Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752556AbZITWEE (ORCPT ); Sun, 20 Sep 2009 18:04:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751425AbZITWED (ORCPT ); Sun, 20 Sep 2009 18:04:03 -0400 Received: from cantor2.suse.de ([195.135.220.15]:53139 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751277AbZITWED (ORCPT ); Sun, 20 Sep 2009 18:04:03 -0400 Date: Mon, 21 Sep 2009 00:04:05 +0200 From: Jan Kara To: Jiri Kosina Cc: Ulrich Lukas , Linux Kernel Mailing List , Jan Kara Subject: Re: Poor desktop responsiveness with background I/O-operations Message-ID: <20090920220405.GA395@duck.suse.cz> References: <4AB59CBB.8090907@datenparkplatz.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1346 Lines: 37 On Sun 20-09-09 22:22:20, Jiri Kosina wrote: > On Sun, 20 Sep 2009, Ulrich Lukas wrote: > > > Test case: > > - 64-bit dual-core PC, SATA harddrive, plenty of free RAM > > - vanilla Linux 2.6.31, Kubuntu 9.10 packages, all software 64-bit > > > > > > How to reproduce: > > - start KDE/GNOME-session > > - open a terminal window and do as a non-root user: > > dd if=/dev/zero of=/home/john-doe/testfile > > (or dd if=/home/john-doe/big-testfile of=/dev/null) > > > > - a real use scenario would be a daily disk-backup or the > > simple extraction of a tarball containing slightly bigger files > > > > > > Observation: > > - The system becomes _really_ slow as described above; unusable for > > any multimedia tasks. > > I guess that switching from CFQ to deadline I/O scheduler improves the > situation, right? For example on my desktop, switching to deadline slightly improves the situation but the machine is still mostly unusable while dd is running... I'll try to debug it some more to see whether it can be somehow helped. Honza -- Jan Kara SUSE Labs, CR -- 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/