From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com ([134.134.136.20]:43491 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752520AbeFFBno (ORCPT ); Tue, 5 Jun 2018 21:43:44 -0400 Date: Wed, 6 Jun 2018 09:40:28 +0800 From: Ye Xiaolong Subject: Re: [lkp-robot] [xfs] b027d4c97b: fio.latency_2ms% +7.1% regression Message-ID: <20180606014028.GQ16472@yexl-desktop> References: <20180605071657.GP16472@yexl-desktop> <20180605223813.GI10363@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180605223813.GI10363@dastard> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Dave Chinner Cc: Dave Chinner , "Darrick J. Wong" , Christoph Hellwig , Carlos Maiolino , LKML , linux-xfs@vger.kernel.org, lkp@01.org On 06/06, Dave Chinner wrote: >On Tue, Jun 05, 2018 at 03:16:57PM +0800, kernel test robot wrote: >> >> Greeting, >> >> FYI, we noticed a +7.1%% regression of fio.latency_2ms% due to commit: >> >> >> commit: b027d4c97b9675c2ad75dec94be4e46dceb3ec74 ("xfs: don't retry xfs_buf_find on XBF_TRYLOCK failure") >> https://git.kernel.org/cgit/fs/xfs/xfs-linux.git xfs-4.18-merge >.... >> 8925a3dc4771004b b027d4c97b9675c2ad75dec94b >> ---------------- -------------------------- >> %stddev %change %stddev >> \ | \ >> 46.56 ± 3% +7.1 53.61 fio.latency_2ms% >> 8.19 +0.2 8.40 fio.latency_100ms% >> 0.74 ± 3% -0.1 0.68 ± 6% fio.latency_250ms% >> 25.20 ± 6% -7.3 17.86 ± 6% fio.latency_4ms% >> 0.46 ± 9% +0.2 0.69 ± 13% fio.latency_750us% > >This is not a regression. The number of IOs in the 4ms IO latency >bin has reduced by 7%, and inumber in the 2ms IO latency bin has >increased by 7%. IOWs, there's a measurable improvement in IO >latency as a result of those patches, not a regression. Thanks for clarification. Thanks, Xiaolong > >Cheers, > >Dave. >-- >Dave Chinner >david@fromorbit.com