From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 5 Feb 2001 13:47:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 5 Feb 2001 13:47:28 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:11274 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id ; Mon, 5 Feb 2001 13:47:18 -0500 Date: Mon, 5 Feb 2001 19:46:59 +0100 From: Jens Axboe To: Oliver Feiler Cc: linux-kernel@vger.kernel.org Subject: Re: Very high system load writing data to SCSI DVD-RAM Message-ID: <20010205194659.U5285@suse.de> In-Reply-To: <20010205193216.A198@lionking.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20010205193216.A198@lionking.org>; from kiza@lionking.org on Mon, Feb 05, 2001 at 07:32:16PM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 05 2001, Oliver Feiler wrote: > Hello, > > I have the following problem with a DVD-RAM drive. The drive is a > Panasonic LF-D101 connected to a Tekram DC395U SCSI controller. Kernel is > 2.2.18 with the patch for the Tekram controller > (http://www.garloff.de/kurt/linux/dc395/). > > When I write huge amounts of data to a DVD-RAM the system load is > getting very high, like 10 or even above and the system temporarily freezes > for a short time every minute or so while writing data to the drive. The DVD > drive writes data with 1.35 MB/sec on the discs so there is not really much This is an old problem, and not related to the dvd-ram itself. If you dirty lots of data and the target device is slow, kswapd/bdflush will go crazy trying to free up memory. It should behave better on 2.4.1, where we impose a global limit on locked buffers. Try and run a vmstat 1 while doing the copy, and send that along. > data going over the SCSI controller. Reading data from DVD-RAMs is done with > 2.7 MB/s (2x) by the drive and does not cause any problems at all. Reading is much easier to control. > There is a 4x Teac burner connected to the SCSI controller as well. > Burning CDs does not raise the system load or cause any other problems. Burning CDs is very different and does not put pressure on the mm. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/