Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266870AbUIAP3W (ORCPT ); Wed, 1 Sep 2004 11:29:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266890AbUIAP3W (ORCPT ); Wed, 1 Sep 2004 11:29:22 -0400 Received: from upco.es ([130.206.70.227]:13035 "EHLO mail1.upco.es") by vger.kernel.org with ESMTP id S266870AbUIAP2U (ORCPT ); Wed, 1 Sep 2004 11:28:20 -0400 Date: Wed, 1 Sep 2004 17:28:17 +0200 From: Romano Giannetti To: Linux Kernel Mailing List Subject: Re: Driver retries disk errors. Message-ID: <20040901152817.GA4375@pern.dea.icai.upco.es> Mail-Followup-To: Romano Giannetti , Linux Kernel Mailing List References: <20040830163931.GA4295@bitwizard.nl> <1093952715.32684.12.camel@localhost.localdomain> <20040831135403.GB2854@bitwizard.nl> <1093961570.597.2.camel@localhost.localdomain> <20040831155653.GD17261@harddisk-recovery.com> <1093965233.599.8.camel@localhost.localdomain> <20040831170016.GF17261@harddisk-recovery.com> <1093968767.597.14.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1093968767.597.14.camel@localhost.localdomain> User-Agent: Mutt/1.5.5.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1623 Lines: 36 On Tue, Aug 31, 2004 at 05:12:50PM +0100, Alan Cox wrote: > > > (1) Imagine an application doing a linear read on a file with an 8 > > block read ahead and the last block being bad. The kernel will try to > > read that bad block 16 times, but because the IDE driver also has 8 > > retries, the kernel will try to read that bad block *64* times. It > > usually takes an IDE drive about 2 seconds to figure out a block is > > bad, so the application gets stuck for 2 minutes in that single bad > > block. > > Right now I know of no way to tell which is readahead for a failed > command or of telling the block layer to forget them. Fix this at the > block layer and IDE can abort the readahead sequence happily enough > because IDE is too dumb to have issued further commands to the drive at > this point. Just a question from a kernel-almost-illiterate. Could this explain the behavior of my laptop yesterday, reading a damaged DVD? I had to wait almost one full minute of retry until being able to kill xine... If maintaining the retries, it could be nice to allow at least kill -9 between them. I do not know if that's foolish and/or impossible, so please do not bash too hard... Have a nice day, Romano -- Romano Giannetti - Univ. Pontificia Comillas (Madrid, Spain) Electronic Engineer - phone +34 915 422 800 ext 2416 fax +34 915 596 569 - 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/