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 1C564C4332F for ; Thu, 3 Nov 2022 19:32:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229700AbiKCTcz (ORCPT ); Thu, 3 Nov 2022 15:32:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229485AbiKCTcy (ORCPT ); Thu, 3 Nov 2022 15:32:54 -0400 Received: from mail-pg1-f171.google.com (mail-pg1-f171.google.com [209.85.215.171]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFF3E1CA for ; Thu, 3 Nov 2022 12:32:53 -0700 (PDT) Received: by mail-pg1-f171.google.com with SMTP id 128so2558341pga.1 for ; Thu, 03 Nov 2022 12:32:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=jlfPxhhLvEQn6lsaScftYKSX3SGTGT53qHnShoVMGMg=; b=CSrK7kYy7Yk8pB31ux50J1RQ8a+4wlp6WCoqCPcHKUsRgaUOVuZ+wSz12HTO+wwFZe GHklo2fGnCqRRYqgUpexv+5QyudjCzPHQSqeAGgMVbik/BcBwd/g5UqehZGLCIqNVu8+ IRZzNdQc7jnZ6VOP5cIie3w4ulvQCL/3toraN2z/rFgBns+0cnal4DneDjqhXcyJp02E LNoW6OvNdu7q1o+mFjH5JFnQmy4LhubvHcoP3T16hIO23Q5R5d38/b7Xh/5G7x+IMoue Z2Z2G53/EkH87i6HgQv9GjCny10SxfXQIys3Xt2ImFAhCK0InnF1qCMkrGG5DGeMUXwI Rfgw== X-Gm-Message-State: ACrzQf0Cax6kBi8B2X6+CsOr2PcdxbS95urXzC4yKx5WEHJJieaZI13L nelNH+yzsY0f8UxJeMT6snc= X-Google-Smtp-Source: AMsMyM4qB4mdwznCQnp+XC/bGXo7knYQLUQ7gsbLuni/AkKQcHDKpyw0aQBhDB/J3si+YusJ82Ue0g== X-Received: by 2002:a05:6a00:190a:b0:56c:123e:3e61 with SMTP id y10-20020a056a00190a00b0056c123e3e61mr31743311pfi.47.1667503973229; Thu, 03 Nov 2022 12:32:53 -0700 (PDT) Received: from ?IPV6:2620:15c:211:201:881a:8a80:fdae:8683? ([2620:15c:211:201:881a:8a80:fdae:8683]) by smtp.gmail.com with ESMTPSA id f5-20020aa79685000000b0056bb36c047asm1115092pfk.105.2022.11.03.12.32.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 03 Nov 2022 12:32:52 -0700 (PDT) Message-ID: <89172337-0698-e3ef-611f-5487f9ef53bb@acm.org> Date: Thu, 3 Nov 2022 12:32:50 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.0 Subject: Re: [PATCH 06/10] block: Fix the number of segment calculations Content-Language: en-US To: Ming Lei Cc: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig , Keith Busch References: <20221019222324.362705-1-bvanassche@acm.org> <20221019222324.362705-7-bvanassche@acm.org> <934d8e30-8629-d598-0214-987580c349b8@acm.org> From: Bart Van Assche In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 11/1/22 18:22, Ming Lei wrote: > On Tue, Nov 01, 2022 at 10:23:32AM -0700, Bart Van Assche wrote: >> On 10/19/22 15:23, Bart Van Assche wrote: >>> Since multi-page bvecs are supported there can be multiple segments per >>> bvec (see also bvec_split_segs()). Hence this patch that calculates the >>> number of segments per bvec instead of assuming that there is only one >>> segment per bvec. >> >> (replying to my own email) >> >> Hi Ming, >> >> Do you agree that this patch fixes a bug introduced by the multi-page bvec >> code and also that it is required even if the segment size is larger than >> the page size? > > No, multi-age bvec is only applied on normal IO bvec, and it isn't used > in bio_add_pc_page(), so there isn't such issue in blk_rq_append_bio(), > that is why we needn't to split passthrough bio. Hi Ming, Thanks for the feedback. I will fix the description of this patch. Bart.