Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757423AbaDWIVU (ORCPT ); Wed, 23 Apr 2014 04:21:20 -0400 Received: from mga09.intel.com ([134.134.136.24]:27321 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754124AbaDWIVR (ORCPT ); Wed, 23 Apr 2014 04:21:17 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,910,1389772800"; d="scan'208";a="517799278" Message-ID: <535777F2.1050501@intel.com> Date: Wed, 23 Apr 2014 16:21:06 +0800 From: Jet Chen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Dan Williams CC: Tejun Heo , LKML , lkp@01.org, Fengguang Wu Subject: Re: [libata/ahci] 8a4aeec8d2d: +138.4% perf-stat.dTLB-store-misses, +37.2% perf-stat.dTLB-load-misses References: <5354C8F3.3050504@intel.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/23/2014 01:11 AM, Dan Williams wrote: > On Mon, Apr 21, 2014 at 12:29 AM, Jet Chen wrote: >> HI Dan, >> >> we noticed the below changes on >> >> git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata for-next >> commit 8a4aeec8d2d6a3edeffbdfae451cdf05cbf0fefd ("libata/ahci: accommodate >> tag ordered controllers") > > Hi, was this on simulated hardware or a real AHCI controller and disk? > Testing was on a physical machine with a real AHCI controller. root@bay ~# lspci | grep AHCI 00:1f.2 SATA controller: Intel Corporation 82801IR/IO/IH (ICH9R/DO/DH) 6 port SATA Controller [AHCI mode] (rev 02) > It does appear this test noticed increased throughput: > > 203893 ~ 0% +3.7% 211474 ~ 0% TOTAL iostat.sda.wkB/s > > I wonder if ap->last_tag can be moved to a hotter cacheline, but if > throughput goes up I can imagine it throws off the cpu statistics > quite a bit. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/