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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4DEC4C433EF for ; Tue, 25 Jan 2022 03:43:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C26C06B0081; Mon, 24 Jan 2022 22:43:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BD6BA6B0083; Mon, 24 Jan 2022 22:43:37 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A9F6E6B0085; Mon, 24 Jan 2022 22:43:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0188.hostedemail.com [216.40.44.188]) by kanga.kvack.org (Postfix) with ESMTP id 995A16B0081 for ; Mon, 24 Jan 2022 22:43:37 -0500 (EST) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 594C295B05 for ; Tue, 25 Jan 2022 03:43:37 +0000 (UTC) X-FDA: 79067414874.10.129AB98 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by imf15.hostedemail.com (Postfix) with ESMTP id 76250A000F for ; Tue, 25 Jan 2022 03:43:36 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4JjXjM0MBdz9sNL; Tue, 25 Jan 2022 11:42:15 +0800 (CST) Received: from [10.174.177.76] (10.174.177.76) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 25 Jan 2022 11:43:33 +0800 Subject: Re: [PATCH v2] mm/damon: Remove redundant page validation To: Baolin Wang CC: , , , Andrew Morton References: <6d32f7d201b8970d53f51b6c5717d472aed2987c.1642386715.git.baolin.wang@linux.alibaba.com> From: Miaohe Lin Message-ID: <3db0e468-8713-b87b-1579-b79481e2c110@huawei.com> Date: Tue, 25 Jan 2022 11:43:33 +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: <6d32f7d201b8970d53f51b6c5717d472aed2987c.1642386715.git.baolin.wang@linux.alibaba.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected X-Rspam-User: nil X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 76250A000F X-Stat-Signature: n36prfaq5w7g3hrmfgkwti55qtjx89yn Authentication-Results: imf15.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf15.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com X-HE-Tag: 1643082216-286910 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 2022/1/17 10:34, Baolin Wang wrote: > It will never get a NULL page by pte_page() as discussed in thread [1], > thus remove the redundant page validation to fix below Smatch static > checker warning. > > mm/damon/vaddr.c:405 damon_hugetlb_mkold() > warn: 'page' can't be NULL. > > [1] https://lore.kernel.org/linux-mm/20220106091200.GA14564@kili/ > > Reported-by: Dan Carpenter > Signed-off-by: Baolin Wang > Reviewed-by: SeongJae Park LGTM. Thanks. Reviewed-by: Miaohe Lin > --- > Changes from v1: > - Improve the commit message suggested by SeongJae. > - Add reviewed-by tag from SeongJae. > --- > mm/damon/vaddr.c | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c > index 89b6468d..8a52e00 100644 > --- a/mm/damon/vaddr.c > +++ b/mm/damon/vaddr.c > @@ -402,9 +402,6 @@ static void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm, > pte_t entry = huge_ptep_get(pte); > struct page *page = pte_page(entry); > > - if (!page) > - return; > - > get_page(page); > > if (pte_young(entry)) { > @@ -564,9 +561,6 @@ static int damon_young_hugetlb_entry(pte_t *pte, unsigned long hmask, > goto out; > > page = pte_page(entry); > - if (!page) > - goto out; > - > get_page(page); > > if (pte_young(entry) || !page_is_idle(page) || >