Received: by 2002:ac0:a5b6:0:0:0:0:0 with SMTP id m51-v6csp233671imm; Tue, 5 Jun 2018 18:45:42 -0700 (PDT) X-Google-Smtp-Source: ADUXVKJ1mIw2fUSixzwZd8H5rbq+nduwlTptJ9kJKklU7saBwdLyVkl4le8Lfy+ZAIlMEUhegeNl X-Received: by 2002:a63:6c49:: with SMTP id h70-v6mr898996pgc.34.1528249542673; Tue, 05 Jun 2018 18:45:42 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1528249542; cv=none; d=google.com; s=arc-20160816; b=qiXfGPisbwDig+llhbk8pH8J+oe4/cP9Xi4guxel7WU3w+5cuORXsS5iUqs12G1hb2 hSLofVJ/31WIQYg35PKEn7ZAa8+vJQ22X6N2b9rjmUNV9dVal7QbprWKnjw+DVZK9c1v 8HUuw5Ygo+Q15YCZuUWowIjQdTmYkO4HoS02faga04ROAqOzB+PfCPTLnQ0rdQVVDswj yuNqi+542lxApfBRfNQfsvYyGRuCSJf8t/0LvwljDM7Sid0rp4Udb+6bLnvLSzfZSIIb 3OMqtGjMhJYqWy52mZYA3HTTNKWAGikpsSfaDvg2k5esmaRyB7EWCJ/x8YDZkDt29l+f WCZA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-transfer-encoding:content-disposition:mime-version :references:message-id:subject:cc:to:from:date :arc-authentication-results; bh=Wg1lHZ3NUvVzVs+f9YYpRqW02aN/9pzQMO249fOx9LI=; b=Q+2eFQ2q9zgIdzkylcuV6+AetehKcfqhoEOy1U4C+JKq+eRwaB26JG5t/Pia13cPIo +69HV1LfBMrRzvBMcMPl1GovNKy8w+ae++yFDwFCR5G9RfzjRX53GdwzUOBqzpZEtHFl U9W+m/vgX1J7d5lOe1qfsMweAtLUqZRpAGaEkcggsGMGYEb1vx8n++8gE+byCUjeoiy+ chGR+ecgPs5hrqVPyBinK+NjxIgmGsWekcnMgHGHRdhUYpiNEzL3RQ9rNdGznFzVzXTK ost2pHn8EaoNnGz0cWISe4cUUtxD8WtyBUr7/R8J16h6zfNhr5RpoWpOlyqJ5cQd6SYB lCFQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id t194-v6si1629533pgc.327.2018.06.05.18.45.28; Tue, 05 Jun 2018 18:45:42 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932072AbeFFBnq (ORCPT + 99 others); Tue, 5 Jun 2018 21:43:46 -0400 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 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Jun 2018 18:43:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,481,1520924400"; d="scan'208";a="56867206" Received: from yexl-desktop.sh.intel.com (HELO localhost) ([10.239.159.124]) by orsmga003.jf.intel.com with ESMTP; 05 Jun 2018 18:43:42 -0700 Date: Wed, 6 Jun 2018 09:40:28 +0800 From: Ye Xiaolong To: Dave Chinner Cc: Dave Chinner , "Darrick J. Wong" , Christoph Hellwig , Carlos Maiolino , LKML , linux-xfs@vger.kernel.org, lkp@01.org 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> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.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