From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 24 Apr 2001 10:01:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 24 Apr 2001 10:01:39 -0400 Received: from ford.balliol.ox.ac.uk ([163.1.209.24]:5248 "EHLO ford.balliol.ox.ac.uk") by vger.kernel.org with ESMTP id ; Tue, 24 Apr 2001 10:01:20 -0400 Date: Tue, 24 Apr 2001 15:00:21 +0100 From: Thomas Ford To: linux-kernel@vger.kernel.org Subject: PIO disk writes using 100% system time and performing poorly with VIA vt82c686b on kernels 2.2 & 2.4 Message-ID: <20010424150020.A712@ford.balliol.ox.ac.uk> Reply-To: thomas.ford@balliol.ox.ac.uk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Heavy disc writes (eg. unzipping linux kernel source) cause the system processor usage (as reported by top/xosview) to jump to 100%, making the X mouse/audio freeze etc. Such problems occur with the drives connected to VIA vt82c686b south bridge: the same drives on a mvp3 show no such problems. The behaviour is the same on kernels 2.2.17 & 2.4.3 (both hand compiled & RedHat's 2.4.2-2 & 2.2.17-14 in case I was doing something wrong). The problem is easily demonstrated by hdparm -t. The CPU use jumps to system 100% as above and all my drives report ~1.9 MB/sec in PIO mode which is far lower than PIO on the mvp3 (~10MB/s). DMA mode appears to work fine but I am not using it due to publicised potential problems. Regards, Tom Ford