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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2A93C001DF for ; Thu, 3 Aug 2023 07:13:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233037AbjHCHN2 (ORCPT ); Thu, 3 Aug 2023 03:13:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230096AbjHCHNZ (ORCPT ); Thu, 3 Aug 2023 03:13:25 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A75EFF for ; Thu, 3 Aug 2023 00:13:24 -0700 (PDT) Received: from dggpemm100001.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4RGg5Z18SSzrSCD; Thu, 3 Aug 2023 15:12:18 +0800 (CST) Received: from [10.174.177.243] (10.174.177.243) by dggpemm100001.china.huawei.com (7.185.36.93) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Thu, 3 Aug 2023 15:13:21 +0800 Message-ID: <001ee9b0-ea25-a896-e3ae-9a9b05a46546@huawei.com> Date: Thu, 3 Aug 2023 15:13:21 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.10.1 From: Kefeng Wang Subject: Re: [PATCH 1/4] mm: migrate: use a folio in add_page_for_migration() To: Matthew Wilcox CC: Andrew Morton , , , Huang Ying , David Hildenbrand References: <20230802095346.87449-1-wangkefeng.wang@huawei.com> <20230802095346.87449-2-wangkefeng.wang@huawei.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm100001.china.huawei.com (7.185.36.93) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/8/2 20:21, Matthew Wilcox wrote: > On Wed, Aug 02, 2023 at 05:53:43PM +0800, Kefeng Wang wrote: >> err = -EACCES; >> - if (page_mapcount(page) > 1 && !migrate_all) >> - goto out_putpage; >> + if (folio_estimated_sharers(folio) > 1 && !migrate_all) >> + goto out_putfolio; > > I do not think this is the correct change. Maybe leave this line > alone. Ok, I am aware of the discussion about this in other mail, will not change it(also the next two patch about this function), or wait the new work of David. > >> - if (PageHuge(page)) { >> - if (PageHead(page)) { >> - isolated = isolate_hugetlb(page_folio(page), pagelist); >> + if (folio_test_hugetlb(folio)) { >> + if (folio_test_large(folio)) { > > This makes no sense when you read it. All hugetlb folios are large, > by definition. Think about what this code used to do, and what it > should be changed to. hugetlb folio is self large folio, will drop redundant check