1hv8lsweRgKt7TABdptgSaVSplZqD1MmYcacqWp56Jo6BybVFtDaZv6+69kQnc oEJurwFFBic9lI2wg4vy0AVYfl1Ixwo5Mq6tVEPaKXdhWG1WFv+xQ0BI3dBp4RgSvRuTly bbrH8k2y4SlComNwLN0LoW3Q2PL0ZVo= Date: Tue, 23 Dec 2025 14:14:09 +0800 MIME-Version: 1.0 Subject: Re: [PATCH v2 23/28] mm: memcontrol: prepare for reparenting LRU pages for lruvec lock To: Shakeel Butt Cc: hannes@cmpxchg.org, hughd@google.com, mhocko@suse.com, roman.gushchin@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, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Muchun Song , Qi Zheng References: <6d643ea41dd89134eb3c7af96f5bfb3531da7aa7.1765956026.git.zhengqi.arch@bytedance.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Qi Zheng In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: 3DCA280007 X-Rspamd-Server: rspam03 X-Stat-Signature: 3hsucerz97my76uzn4s3ngacjt6bboqj X-Rspam-User: X-HE-Tag: 1766470462-128533 X-HE-Meta: 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 9X6/O1FA 7VJ2V8BmxGmSc4OxYfXPhfheuRokcIvSGQNQvzSyyA2efjNw18IavbPgrM98zz82FLe11/Pa/nAc+J5VLMJIEW3J6N2drGdQT4qaW+us7WvPaBb9T8/j2l4f0bqyILO8nd+UWrAx0S5ulld9BMIFQperVBL9zP15py2YgR+ghoV0srDa6AtrkerDtZhKqjqKRaJmho71NB48RVS9ccODClk/Inw== 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: On 12/20/25 10:03 AM, Shakeel Butt wrote: > On Wed, Dec 17, 2025 at 03:27:47PM +0800, Qi Zheng wrote: >> @@ -1232,14 +1221,20 @@ struct lruvec *folio_lruvec_lock(struct folio *folio) >> * - folio frozen (refcount of 0) >> * >> * Return: The lruvec this folio is on with its lock held and interrupts >> - * disabled. >> + * disabled and rcu read lock held. >> */ >> struct lruvec *folio_lruvec_lock_irq(struct folio *folio) >> { >> - struct lruvec *lruvec = folio_lruvec(folio); >> + struct lruvec *lruvec; >> >> + rcu_read_lock(); >> +retry: >> + lruvec = folio_lruvec(folio); >> spin_lock_irq(&lruvec->lru_lock); >> - lruvec_memcg_debug(lruvec, folio); >> + if (unlikely(lruvec_memcg(lruvec) != folio_memcg(folio))) { >> + spin_unlock_irq(&lruvec->lru_lock); >> + goto retry; >> + } > > So after this patch, all folio_lruvec_lock_irq() calls should be paired > with lruvec_unlock_irq() but lru_note_cost_refault() is calling > folio_lruvec_lock_irq() without the paired lruvec_unlock_irq(). It is > using lru_note_cost_unlock_irq() for unlocking lru lock and thus rcu > read unlock is missed. Indeed. Will fix in the next version. > > Beside fixing this, I would suggest to add __acquire()/__release() tags > for both lru lock and rcu for all these functions. OK, will do. Thanks, Qi >