From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757231Ab1GKNFY (ORCPT ); Mon, 11 Jul 2011 09:05:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7480 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753194Ab1GKNFX (ORCPT ); Mon, 11 Jul 2011 09:05:23 -0400 Date: Mon, 11 Jul 2011 09:05:20 -0400 From: Vivek Goyal To: Shaohua Li Cc: lkml , Jens Axboe Subject: Re: [PATCH 0/3]CFQ: add think time check for service tree and group Message-ID: <20110711130520.GA30674@redhat.com> References: <1309757789.15392.236.camel@sli10-conroe> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 11, 2011 at 01:44:05PM +0800, 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. Yep, please resend. That would be easier. Thanks Vivek