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 29EACC433FE for ; Mon, 7 Mar 2022 11:51:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238489AbiCGLwE (ORCPT ); Mon, 7 Mar 2022 06:52:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53788 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232775AbiCGLwD (ORCPT ); Mon, 7 Mar 2022 06:52:03 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 200F26E781 for ; Mon, 7 Mar 2022 03:51:08 -0800 (PST) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4KBxZw6C8gzdfwr; Mon, 7 Mar 2022 19:49:44 +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; Mon, 7 Mar 2022 19:51:05 +0800 Subject: Re: [PATCH 07/16] mm/migration: use helper macro min_t in do_pages_stat To: Andrew Morton CC: , , , , , , , , , , , , , , , , , References: <20220304093409.25829-1-linmiaohe@huawei.com> <20220304093409.25829-8-linmiaohe@huawei.com> <20220306171400.a5cbab665b6338391447e541@linux-foundation.org> From: Miaohe Lin Message-ID: Date: Mon, 7 Mar 2022 19:51:04 +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: <20220306171400.a5cbab665b6338391447e541@linux-foundation.org> 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/3/7 9:14, Andrew Morton wrote: > On Fri, 4 Mar 2022 17:34:00 +0800 Miaohe Lin wrote: > >> We could use helper macro min_t to help set the chunk_nr to simplify >> the code. >> >> ... >> >> --- a/mm/migrate.c >> +++ b/mm/migrate.c >> @@ -1858,9 +1858,7 @@ static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages, >> while (nr_pages) { >> unsigned long chunk_nr; >> >> - chunk_nr = nr_pages; >> - if (chunk_nr > DO_PAGES_STAT_CHUNK_NR) >> - chunk_nr = DO_PAGES_STAT_CHUNK_NR; >> + chunk_nr = min_t(unsigned long, nr_pages, DO_PAGES_STAT_CHUNK_NR); >> >> if (in_compat_syscall()) { >> if (get_compat_pages_array(chunk_pages, pages, > > Getting the types correct is better than using min_t(). > Looks good. Many thanks for your suggestion. Will do it in v2. Thanks. > --- a/mm/migrate.c~mm-migration-use-helper-macro-min_t-in-do_pages_stat-fix > +++ a/mm/migrate.c > @@ -1844,14 +1844,12 @@ static int do_pages_stat(struct mm_struc > const void __user * __user *pages, > int __user *status) > { > -#define DO_PAGES_STAT_CHUNK_NR 16 > +#define DO_PAGES_STAT_CHUNK_NR 16UL > const void __user *chunk_pages[DO_PAGES_STAT_CHUNK_NR]; > int chunk_status[DO_PAGES_STAT_CHUNK_NR]; > > while (nr_pages) { > - unsigned long chunk_nr; > - > - chunk_nr = min_t(unsigned long, nr_pages, DO_PAGES_STAT_CHUNK_NR); > + unsigned long chunk_nr = min(nr_pages, DO_PAGES_STAT_CHUNK_NR); > > if (in_compat_syscall()) { > if (get_compat_pages_array(chunk_pages, pages, > _ > > . >