From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754993Ab1GKL15 (ORCPT ); Mon, 11 Jul 2011 07:27:57 -0400 Received: from mx1.fusionio.com ([66.114.96.30]:60359 "EHLO mx1.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754477Ab1GKL15 (ORCPT ); Mon, 11 Jul 2011 07:27:57 -0400 X-ASG-Debug-ID: 1310383675-03d6a510a8142d50001-xx1T2L X-Barracuda-Envelope-From: JAxboe@fusionio.com Message-ID: <4E1ADE39.6090609@fusionio.com> Date: Mon, 11 Jul 2011 13:27:53 +0200 From: Jens Axboe MIME-Version: 1.0 To: Shaohua Li CC: lkml , Vivek Goyal Subject: Re: [PATCH 0/3]CFQ: add think time check for service tree and group References: <1309757789.15392.236.camel@sli10-conroe> X-ASG-Orig-Subj: Re: [PATCH 0/3]CFQ: add think time check for service tree and group In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Barracuda-Connect: mail1.int.fusionio.com[10.101.1.21] X-Barracuda-Start-Time: 1310383675 X-Barracuda-URL: http://10.101.1.180:8000/cgi-mod/mark.cgi X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using per-user scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=9.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.2.68605 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2011-07-11 07:44, Shaohua Li wrote: > 2011/7/4 Shaohua Li : >> Hi, >> Currently when the last queue of a service tree/group is empty, CFQ >> doesn't expire the queue. This is to allow requests from the tree/group >> come soon, so tree/group doesn't miss its share. But if the think time >> is big, the assumption isn't correct. idling the queue is just wasting >> bandwidth. >> >> Originally I was hoping this can resolve Vivek's fsync issue, but it >> doesn't. The fsync issue is caused by queue idling. But since think time >> check only helps for think time above default queue idle time (8ms), >> think time check doesn't help. >> >> On the other hand, think time check is still helpful for queues with >> think time. I had test case in follow patches show throughput >> improvement without sacrifice tree/group shares. >> > Jens, > can you look at the patches? I refreshed some patches in replying > Vivek, I can resend if required. Please resend the series after a refresh like that, otherwise I tend to lose track of the various things flying around. -- Jens Axboe