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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 16143C433DB for ; Wed, 24 Mar 2021 02:37:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 80CA66192E for ; Wed, 24 Mar 2021 02:37:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 80CA66192E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 073196B0290; Tue, 23 Mar 2021 22:37:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 00F8B6B0292; Tue, 23 Mar 2021 22:37:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DCB8E6B0294; Tue, 23 Mar 2021 22:37:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0100.hostedemail.com [216.40.44.100]) by kanga.kvack.org (Postfix) with ESMTP id BDE976B0290 for ; Tue, 23 Mar 2021 22:37:24 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 73FDC18020B1A for ; Wed, 24 Mar 2021 02:37:24 +0000 (UTC) X-FDA: 77953206408.02.33C1FF6 Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) by imf03.hostedemail.com (Postfix) with ESMTP id A0F76C0001F7 for ; Wed, 24 Mar 2021 02:37:22 +0000 (UTC) Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4F4slq5jC0zwPYV; Wed, 24 Mar 2021 10:35:19 +0800 (CST) Received: from [10.174.178.163] (10.174.178.163) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.498.0; Wed, 24 Mar 2021 10:37:14 +0800 Subject: Re: [PATCH v2 1/5] mm/migrate.c: remove unnecessary VM_BUG_ON_PAGE on putback_movable_page() To: Yang Shi CC: Andrew Morton , Jerome Glisse , Rafael Aquini , David Hildenbrand , Alistair Popple , "Linux Kernel Mailing List" , Linux MM References: <20210323135405.65059-1-linmiaohe@huawei.com> <20210323135405.65059-2-linmiaohe@huawei.com> From: Miaohe Lin Message-ID: Date: Wed, 24 Mar 2021 10:37:13 +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: [10.174.178.163] X-CFilter-Loop: Reflected X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: A0F76C0001F7 X-Stat-Signature: bb4fn95n59e93f5qirkmjtzsn1adxgry Received-SPF: none (huawei.com>: No applicable sender policy available) receiver=imf03; identity=mailfrom; envelope-from=""; helo=szxga05-in.huawei.com; client-ip=45.249.212.191 X-HE-DKIM-Result: none/none X-HE-Tag: 1616553442-375373 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 2021/3/24 1:58, Yang Shi wrote: > On Tue, Mar 23, 2021 at 6:54 AM Miaohe Lin wrote: >> >> The !PageLocked() check is implicitly done in PageMovable(). Remove this >> explicit one. > > TBH, I'm a little bit reluctant to have this kind change. If "locked" > check is necessary we'd better make it explicit otherwise just remove > it. > > And why not just remove all the 3 VM_BUG_ON_PAGE since > putback_movable_page() is just called by putback_movable_pages() and > we know the page is locked and both PageMovable and PageIsolated is > checked right before calling putback_movable_page(). > > And you also could make putback_movable_page() static. > Sounds good! Many thanks for your advice! >> Signed-off-by: Miaohe Lin >> --- >> mm/migrate.c | 1 - >> 1 file changed, 1 deletion(-) >> >> diff --git a/mm/migrate.c b/mm/migrate.c >> index 47df0df8f21a..facec65c7374 100644 >> --- a/mm/migrate.c >> +++ b/mm/migrate.c >> @@ -145,7 +145,6 @@ void putback_movable_page(struct page *page) >> { >> struct address_space *mapping; >> >> - VM_BUG_ON_PAGE(!PageLocked(page), page); >> VM_BUG_ON_PAGE(!PageMovable(page), page); >> VM_BUG_ON_PAGE(!PageIsolated(page), page); >> >> -- >> 2.19.1 >> > . >