From patchwork Mon Jan 17 02:34:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolin Wang X-Patchwork-Id: 12714714 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 CE16BC433EF for ; Mon, 17 Jan 2022 02:34:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 083196B0074; Sun, 16 Jan 2022 21:34:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 032D16B0075; Sun, 16 Jan 2022 21:34:34 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E3C6A6B0078; Sun, 16 Jan 2022 21:34:34 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0117.hostedemail.com [216.40.44.117]) by kanga.kvack.org (Postfix) with ESMTP id D096E6B0074 for ; Sun, 16 Jan 2022 21:34:34 -0500 (EST) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 8260F18151398 for ; Mon, 17 Jan 2022 02:34:34 +0000 (UTC) X-FDA: 79038210468.21.5B61C53 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by imf09.hostedemail.com (Postfix) with ESMTP id 02C97140004 for ; Mon, 17 Jan 2022 02:34:32 +0000 (UTC) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0V1ziwmF_1642386869; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0V1ziwmF_1642386869) by smtp.aliyun-inc.com(127.0.0.1); Mon, 17 Jan 2022 10:34:29 +0800 From: Baolin Wang To: sj@kernel.org, akpm@linux-foundation.org Cc: baolin.wang@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] mm/damon: Remove redundant page validation Date: Mon, 17 Jan 2022 10:34:18 +0800 Message-Id: <6d32f7d201b8970d53f51b6c5717d472aed2987c.1642386715.git.baolin.wang@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 X-Stat-Signature: wx97cts978uzzzeepxdm85xdzkuy3okw Authentication-Results: imf09.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf09.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.130 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 02C97140004 X-HE-Tag: 1642386872-456793 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: 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 Acked-by: David Rientjes Acked-by: Souptick Joarder 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) ||