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=-7.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,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 67666C433DF for ; Thu, 6 Aug 2020 17:36:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5A8E206B2 for ; Thu, 6 Aug 2020 17:36:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="wi4dRPNx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727979AbgHFRgO (ORCPT ); Thu, 6 Aug 2020 13:36:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730412AbgHFRfY (ORCPT ); Thu, 6 Aug 2020 13:35:24 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3559DC008698 for ; Thu, 6 Aug 2020 08:16:37 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id j21so8168615pgi.9 for ; Thu, 06 Aug 2020 08:16:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=lkmeDFCb+vAIp5A4XwAMAJW588/NOgnU33kU5Ds2q8U=; b=wi4dRPNxYEFgOvGpsjjRxtDn2I9IamqHuFJzrb9/BuBRChg/enUxUB6jKiVJyf6FSn OEQMb2RXR2Ht+C6Ju/CpXw+3C8IXjLBhGdgnDRc+0mD42UF2fgmfGBI+NDEQDfVS+FPg 8Yte0Alz1AaaMd1lh6L2ptLcnhrBzWalCQR42JDJeAyQD1H9NJDT0b18q5zQqirTk5sw MQTa65RVxamAwTEOlvLR1qATaDfFMPrdnpkmrZ75l2JmkJ2Zy9MPxE1hZyGlCwG5lUWc dMIBO4mmLkijKg2CX5kvhARvLNuj4R+a6FF2AhYbKN6g85KDBnPw2HmOoO1VsmzJJPBe 6lpA== 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-language :content-transfer-encoding; bh=lkmeDFCb+vAIp5A4XwAMAJW588/NOgnU33kU5Ds2q8U=; b=oPzGrZc8I2FvFWNUw3Vpv8Qn+G8hHlMu7wIJudj2mkscblt7Nn50GJaBn6w+/meHGn +1kSHbFzEpUr1YB3uTYqceRAfOd9E8qnLqKdnPjBIY8VTG2HDDaq/gQ++gkXYLd2R0co 71v519fZ7rojepVX8cnEim4E4evE4jbIJ6rDqkP7VRV/V9WfYU3VG+JNnB1O9utiMQuh LCgM5qBIp5f0mheutLK++h1p4Nr7ynxbI0Ul4BzYQOKBx0PZhRsJPMHGo6JgQiNmus6R XGJoNQH26NPJw+qEPX6cdVUWlfPIMQePNXw67kiBdv9zWzIAUXpy6uUsCgbAc32igEBy +VKg== X-Gm-Message-State: AOAM532/cOIlN0NasApgR8X8M30ceGVWveaYquxtccVRD3hj/G4aep4i 2YMKqCb3BtHwH1FmdjMsjPJBrwdiP0Q= X-Google-Smtp-Source: ABdhPJw12jZ3DwVtFWJem2DsB0Vuvxs5W1jsJdh1xkbPJ6eXu/HRB7XOi58ujieN7nBfCOicKddtyw== X-Received: by 2002:a63:fd41:: with SMTP id m1mr1061769pgj.12.1596726996234; Thu, 06 Aug 2020 08:16:36 -0700 (PDT) Received: from [192.168.1.58] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id b15sm7241610pjo.48.2020.08.06.08.16.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 06 Aug 2020 08:16:35 -0700 (PDT) Subject: Re: [PATCH] blkcg: add plugging support for punt bio To: Xianting Tian , tj@kernel.org Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <1596722082-31817-1-git-send-email-xianting_tian@126.com> From: Jens Axboe Message-ID: <8f84e1fe-9fa5-b7e7-1f2f-b0c4a40614e2@kernel.dk> Date: Thu, 6 Aug 2020 09:16:34 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <1596722082-31817-1-git-send-email-xianting_tian@126.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/6/20 7:54 AM, Xianting Tian wrote: > Try to merge continuous bio to current task's plug fisrt. The patch looks fine to me, but I'd really like to see a bit more changelog here. The commit message should explain why the change is made, rather it's a very brief explanation of what it does. If the bio list is contiguous, then we do the plugging to improve merging at the lower level. You probably ran into a case where you saw sub-optimal merging? And now the performance is better with the patch? How much? -- Jens Axboe