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 X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 517E5C432BE for ; Fri, 23 Jul 2021 01:51:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A24560EB5 for ; Fri, 23 Jul 2021 01:51:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233122AbhGWBKj (ORCPT ); Thu, 22 Jul 2021 21:10:39 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:12240 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230318AbhGWBKi (ORCPT ); Thu, 22 Jul 2021 21:10:38 -0400 Received: from dggeme703-chm.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4GWBwL0q2xz1CMrc; Fri, 23 Jul 2021 09:45:22 +0800 (CST) Received: from [10.174.177.180] (10.174.177.180) by dggeme703-chm.china.huawei.com (10.1.199.99) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Fri, 23 Jul 2021 09:51:10 +0800 Subject: Re: linux-5.13.2: warning from kernel/rcu/tree_plugin.h:359 To: Greg KH , Matthew Wilcox CC: Zhouyi Zhou , Chris Clayton , Oleksandr Natalenko , Boqun Feng , , linux-kernel , , Chris Rankin , Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , rcu , Andrew Morton , Linux-MM , "Huang, Ying" References: <5812280.fcLxn8YiTP@natalenko.name> <2237123.PRLUojbHBq@natalenko.name> From: Miaohe Lin Message-ID: <01fef2db-bd7e-12b6-ec21-2addd02e7062@huawei.com> Date: Fri, 23 Jul 2021 09:51:09 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.180] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggeme703-chm.china.huawei.com (10.1.199.99) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/7/22 22:00, Greg KH wrote: > On Thu, Jul 22, 2021 at 03:26:52PM +0200, Greg KH wrote: >> On Thu, Jul 22, 2021 at 01:36:02PM +0100, Matthew Wilcox wrote: >>> On Thu, Jul 22, 2021 at 04:57:57PM +0800, Zhouyi Zhou wrote: >>>> Thanks for reviewing, >>>> >>>> What I have deduced from the dmesg is: >>>> In function do_swap_page, >>>> after invoking >>>> 3385 si = get_swap_device(entry); /* rcu_read_lock */ >>>> and before >>>> 3561 out: >>>> 3562 if (si) >>>> 3563 put_swap_device(si); >>>> The thread got scheduled out in >>>> 3454 locked = lock_page_or_retry(page, vma->vm_mm, vmf->flags); >>>> >>>> I am only familiar with Linux RCU subsystem, hope mm people can solve our >>>> confusions. >>> >>> I don't understamd why you're still talking. The problem is understood. >>> You need to revert the unnecessary backport of 2799e77529c2 and >>> 2efa33fc7f6e >> >> Sorry for the delay, will go do so in a minute... > > Both now reverted from 5.10.y and 5.13.y. > I browsed my previous backport notifying email and found that these two patches are also backported into 5.12. And it seems it's missed. Thanks. > thanks, > > greg k-h > . >