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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 0EE9CC433DB for ; Wed, 13 Jan 2021 06:00:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9D2323102 for ; Wed, 13 Jan 2021 06:00:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725910AbhAMGAJ (ORCPT ); Wed, 13 Jan 2021 01:00:09 -0500 Received: from mga12.intel.com ([192.55.52.136]:22208 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725747AbhAMGAJ (ORCPT ); Wed, 13 Jan 2021 01:00:09 -0500 IronPort-SDR: WFA/We/XhjR2iICuhamEyirbxyrHmc9lZgfPUnuPPGM2o1y7ico9wNYkg/ypLurQF6B5EL+DHD YuCf8zFc3chQ== X-IronPort-AV: E=McAfee;i="6000,8403,9862"; a="157336076" X-IronPort-AV: E=Sophos;i="5.79,343,1602572400"; d="scan'208";a="157336076" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2021 21:58:23 -0800 IronPort-SDR: 00jdNjGlZmk0NfEWCPA7W7mk3N5yP1gamiM4n7U/LWJqVLnRU0n2p0jiRDIUHha+IhNN08wyEZ TYGNaxV9fyuw== X-IronPort-AV: E=Sophos;i="5.79,343,1602572400"; d="scan'208";a="381717481" Received: from xingzhen-mobl.ccr.corp.intel.com (HELO [10.255.30.69]) ([10.255.30.69]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2021 21:58:20 -0800 Subject: Re: [LKP] Re: [btrfs] e076ab2a2c: fio.write_iops -18.3% regression To: dsterba@suse.cz, kernel test robot , Josef Bacik , David Sterba , =?UTF-8?Q?Ren=c3=a9_Rebe?= , LKML , lkp@lists.01.org, lkp@intel.com, ying.huang@intel.com, feng.tang@intel.com, linux-btrfs@vger.kernel.org References: <20210112153614.GA2015@xsang-OptiPlex-9020> <20210112154529.GT6430@twin.jikos.cz> From: Xing Zhengjun Message-ID: <979aee28-c603-a187-e03f-29957c7b94d6@linux.intel.com> Date: Wed, 13 Jan 2021 13:58:18 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: <20210112154529.GT6430@twin.jikos.cz> 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-kernel@vger.kernel.org On 1/12/2021 11:45 PM, David Sterba wrote: > On Tue, Jan 12, 2021 at 11:36:14PM +0800, kernel test robot wrote: >> Greeting, >> >> FYI, we noticed a -18.3% regression of fio.write_iops due to commit: >> >> >> commit: e076ab2a2ca70a0270232067cd49f76cd92efe64 ("btrfs: shrink delalloc pages instead of full inodes") >> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master >> >> >> in testcase: fio-basic >> on test machine: 192 threads Intel(R) Xeon(R) CPU @ 2.20GHz with 192G memory >> with following parameters: >> >> disk: 1SSD >> fs: btrfs >> runtime: 300s >> nr_task: 8 >> rw: randwrite >> bs: 4k >> ioengine: sync >> test_size: 256g > Though I do a similar test (emulating bit torrent workload), it's a bit > extreme as it's 4k synchronous on a huge file. It always takes a lot of > time but could point out some concurrency issues namely on faster > devices. There are 8 threads possibly competing for the same inode lock > or other locks related to it. > > The mentioned commit fixed another perf regression on a much more common > workload (untgrring files), so at this point drop in this fio workload > is inevitable. Do you have a plan to fix it? Thanks. > _______________________________________________ > LKP mailing list -- lkp@lists.01.org > To unsubscribe send an email to lkp-leave@lists.01.org -- Zhengjun Xing