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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30CD3C433F5 for ; Tue, 29 Mar 2022 12:48:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236791AbiC2Mue (ORCPT ); Tue, 29 Mar 2022 08:50:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237948AbiC2MtZ (ORCPT ); Tue, 29 Mar 2022 08:49:25 -0400 Received: from mail-pl1-x631.google.com (mail-pl1-x631.google.com [IPv6:2607:f8b0:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E0A05227C5B for ; Tue, 29 Mar 2022 05:46:37 -0700 (PDT) Received: by mail-pl1-x631.google.com with SMTP id y6so14982483plg.2 for ; Tue, 29 Mar 2022 05:46:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=rxVMbNlsIDttgLsDQW9zlxLetSlVk0P6TXGtVI3cb6E=; b=PWILuP6rpZEDH4WXU2e7S+vFyN0Fd42Av4QSFBhoFmIXktyXkMalQjmfJgJCtM8Z8V wBmKN5HlT789q86wG5Ti6McqcFJAIm//30h6QDPaCxdL0FQhg34WUqwaTiOi9xuh38qF BvH3IqvHkHCT+ATftFblwjSqP28fmQ57WI+uLgVctAgpbYsIUOo8BjbrXfxGOOKVNUGH v7mU59TfKw6KEVVIlrsEvqgGZh+utDoUs1YtVukhXkCU+pjIGknph+lmuiH6B9gFMNLe i7EoRvF76t6zAAFg9hcbcPpapzur6bEU4wvTJrB4BTzru9Rdtu4jdZjpkcDmJSuA4acf 7+mA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=rxVMbNlsIDttgLsDQW9zlxLetSlVk0P6TXGtVI3cb6E=; b=u2wKTZJsLrj55qMm7hVp06uDbL4ykRaMXtBF+X7EOpVJ9XRr8w+WyRA5eE2UJqe6fd TrFKd911UFVs/erDOt0Lp2WZd496PlxBvfdHzj0Vx0D979hgaJFir67aEmAM3X51mh0z Z/ik7ETkx9kayUmc72C+Kp3Ijw7UBHa2JQTg7AYIP7AY+0t6V6vlv+h/46+JO351C7LX PfYqdLmMGQSgbU6ET5bhNWi5jIYVNQtxeCR88lq9dohk6bpq3BYIS3DeqoZtljdWsPHI Xf5f1VBKrSaEW/S/Jyzt+uwRslJpJqFo1IEG9/VBddJjxFEqneQkGQ82zv/ysmJEADe+ GIWw== X-Gm-Message-State: AOAM531R8fWNZ1d84erqJvdLV21FBzTnRiAlc2rU+poKoJXos8vWqsu0 84NpfDaXTpxxLD5jtt5+L7ZyKg== X-Google-Smtp-Source: ABdhPJwH1iXdVwT0nBUyiGXP5p/4Q0BR3MyTU6L9eyfTF2N9F7yM0gyokMxROV9mKgv2Fl8oSZnZ4w== X-Received: by 2002:a17:90a:840a:b0:1c9:5c4f:5e83 with SMTP id j10-20020a17090a840a00b001c95c4f5e83mr4376177pjn.144.1648557997386; Tue, 29 Mar 2022 05:46:37 -0700 (PDT) Received: from [192.168.1.100] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id nn7-20020a17090b38c700b001c9ba103530sm3042535pjb.48.2022.03.29.05.46.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 29 Mar 2022 05:46:36 -0700 (PDT) Message-ID: <2b37ce73-83dd-e572-9578-7bb045f1040b@kernel.dk> Date: Tue, 29 Mar 2022 06:46:35 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH -next RFC 2/6] block: refactor to split bio thoroughly Content-Language: en-US To: Yu Kuai , andriy.shevchenko@linux.intel.com, john.garry@huawei.com, ming.lei@redhat.com Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com References: <20220329094048.2107094-1-yukuai3@huawei.com> <20220329094048.2107094-3-yukuai3@huawei.com> From: Jens Axboe In-Reply-To: <20220329094048.2107094-3-yukuai3@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/29/22 3:40 AM, Yu Kuai wrote: > Currently, the splited bio is handled first, and then continue to split > the original bio. This patch tries to split the original bio thoroughly, > so that it can be known in advance how many tags will be needed. This makes the bio almost 10% bigger in size, which is NOT something that is just done casually and without strong reasoning. So please provide that, your commit message is completely missing justification for why this change is useful or necessary. A good commit always explains WHY the change needs to be made, yours is simply stating WHAT is being done. The latter can be gleaned from the code change anyway. -- Jens Axboe