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=-4.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 74A6FC433B4 for ; Mon, 10 May 2021 07:47:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 370CD61432 for ; Mon, 10 May 2021 07:47:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230140AbhEJHsG (ORCPT ); Mon, 10 May 2021 03:48:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58038 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230045AbhEJHsG (ORCPT ); Mon, 10 May 2021 03:48:06 -0400 Received: from mail-pg1-x532.google.com (mail-pg1-x532.google.com [IPv6:2607:f8b0:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C046C061573; Mon, 10 May 2021 00:47:02 -0700 (PDT) Received: by mail-pg1-x532.google.com with SMTP id s22so12683780pgk.6; Mon, 10 May 2021 00:47:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=glCsIRw/Boons0Drf4KT3lVP96p3GKEkMeEC68Os5U4=; b=JsUTKXdE/g3skwdL7LnCl6EiqpJKtNKwaFPoh4b/D4pBElPi3flYVX2Aa1IPDbsAgr xRr2cu1NxyhgsVdbwYZXLLhPgqqTeVIxR76kfTiDVbKPwrA5TwBAVo+BucGkjLvCXRLp uG00XoR4f4Wn2Cu0WFVWjt0vhnDVs/DVqZMbBZVzR9ZPdMOEGjCGhT22KQmJrwOaqBEj orjPAxcD+fb0osn9Kg18ioZNfgGf5yVlb+OLa/gOtbqYVK8pduU9AsvBXLrFHPIzSMYm Ho55/2iGpmz57BGnJ9FMH4fjsT8Rbz8JAm3U/Rq92iuXM58rD5CEESqcSxt4BSIbAbl7 MRTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=glCsIRw/Boons0Drf4KT3lVP96p3GKEkMeEC68Os5U4=; b=IsqP5yh6Pfe1nTKbfQmAjzTycm31nU1bt19mwWxVk767KeAt+1qMnpFbyLcyD23CCK B1hKswnxH1pskViCI8Dyfo7+J66HTKxWUB1WANaPHg6rEbZ1hfBaEgiG7YTiL4krqegp yV1on7a9t8mmxeZvcxbUNaQvLgSmih9oa9vRVtSXQ0LJD+f8A7xSEegcFXRPxnQOixV7 rWJHJUH/X/wz0fkBo4krCv8Y7UlIanDzFLR9oDS+UI9aJEe6KJ8GPH4IJ9hEPW5EitCp AgiRVBasO7NlwHN+selyKhRzCXc59T8VdB9Tv7lkKumpVzyNHK3eFY75F2bqhDshtkvN pAiw== X-Gm-Message-State: AOAM533M/Z/3XuqxzomdoekNNUG4dLBNoiLD36zq4qyVpoVh0tpW/SS1 jQlEfoFnV2co7twWiLDqmzQ= X-Google-Smtp-Source: ABdhPJwXkEq9UHxzOZKAJccYp3cqzTrBUDw/iLvqAcsS6fSYPwdXlBaPQwoOKFtRiRCOum9O+38NvQ== X-Received: by 2002:a05:6a00:c3:b029:28e:d284:c39f with SMTP id e3-20020a056a0000c3b029028ed284c39fmr24021937pfj.4.1620632821556; Mon, 10 May 2021 00:47:01 -0700 (PDT) Received: from [10.6.3.44] ([89.187.161.160]) by smtp.gmail.com with ESMTPSA id h10sm10397932pfk.210.2021.05.10.00.46.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 10 May 2021 00:47:01 -0700 (PDT) Subject: Re: [PATCH] md: don't account io stat for split bio To: Christoph Hellwig Cc: song@kernel.org, linux-raid@vger.kernel.org, linux-block@vger.kernel.org, pawel.wiejacha@rtbhouse.com, Artur Paszkiewicz References: <20210508034815.123565-1-jgq516@gmail.com> From: Guoqing Jiang Message-ID: <14a350ee-1ec9-6a15-dd76-fb01d8dd2235@gmail.com> Date: Mon, 10 May 2021 15:46:47 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 5/10/21 2:00 PM, Christoph Hellwig wrote: > On Sat, May 08, 2021 at 11:48:15AM +0800, Guoqing Jiang wrote: >> It looks like stack overflow happened for split bio, to fix this, >> let's keep split bio untouched in md_submit_bio. >> >> As a side effect, we need to export bio_chain_endio. > Err, no. The right answer is to not change ->bi_end_io of bios that > you do not own instead of using a horrible hack to skip accounting for > bios that have no more or less reason to be accounted than others bios. Thanks for the reply. I suppose that md needs to revert current implementation of accounting io stats, then re-implement it. Song and Artur, what are your opinion? Thanks, Guoqing