Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751341AbWJMQ36 (ORCPT ); Fri, 13 Oct 2006 12:29:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751742AbWJMQ35 (ORCPT ); Fri, 13 Oct 2006 12:29:57 -0400 Received: from smtp.osdl.org ([65.172.181.4]:24037 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751341AbWJMQ34 (ORCPT ); Fri, 13 Oct 2006 12:29:56 -0400 Date: Fri, 13 Oct 2006 09:29:41 -0700 From: Andrew Morton To: Helge Hafting Cc: linux-kernel@vger.kernel.org, linux-usb-devel@lists.sourceforge.net Subject: Re: 2.6.19-rc1-mm1 - locks when using "dd bs=1M" from card reader Message-Id: <20061013092941.30500a15.akpm@osdl.org> In-Reply-To: <452F906F.8020302@aitel.hist.no> References: <20061010000928.9d2d519a.akpm@osdl.org> <452E327C.9020707@aitel.hist.no> <20061012112938.97ef924c.akpm@osdl.org> <452F906F.8020302@aitel.hist.no> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1677 Lines: 48 On Fri, 13 Oct 2006 15:11:11 +0200 Helge Hafting wrote: > Andrew Morton wrote: > > On Thu, 12 Oct 2006 14:18:04 +0200 > > Helge Hafting wrote: > > > > > >> I found an easy way to hang the kernel when copying a SD-card: > >> > >> dd if=/dev/sdc of=file bs=1048576 > >> > >> I.e. copy the entire 256MB card in 1MB chunks. I got about > >> 160MB before the kernel hung. Not even sysrq+B worked, I needed > >> the reset button. The pc has a total of 512MB memory if that matters. > >> > >> Using bs=4096 instead let me copy the entire card with no problems, > >> but that seems to progress slower. > >> > >> The above 'dd' command hangs my office pc every time. So I can repeat > >> it for debugging purposes. > >> > >> > > > > What device driver is providing /dev/sdc? > > > It is an usb card reader, so it is "usb mass storage" > and "scsi disk". > > Did any previous kernels work correctly? If so, which? > > > > I just got that card reader, so I haven't tested any earlier kernels. > I have another machine with a card reader, which I have used for > a long time. But I only ever copy files with "cp" on that one. > > This time I used "dd" to get an image of the entire card, and got trouble > when using 1M chunks. > > I can try with verbose scsi debug messages if that might help? > Maybe. The first step is to tell the developers. (adds cc). - 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/