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=-5.3 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 352CAC433B4 for ; Tue, 13 Apr 2021 19:24:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ACE71613B6 for ; Tue, 13 Apr 2021 19:24:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ACE71613B6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0C7876B0070; Tue, 13 Apr 2021 15:24:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 077C56B0072; Tue, 13 Apr 2021 15:24:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E5A426B0073; Tue, 13 Apr 2021 15:24:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0050.hostedemail.com [216.40.44.50]) by kanga.kvack.org (Postfix) with ESMTP id C67BE6B0070 for ; Tue, 13 Apr 2021 15:24:27 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 77245824934B for ; Tue, 13 Apr 2021 19:24:27 +0000 (UTC) X-FDA: 78028320174.23.54955F2 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by imf08.hostedemail.com (Postfix) with ESMTP id B2E9680192C0 for ; Tue, 13 Apr 2021 19:24:13 +0000 (UTC) IronPort-SDR: kaRU3z68alFYN8d4+zWJeNx0huq3sLIQfvF2fhAd797+8U3ZFyQrNgbA7G3Eq/YjdOD6vA3uKI RgNxM7zzvxPg== X-IronPort-AV: E=McAfee;i="6200,9189,9953"; a="191299295" X-IronPort-AV: E=Sophos;i="5.82,220,1613462400"; d="scan'208";a="191299295" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2021 12:24:19 -0700 IronPort-SDR: 2yoHeovCI3a6lwDX15UkiP+br97TlGA4ZUuiWGsE3zX4jQw45Wy2CkHVPqR70e+/2rirbrrRrU RZUTBeZgmudw== X-IronPort-AV: E=Sophos;i="5.82,220,1613462400"; d="scan'208";a="443539373" Received: from schen9-mobl.amr.corp.intel.com ([10.209.18.184]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Apr 2021 12:24:17 -0700 Subject: Re: [PATCH 2/5] swap: fix do_swap_page() race with swapoff To: "Huang, Ying" , Miaohe Lin Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, mhocko@suse.com, iamjoonsoo.kim@lge.com, vbabka@suse.cz, alex.shi@linux.alibaba.com, willy@infradead.org, minchan@kernel.org, richard.weiyang@gmail.com, hughd@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20210408130820.48233-1-linmiaohe@huawei.com> <20210408130820.48233-3-linmiaohe@huawei.com> <87o8ejug76.fsf@yhuang6-desk1.ccr.corp.intel.com> From: Tim Chen Message-ID: Date: Tue, 13 Apr 2021 12:24:15 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <87o8ejug76.fsf@yhuang6-desk1.ccr.corp.intel.com> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Stat-Signature: podhydcw4y5i5bjx6ripygumz6wwzx5c X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: B2E9680192C0 Received-SPF: none (linux.intel.com>: No applicable sender policy available) receiver=imf08; identity=mailfrom; envelope-from=""; helo=mga11.intel.com; client-ip=192.55.52.93 X-HE-DKIM-Result: none/none X-HE-Tag: 1618341853-666906 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: On 4/12/21 6:27 PM, Huang, Ying wrote: > > This isn't the commit that introduces the race. You can use `git blame` > find out the correct commit. For this it's commit 0bcac06f27d7 "mm, > swap: skip swapcache for swapin of synchronous device". > > And I suggest to merge 1/5 and 2/5 to make it easy to get the full > picture. I'll suggest make fix to do_swap_page race with get/put_swap_device as a first patch. Then the per_cpu_ref stuff in patch 1 and patch 2 can be combined together. Tim