Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751314AbWESJfO (ORCPT ); Fri, 19 May 2006 05:35:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751323AbWESJfO (ORCPT ); Fri, 19 May 2006 05:35:14 -0400 Received: from linux01.gwdg.de ([134.76.13.21]:28860 "EHLO linux01.gwdg.de") by vger.kernel.org with ESMTP id S1751314AbWESJfN (ORCPT ); Fri, 19 May 2006 05:35:13 -0400 Date: Fri, 19 May 2006 11:34:28 +0200 (MEST) From: Jan Engelhardt To: linux-xfs@oss.sgi.com cc: Linux Kernel Mailing List Subject: XFS write speed drop Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 888 Lines: 24 Hello, I have noticed that after an upgrade from 2.6.16-rcX -> 2.6.17-rc4, writes to one (hdc) xfs filesystem have become significantly slower (factor 6 to 8), like if -o sync (or funky journal options on ext3) was on. Also, reads would stall until writes have completed. I would only expect such behavior when /proc/sys/vm/dirty_* are set to high values (like 95%, like I do on a notebook). hda remained fast. It eventually turned out that it are the log barriers; hda does not support barriers and XFS gave a nice kernel message hint that pointed me to try out a mount flag. -o nobarrier makes it fast again. Jan Engelhardt -- - 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/