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=-2.3 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 DE643C433DF for ; Fri, 15 May 2020 06:43:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A54232065F for ; Fri, 15 May 2020 06:43:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A54232065F 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 3D23090000C; Fri, 15 May 2020 02:43:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 380858E0005; Fri, 15 May 2020 02:43:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 295B190000C; Fri, 15 May 2020 02:43:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0022.hostedemail.com [216.40.44.22]) by kanga.kvack.org (Postfix) with ESMTP id 109438E0005 for ; Fri, 15 May 2020 02:43:35 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id BBD71180AD80F for ; Fri, 15 May 2020 06:43:34 +0000 (UTC) X-FDA: 76818012348.24.milk13_20ea3e371117 X-HE-Tag: milk13_20ea3e371117 X-Filterd-Recvd-Size: 2651 Received: from huawei.com (szxga07-in.huawei.com [45.249.212.35]) by imf27.hostedemail.com (Postfix) with ESMTP for ; Fri, 15 May 2020 06:43:34 +0000 (UTC) Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 443D0F559CF58DF50670; Fri, 15 May 2020 14:42:48 +0800 (CST) Received: from [127.0.0.1] (10.166.215.55) by DGGEMS401-HUB.china.huawei.com (10.3.19.201) with Microsoft SMTP Server id 14.3.487.0; Fri, 15 May 2020 14:42:46 +0800 Subject: Re: [PATCH v2 06/10] mm/swap: use npage_to_sectors() and PAGE_SECTORS to clean up code To: Matthew Wilcox CC: Minchan Kim , Nitin Gupta , "Sergey Senozhatsky" , Jens Axboe , Coly Li , Kent Overstreet , Alasdair Kergon , Mike Snitzer , linux-block , "Andrew Morton" , linux-mm , dm-devel , Song Liu , linux-raid , linux-kernel References: <20200507075100.1779-1-thunder.leizhen@huawei.com> <20200507075100.1779-7-thunder.leizhen@huawei.com> <20200515041456.GD16070@bombadil.infradead.org> From: "Leizhen (ThunderTown)" Message-ID: <85ea7c5e-9879-8aa4-c0f4-c60f107d63e3@huawei.com> Date: Fri, 15 May 2020 14:42:44 +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: <20200515041456.GD16070@bombadil.infradead.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.166.215.55] X-CFilter-Loop: Reflected 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 2020/5/15 12:14, Matthew Wilcox wrote: > On Thu, May 07, 2020 at 03:50:56PM +0800, Zhen Lei wrote: >> +++ b/mm/page_io.c >> @@ -38,7 +38,7 @@ static struct bio *get_swap_bio(gfp_t gfp_flags, >> >> bio->bi_iter.bi_sector = map_swap_page(page, &bdev); >> bio_set_dev(bio, bdev); >> - bio->bi_iter.bi_sector <<= PAGE_SHIFT - 9; >> + bio->bi_iter.bi_sector *= PAGE_SECTORS; >> bio->bi_end_io = end_io; > > This just doesn't look right. Why is map_swap_page() returning a sector_t > which isn't actually a sector_t? I try to understand map_swap_page(). Here maybe a bug. Otherwise, it would be better to add a temporary variable to cache the return value of map_swap_page(page, &bdev). > > > . >