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 7AD64C433F5 for ; Mon, 7 Mar 2022 01:14:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C05A98D0002; Sun, 6 Mar 2022 20:14:04 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BB56C8D0001; Sun, 6 Mar 2022 20:14:04 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A7D628D0002; Sun, 6 Mar 2022 20:14:04 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id 98C938D0001 for ; Sun, 6 Mar 2022 20:14:04 -0500 (EST) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 497BDA6C for ; Mon, 7 Mar 2022 01:14:04 +0000 (UTC) X-FDA: 79215818808.09.5D307A4 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf12.hostedemail.com (Postfix) with ESMTP id BE4E940004 for ; Mon, 7 Mar 2022 01:14:03 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id CD28A6100D; Mon, 7 Mar 2022 01:14:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A66EC340EC; Mon, 7 Mar 2022 01:14:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1646615642; bh=QyKxDogWlz/SuyW7MhbFirrHKLiSDLFcXuuEZeWILJk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=J8JpYYKq28vY5bwKo94x/S8nl6X0grr5MZgqOP8y8gdVhR7Q4/JKIsxdLjv0Jfin2 wDpyFHZOmXQZ5SDM7wq9846/YZ2Zx3hpj3hTX85mi9DHNHLwDtWrujPQl0RS0GIhEc ejjnW7EUn0nMN1PMSJDMGaaHzdbVs9GVfaGrjeWY= Date: Sun, 6 Mar 2022 17:14:00 -0800 From: Andrew Morton To: Miaohe Lin Cc: , , , , , , , , , , , , , , , , , Subject: Re: [PATCH 07/16] mm/migration: use helper macro min_t in do_pages_stat Message-Id: <20220306171400.a5cbab665b6338391447e541@linux-foundation.org> In-Reply-To: <20220304093409.25829-8-linmiaohe@huawei.com> References: <20220304093409.25829-1-linmiaohe@huawei.com> <20220304093409.25829-8-linmiaohe@huawei.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: BE4E940004 X-Stat-Signature: b6th9hyakpiyz1n4kngw61uiaudtppi8 Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=J8JpYYKq; dmarc=none; spf=pass (imf12.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-HE-Tag: 1646615643-368482 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 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(). --- 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, _