From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751966Ab1GWIHl (ORCPT ); Sat, 23 Jul 2011 04:07:41 -0400 Received: from mga03.intel.com ([143.182.124.21]:33872 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751471Ab1GWIHe (ORCPT ); Sat, 23 Jul 2011 04:07:34 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,252,1309762800"; d="scan'208";a="30600769" Date: Sat, 23 Jul 2011 16:07:21 +0800 From: Wu Fengguang To: Vivek Goyal Cc: "linux-fsdevel@vger.kernel.org" , Jan Kara , Dave Chinner , Christoph Hellwig , Andrew Morton , "Li, Shaohua" , Peter Zijlstra , LKML Subject: Re: [PATCH 3/9] writeback: bdi write bandwidth estimation Message-ID: <20110723080721.GC31975@localhost> References: <20110629145245.835998321@intel.com> <20110629145553.906668553@intel.com> <20110701192915.GE28563@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110701192915.GE28563@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jul 02, 2011 at 03:29:15AM +0800, Vivek Goyal wrote: > On Wed, Jun 29, 2011 at 10:52:48PM +0800, Wu Fengguang wrote: > > The estimation value will start from 100MB/s and adapt to the real > > bandwidth in seconds. > > > > It tries to update the bandwidth only when disk is fully utilized. > > Any inactive period of more than one second will be skipped. > > Is this piece of code being tested in your graphs? Are there any > inactive periods which get filtered out in your workload? I am > assuming in a continuous dd, we will not have periods of inactivity > 1 second long. There are no inactive periods in the dd tests. However I did try "watch cat /debug/bdi/8:0/stats" while starting some write workloads in background. When the write stops, the bandwidth does stop updating. Thanks, Fengguang