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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 EF355C47247 for ; Wed, 6 May 2020 01:33:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BAAAE20735 for ; Wed, 6 May 2020 01:33:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BAAAE20735 Authentication-Results: mail.kernel.org; dmarc=none (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 4391A8E0005; Tue, 5 May 2020 21:33:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3C2BD8E0003; Tue, 5 May 2020 21:33:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 28A2D8E0005; Tue, 5 May 2020 21:33:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0237.hostedemail.com [216.40.44.237]) by kanga.kvack.org (Postfix) with ESMTP id 0D5918E0003 for ; Tue, 5 May 2020 21:33:58 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id BE960824CA22 for ; Wed, 6 May 2020 01:33:57 +0000 (UTC) X-FDA: 76784572914.14.flag42_79d1d853a5f14 X-HE-Tag: flag42_79d1d853a5f14 X-Filterd-Recvd-Size: 2654 Received: from huawei.com (szxga04-in.huawei.com [45.249.212.190]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Wed, 6 May 2020 01:33:57 +0000 (UTC) Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 44882CD09A619D1254D8; Wed, 6 May 2020 09:33:53 +0800 (CST) Received: from [127.0.0.1] (10.166.215.55) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.487.0; Wed, 6 May 2020 09:33:52 +0800 Subject: Re: [PATCH 2/4] mm/swap: use SECTORS_PER_PAGE_SHIFT to clean up code To: Matthew Wilcox CC: Minchan Kim , Nitin Gupta , "Sergey Senozhatsky" , Jens Axboe , linux-block , Andrew Morton , linux-mm , Alasdair Kergon , Mike Snitzer , dm-devel , Song Liu , linux-raid , linux-kernel References: <20200505115543.1660-1-thunder.leizhen@huawei.com> <20200505115543.1660-3-thunder.leizhen@huawei.com> <20200505172520.GI16070@bombadil.infradead.org> From: "Leizhen (ThunderTown)" Message-ID: <32ba9907-60ad-27c0-c565-e7b5c80ab03c@huawei.com> Date: Wed, 6 May 2020 09:33:50 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20200505172520.GI16070@bombadil.infradead.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US X-Originating-IP: [10.166.215.55] X-CFilter-Loop: Reflected Content-Transfer-Encoding: quoted-printable 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 2020/5/6 1:25, Matthew Wilcox wrote: > On Tue, May 05, 2020 at 07:55:41PM +0800, Zhen Lei wrote: >> +++ b/mm/swapfile.c >> @@ -177,8 +177,8 @@ static int discard_swap(struct swap_info_struct *s= i) >> =20 >> /* Do not discard the swap header page! */ >> se =3D first_se(si); >> - start_block =3D (se->start_block + 1) << (PAGE_SHIFT - 9); >> - nr_blocks =3D ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9); >> + start_block =3D (se->start_block + 1) << SECTORS_PER_PAGE_SHIFT; >> + nr_blocks =3D ((sector_t)se->nr_pages - 1) << SECTORS_PER_PAGE_SHIFT= ; >=20 > Thinking about this some more, wouldn't this look better? >=20 > start_block =3D page_sectors(se->start_block + 1); > nr_block =3D page_sectors(se->nr_pages - 1); >=20 OK=EF=BC=8CThat's fine, it's clearer. And in this way, there won't be mor= e than 80 columns. >=20 > . >=20