Received: by 2002:a25:23cc:0:0:0:0:0 with SMTP id j195csp970065ybj; Tue, 5 May 2020 10:34:39 -0700 (PDT) X-Google-Smtp-Source: APiQypJVCHvLpSg+gFiVenA56dRnpJIiTc75T/qjXoizS6zYumvzGvP6Xr028SLtzDlByyXzRO4C X-Received: by 2002:aa7:d685:: with SMTP id d5mr3440001edr.340.1588700079201; Tue, 05 May 2020 10:34:39 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1588700079; cv=none; d=google.com; s=arc-20160816; b=XuttXczFIt+gD1YhDi15YGNg1OvvwasXpR82VnWOR83sXC8h0LZ7sLlh4+YpMOw66K Pm41rnzBElNXGTTApIM89FDtF9l/TM7QTic+xMCDrfYlDI997f211mhUzwTp06jY6nT1 uEfKGIyofJM+8pyUiTOifytrV70KQkNcRpZniB9FrrUxWoTJHZsuZI78vjvl68sUjH57 fFue1zQ2faLRPDQ5fybwwLmkfh63OFRANwPjYMrrgsxhMwRK7/VO+hAYyzLl9cW2mYxY GUqT+q3Nd4WsLRnDqg/n/86bgCMXDk9t8CqF4iCUfQnrdZ2BpQkCEjsksCD8OCL8pBO/ G6EQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:from:references:to:subject; bh=Yx2Uki1lG2kO0Y6eRKAI/Vzc2OwnFMWdt2eauyloWkk=; b=LptYQY+Oyew2oZI/FN+VXaizUgSTkv8jCGU7npBSdsCnaEwtkf2dYQxHbHexSd5evM gWYFxuI8sSO7xnaM+z7gQ2QA9kITeVFv1diToxhKQxqJd3qOiE+MvTcwR6YvcaNfPppZ /k8ufqwIMChoQlbeksZTsN25xsdUzu4Tiqf9MWom844pwfaqOcYp0ftd8vctgjGMP5QC KXsI/yLUhMBk2BancZCEqjfG2sFhfCdT8e6+/K3xEiHJcp2MmTBEyUtaudJTmVZdzPQH aQp78vy/JJgySCBmcDIIR0S+RERg3vpSJHVBUvBFlBEFE7/z8IFkX5B1vNCYpveNx4mB Z4Tg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id k14si1544953ejg.168.2020.05.05.10.34.15; Tue, 05 May 2020 10:34:39 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730650AbgEERcj (ORCPT + 99 others); Tue, 5 May 2020 13:32:39 -0400 Received: from smtp.hosts.co.uk ([85.233.160.19]:46352 "EHLO smtp.hosts.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729709AbgEERcj (ORCPT ); Tue, 5 May 2020 13:32:39 -0400 Received: from [81.153.126.158] (helo=[192.168.1.225]) by smtp.hosts.co.uk with esmtpa (Exim) (envelope-from ) id 1jW1Qq-0006Ej-Em; Tue, 05 May 2020 18:32:36 +0100 Subject: Re: [PATCH 0/4] eliminate SECTOR related magic numbers and duplicated conversions To: Zhen Lei , 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> From: antlists Message-ID: Date: Tue, 5 May 2020 18:32:36 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200505115543.1660-1-thunder.leizhen@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/05/2020 12:55, Zhen Lei wrote: > When I studied the code of mm/swap, I found "1 << (PAGE_SHIFT - 9)" appears > many times. So I try to clean up it. > > 1. Replace "1 << (PAGE_SHIFT - 9)" or similar with SECTORS_PER_PAGE > 2. Replace "PAGE_SHIFT - 9" with SECTORS_PER_PAGE_SHIFT > 3. Replace "9" with SECTOR_SHIFT > 4. Replace "512" with SECTOR_SIZE Naive question - what is happening about 4096-byte sectors? Do we need to forward-plan? Cheers, Wol