From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759798Ab2BJS0H (ORCPT ); Fri, 10 Feb 2012 13:26:07 -0500 Received: from mail-qw0-f46.google.com ([209.85.216.46]:55793 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759776Ab2BJS0E (ORCPT ); Fri, 10 Feb 2012 13:26:04 -0500 Message-ID: <4F356139.9000609@pobox.com> Date: Fri, 10 Feb 2012 13:26:01 -0500 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:9.0) Gecko/20111222 Thunderbird/9.0 MIME-Version: 1.0 To: qiang.liu@freescale.com CC: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH V2] fsl-sata: I/O load balancing References: <1327025958-10605-1-git-send-email-qiang.liu@freescale.com> In-Reply-To: <1327025958-10605-1-git-send-email-qiang.liu@freescale.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/19/2012 09:19 PM, qiang.liu@freescale.com wrote: > From: Qiang Liu > > Reduce interrupt signals through reset Interrupt Coalescing Control Reg. > Provide dynamic method to adjust interrupt signals and timer ticks by sysfs. > It is a tradeoff for different applications. > > Signed-off-by: Qiang Liu > --- > > change for V2 > support dynamic config interrupt coalescing register by /sysfs > test random small file with iometer > Description: > 1. fsl-sata interrupt will be raised 130 thousand times when write 8G file > (dd if=/dev/zero of=/dev/sda2 bs=128K count=65536); > 2. most of interrupts raised because of only 1-4 commands completed; > 3. only 30 thousand times will be raised after set max interrupt threshold, > more interrupts are coalesced as the description of ICC; > > Test methods and results: > 1. test sequential large file performance, > [root@p2020ds root]# echo 31 524287> \ > /sys/devices/soc.0/ffe18000.sata/intr_coalescing > [root@p2020ds root]# dd if=/dev/zero of=/dev/sda2 bs=128K count=65536& > [root@p2020ds root]# top > > CPU % | dd | flush-8:0 | softirq > --------------------------------------- > before | 20-22 | 17-19 | 7 > --------------------------------------- > after | 18-21 | 15-16 | 5 > --------------------------------------- > 2. test random small file with iometer, > iometer paramters: > 4 I/Os burst length, 1MB transfer request size, 100% write, 2MB file size > as default configuration of interrupt coalescing register, 1 interrupts and > no timeout config, total write performance is 119MB per second, > after config with the maximum value, write performance is 110MB per second. > > After compare the test results, a configuable interrupt coalescing should be > better when cope with flexible context. > > drivers/ata/sata_fsl.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++-- > 1 files changed, 107 insertions(+), 4 deletions(-) Doesn't seem to apply to upstream, or another less recent -rc... Jeff