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 91B8CC4338F for ; Fri, 23 Jul 2021 07:13:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C97360EE2 for ; Fri, 23 Jul 2021 07:13:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234196AbhGWGcw (ORCPT ); Fri, 23 Jul 2021 02:32:52 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:12242 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234152AbhGWGcw (ORCPT ); Fri, 23 Jul 2021 02:32:52 -0400 Received: from dggeme703-chm.china.huawei.com (unknown [172.30.72.53]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4GWL466T0Mz1CLTq; Fri, 23 Jul 2021 15:07:34 +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 15:13:23 +0800 Subject: Re: linux-5.13.2: warning from kernel/rcu/tree_plugin.h:359 To: Greg KH CC: Matthew Wilcox , 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: <2237123.PRLUojbHBq@natalenko.name> <01fef2db-bd7e-12b6-ec21-2addd02e7062@huawei.com> From: Miaohe Lin Message-ID: Date: Fri, 23 Jul 2021 15:13:22 +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: dggems705-chm.china.huawei.com (10.3.19.182) To dggeme703-chm.china.huawei.com (10.1.199.99) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org On 2021/7/23 15:02, Greg KH wrote: > On Fri, Jul 23, 2021 at 09:51:09AM +0800, Miaohe Lin wrote: >> 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. > > 5.12 is now end-of-life, it's not being touched anymore, and no one > should continue to use it. > > thanks, I see! Many thanks for your kindly explanation! :) > > greg k-h > . >