From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750726AbWGORqK (ORCPT ); Sat, 15 Jul 2006 13:46:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750736AbWGORqK (ORCPT ); Sat, 15 Jul 2006 13:46:10 -0400 Received: from mail.gmx.net ([213.165.64.21]:6079 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S1750726AbWGORqJ (ORCPT ); Sat, 15 Jul 2006 13:46:09 -0400 X-Authenticated: #5082238 Date: Sat, 15 Jul 2006 19:45:57 +0200 From: Carsten Otto To: linux-kernel@vger.kernel.org Subject: Very poor IO performance (high CPU load), libata Message-ID: <20060715174555.GA27640@server.c-otto.de> Reply-To: c-otto@gmx.de Mail-Followup-To: linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="9jxsPFA5p3P2qPhR" Content-Disposition: inline X-GnuGP-Key: http://c-otto.de/pubkey.asc User-Agent: Mutt/1.5.11+cvs20060403 X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --9jxsPFA5p3P2qPhR Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hello (again)! System specs below. My system sometimes[1] crashes in the sense that every HDD access is slow as hell and most of both CPUs' power is used for IO waiting. Then "top" shows more than 80% "wa" and the corresponding counter in /proc/stat increases a lot. When plotting these values with rrdtool I see up to 5% IO wait with normal behaviour and peaks with up to 40% under heavy load. In the problem case the IO wait never drops below 40% no matter how light the HDD load is. Logging in into the system via SSH then takes more than two minutes and other tasks are equally slow. Disabling AHCI/ACPI/SMP in the kernel did not help. I also tried several kernel versions including 2.6.16 to 2.6.18 (rc, mm). /proc/interrupts shows a lot of interrupts for my network cards, but disabling the network does not solve the problem. A reboot usually solves the problem for some time. There might be a problem with my hardware (in a not yet determined device) causing this problem. But as long as I do not know what is wrong I still see the chance of a software error in the kernel. System specs: - Mainboard with Intel 945p and iCH7R (Foxconn 945P7AA-8EKRS2) - Intel Pentium D 805 (Dual Core, 2.66 GHz, 1 MB cache each) - 4x Maxtor MaXLine III (300GB, 16MB Cache, SATA2) [1] Sometimes: More than daily, at the moment I am lucky and noticed no problem for hours. Thanks a lot, --=20 Carsten Otto c-otto@gmx.de www.c-otto.de --9jxsPFA5p3P2qPhR Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (GNU/Linux) iD8DBQFEuSnTjUF4jpCSQBQRAoi5AKChMpXiLfXY04Qf26LTDfTTuC8kYwCcDpaF ZS4fK2/IygYOxMLzNzgc4J8= =m8f9 -----END PGP SIGNATURE----- --9jxsPFA5p3P2qPhR--