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=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 DBE52C3F2D1 for ; Wed, 4 Mar 2020 08:15:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB7182166E for ; Wed, 4 Mar 2020 08:15:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728915AbgCDIPn (ORCPT ); Wed, 4 Mar 2020 03:15:43 -0500 Received: from mga04.intel.com ([192.55.52.120]:16101 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728885AbgCDIPm (ORCPT ); Wed, 4 Mar 2020 03:15:42 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Mar 2020 00:15:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,513,1574150400"; d="scan'208";a="352036316" Received: from xingzhen-mobl1.ccr.corp.intel.com (HELO [10.255.29.85]) ([10.255.29.85]) by fmsmga001.fm.intel.com with ESMTP; 04 Mar 2020 00:15:39 -0800 Subject: Re: [LKP] Re: [ext4] b1b4705d54: filebench.sum_bytes_mb/s -20.2% regression To: Rong Chen , Jan Kara , "Theodore Y. Ts'o" , Matthew Bobrowski Cc: Ritesh Harjani , LKML , Linus Torvalds , lkp@lists.01.org References: <20191224005915.GW2760@shao2-debian> <20200107134106.GD25547@quack2.suse.cz> <20200107165708.GA3619@mit.edu> <20200107172824.GK25547@quack2.suse.cz> From: Xing Zhengjun Message-ID: <7ec6b078-7b09-fb87-8ad2-a328e96c5bf9@linux.intel.com> Date: Wed, 4 Mar 2020 16:15:38 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Matthew, We test it in v5.6-rc4, the issue still exist, do you have time to take a look at this? Thanks. On 1/8/2020 10:31 AM, Rong Chen wrote: > > > On 1/8/20 1:28 AM, Jan Kara wrote: >> On Tue 07-01-20 11:57:08, Theodore Y. Ts'o wrote: >>> On Tue, Jan 07, 2020 at 02:41:06PM +0100, Jan Kara wrote: >>>> Hello, >>>> >>>> On Tue 24-12-19 08:59:15, kernel test robot wrote: >>>>> FYI, we noticed a -20.2% regression of filebench.sum_bytes_mb/s due >>>>> to commit: >>>>> >>>>> >>>>> commit: b1b4705d54abedfd69dcdf42779c521aa1e0fbd3 ("ext4: introduce >>>>> direct I/O read using iomap infrastructure") >>>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master >>>>> >>>>> in testcase: filebench >>>>> on test machine: 8 threads Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz >>>>> with 8G memory >>>>> with following parameters: >>>>> >>>>>     disk: 1HDD >>>>>     fs: ext4 >>>>>     test: fivestreamreaddirect.f >>>>>     cpufreq_governor: performance >>>>>     ucode: 0x27 >>>> I was trying to reproduce this but I failed with my test VM. I had >>>> SATA SSD >>>> as a backing store though so maybe that's what makes a difference. >>>> Maybe >>>> the new code results in somewhat more seeks because the five threads >>>> which >>>> compete in submitting sequential IO end up being more interleaved? >>> A "-20.2% regression" should be read as a "20.2% performance >>> improvement" is zero-day kernel speak. >> Are you sure? I can see: >> >>       58.30 ±  2%     -20.2%      46.53        filebench.sum_bytes_mb/s >> >> which implies to me previously the throughput was 58 MB/s and after the >> commit it was 46 MB/s? >> >> Anyway, in my testing that commit made no difference in that benchmark >> whasoever (getting around 97 MB/s for each thread before and after the >> commit). >>                                 Honza > > We're sorry for the misunderstanding, "-20.2%" means the change of > filebench.sum_bytes_mb/s, > "regression" means the explanation of this change from LKP. > > Best Regards, > Rong Chen > _______________________________________________ > LKP mailing list -- lkp@lists.01.org > To unsubscribe send an email to lkp-leave@lists.01.org -- Zhengjun Xing