From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751301AbWCaJsx (ORCPT ); Fri, 31 Mar 2006 04:48:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751303AbWCaJsx (ORCPT ); Fri, 31 Mar 2006 04:48:53 -0500 Received: from unthought.net ([212.97.129.88]:4876 "EHLO unthought.net") by vger.kernel.org with ESMTP id S1751301AbWCaJsx (ORCPT ); Fri, 31 Mar 2006 04:48:53 -0500 Date: Fri, 31 Mar 2006 11:48:51 +0200 From: Jakob Oestergaard To: linux-kernel@vger.kernel.org Subject: NFS client (10x) performance regression 2.6.14.7 -> 2.6.15 Message-ID: <20060331094850.GF9811@unthought.net> Mail-Followup-To: Jakob Oestergaard , linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi guys, I just found out... Installed 2.6.16.1 (32-bit) on a spanking new dual opteron 275 (dual-core) machine, and saw that my link jobs were taking ages. I narrowed it down a bit - these are the kernels I have tested: 2.6.13.5: Good 2.6.14.7: Good 2.6.15: Poor 2.6.15.7: Poor 2.6.16.1: Poor Sequential NFS I/O is good on all kernels. Only "ld" shows the problem. On 2.6.14.7, I can run a large link job creating a 60 MB executable in 15.6 seconds wall-clock time. On 2.6.15, the same link job takes 2 minutes 28 seconds. This is almost 10 *times* longer. Testing with tiobench, I can see no notable difference between the kernels (!) It seems that this is very specific to ld. I am using GNU ld version 2.15. The NFS client mounts the working directory using NFS v3 over UDP with default (32k) rsize/wsize. Since this machine is not in production yet, I can experiment with kernel patches on it - I would like to try and narrow this down even further - any suggestions as to which patches to exclude/include will be greatly appreciated. Note; I did double-check all the common problems (ethernet problems, mount options, ...). -- / jakob