Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965286AbXAKBLW (ORCPT ); Wed, 10 Jan 2007 20:11:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965289AbXAKBLW (ORCPT ); Wed, 10 Jan 2007 20:11:22 -0500 Received: from omx2-ext.sgi.com ([192.48.171.19]:38876 "EHLO omx2.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S965286AbXAKBLV (ORCPT ); Wed, 10 Jan 2007 20:11:21 -0500 Date: Thu, 11 Jan 2007 12:11:05 +1100 From: David Chinner To: David Chinner Cc: Christoph Lameter , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [REGRESSION] 2.6.19/2.6.20-rc3 buffered write slowdown Message-ID: <20070111011105.GV33919298@melbourne.sgi.com> References: <20070110223731.GC44411608@melbourne.sgi.com> <20070110230855.GF44411608@melbourne.sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070110230855.GF44411608@melbourne.sgi.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 909 Lines: 27 On Thu, Jan 11, 2007 at 10:08:55AM +1100, David Chinner wrote: > On Wed, Jan 10, 2007 at 03:04:15PM -0800, Christoph Lameter wrote: > > On Thu, 11 Jan 2007, David Chinner wrote: > > > > > The performance and smoothness is fully restored on 2.6.20-rc3 > > > by setting dirty_ratio down to 10 (from the default 40), so > > > something in the VM is not working as well as it used to.... > > > > dirty_background_ratio is left as is at 10? > > Yes. FWIW, setting dirty_ratio to 20 instead of 10 fixes the most of the erraticness of the writeback and most of the performance as well. Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group - 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/