Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 8 Apr 2002 11:07:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 8 Apr 2002 11:07:39 -0400 Received: from gw.wmich.edu ([141.218.1.100]:62143 "EHLO gw.wmich.edu") by vger.kernel.org with ESMTP id ; Mon, 8 Apr 2002 11:07:38 -0400 Subject: Re: PROMBLEM: CD burning at 16x uses excessive CPU, although DMA is enabled From: Ed Sweetman To: Bill Davidsen Cc: Anssi Saari , linux-kernel@vger.kernel.org In-Reply-To: Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Ximian Evolution 1.0.3 Date: 08 Apr 2002 11:06:28 -0400 Message-Id: <1018278394.570.143.camel@psuedomode> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I'm not completely sure about burning audio, but linux doesn't read audio cds using DMA. It just wont on ide devices. You can use a patch that allows this from andrew morton. I dont write many audio cds so I've never tested it's effect on writing a cd, only reading. I imagine it's not safe to use dma on raw/audio cds. but go check it out anyways. On Mon, 2002-04-08 at 10:54, Bill Davidsen wrote: > On Mon, 8 Apr 2002, Anssi Saari wrote: > > > [1.] One line summary of the problem: > > CD burning at 16x uses excessive CPU, although DMA is enabled > > That's a hint things are not working as you expect... > > > [2.] Full description of the problem/report: > > My system seems to use a lot of CPU time when writing CDs at 16x. The > > system is unable to feed the burning software's buffer fast enough when > > burning software (cdrecord 1.11a20, cdrdao 1.1.5) is run as normal user. > > If run as root, system is almost unresponsive during the burn. > > With all the information you provided, you have totally not quatified > how much CPU you find "excessive." I would not be surprised to see 10-15% > of the CPU, virtually all in system time, as a normal burn of an ISO > image. If the time is in user mode with other image types, it may well be > that you are doing something which actually requires a lot of CPU (byte > swapping or some such). > > Going from a disk to a CD using DMA on both should not take much > *system* CPU, even if these are ATAPI (assuming they are not on the same > cable). > > -- > bill davidsen > CTO, TMR Associates, Inc > Doing interesting things with little computers since 1979. > > - > 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/ - 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/