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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 22B80C4363A for ; Thu, 29 Oct 2020 14:11:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB2AE2076B for ; Thu, 29 Oct 2020 14:11:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="B21xMtqo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726361AbgJ2OLq (ORCPT ); Thu, 29 Oct 2020 10:11:46 -0400 Received: from mout.gmx.net ([212.227.15.15]:46395 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725300AbgJ2OLp (ORCPT ); Thu, 29 Oct 2020 10:11:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1603980702; bh=NaPOGUl+Bx9sL8dfYOtUu1WswgL6sp7do7P1GY+PsJE=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=B21xMtqojmewDGlic6s3R8VfIR1ibIZJ9HkPuTkyY/PVAKr8r0Lp6lZLCdvyCm686 dfLaXBPTcira3/+ajtvOjhiBG/E7JekEp3ok+kMpPmLNij5xuPS0t1oRgV6UyqAwSH U9uLiYID8K+iG6Mgm//HD8F+r/ftzSnWorgBjsss= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx004 [212.227.17.184]) with ESMTPSA (Nemesis) id 1MuDc7-1kFUhc2Ktx-00ua50; Thu, 29 Oct 2020 15:11:42 +0100 Subject: Re: [PATCH v2 3/3] btrfs: file-item: refactor btrfs_lookup_bio_sums() to handle out-of-order bvecs To: dsterba@suse.cz, Nikolay Borisov , Qu Wenruo , linux-btrfs@vger.kernel.org References: <20201029071218.49860-1-wqu@suse.com> <20201029071218.49860-4-wqu@suse.com> <765375f6-7c4f-e9d9-f0f5-3de9bac74cce@suse.com> <55275e3c-1828-7180-e902-8344a571516e@gmx.com> <20201029135415.GK6756@twin.jikos.cz> From: Qu Wenruo Autocrypt: addr=quwenruo.btrfs@gmx.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20201029135415.GK6756@twin.jikos.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:Y6tSifGfDG9may9s4kit+pK8BaLDozAOUf1mapY05EoILzhDGPQ N0ON0EFP+teNYg6USiHNOE+jsXVF/HzyB5wAd7yq0rznQDc0eYwVojnFvsVdUIdNm36iy2W 2lT7YNBEuPi1c2Lhv9jV9xVTaQtdRAx+g+FZ6GQmPL2Dih3/H4QB/b6xhmNQeQ1LieoiQtd gW6hB5S7hjIKprZgolpqg== X-UI-Out-Filterresults: notjunk:1;V03:K0:UJEsqEXzWIw=:tPJ08Ue04v+BqVY+icOoOl bgI8ek0SzcAa6wGf0vt0J0RtZj9z2uDIRWbK/4WxcNUPQ42Vbc5BBRxkgRLNFivsILLlD8tF9 I2dhauq/377CZUVaKYCnR9+l1itoaTZD3vbS+9GgJMIXNDuRsc1TG63ZcSsQhXsMHzUdMifNr 6gRzsqKl8F45QN51HP9aw1vqwmoyPcKvaI0v60TDxzFOraPCj56RjIP1XoHPRo2o6aB2EQopj fnfE9W7sKlrfv/nju706KDO4U0d5WPlbWxe8jxaZJgEygowt0LD4MhBnzbXQl0/fd/qAl4FJC 6Xi8H5CfuViN7zxqwckoVDxLVNSu5pOrnkqUtM6KKqZ2JefWSWCnmIUiSYxE2m65wz00PvEQ5 vnp8n0vc/oz/wSu15vD82IVpRjaRNMU99ZXL8wl3lb0MN2sUVKWdSaKF1Uc6eoAmxlRASManp CVTlc2eb4huc1ic86m0dmd4CfTnbRQazUUgt5sNoSAG/AhGykjKykpt7qCF5sccJFZlWUtJvJ pWo3xDQb0B/xvst/SI9uM8jDgz9zjq3oke5oCLMgaYhlntTFHkMIg3tB7eB9Gkty5+sbpdO5o rr6fJhGM8iOpLVw+kvDvqrypKhSIoid4E4KvevV3Fr0A0fn//le3LAuOtoGO34YF/5EiFPthq v165Nzzqa9AdObRShX+L9ISDm8ty9oM0Yfy1+bPmQxjN9Cq1zaUcCflLTwyaYTIjkAllvyObr G0tymS4herFepp0EX0xIvSEAd/D/OOLHYysGSdKyCqBtvichbono9eK+Q7Pvx1jTbhwL6bTUk uwm7BuR0TJSZvVfoRmmNMn1mL7RFSy5hXoAuhQkOOAEB3APSTXWiXbPTy84US6320j0EecfCX 7iZEqhirxIMz0elm2UmA== Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2020/10/29 =E4=B8=8B=E5=8D=889:54, David Sterba wrote: > On Thu, Oct 29, 2020 at 08:43:12PM +0800, Qu Wenruo wrote: >> On 2020/10/29 =E4=B8=8B=E5=8D=887:50, Nikolay Borisov wrote: >>> On 29.10.20 =D0=B3. 9:12 =D1=87., Qu Wenruo wrote: >>>> +{ >>>> + struct btrfs_csum_item *item =3D NULL; >>>> + struct btrfs_key key; >>>> + u32 csum_size =3D btrfs_super_csum_size(fs_info->super_copy); >>> >>> nit: Why u32, btrfs_super_csum_size is defined as returning 'int', >>> however this function is really returning u16 since "struct btrfs_csum= s" >>> is defined as u16. >> >> It was misguided by u32 from btrfs super block, where sectorsize, >> nodesize are all u32. >> >> Any recommendation on this? Just u16 for csum_size or follow >> nodesize/sectorsize to use u32? > > u32 is ok, this generates a bit better assembly than u16. I'm about to > send the patchset lifting it to fs_info and it uses u32. > BTW, if you're going to change that, what about adding some thing like nodesize_bits/sectorsize_bits/csumsize_bits? There are a lot of locations that u64/u32 leads to 32bit compiling error, and a bit shifting would be a much better solution than div_u64() macro. Thanks, Qu