Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751717AbWJMNOj (ORCPT ); Fri, 13 Oct 2006 09:14:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751719AbWJMNOj (ORCPT ); Fri, 13 Oct 2006 09:14:39 -0400 Received: from embla.aitel.hist.no ([158.38.50.22]:28544 "HELO embla.aitel.hist.no") by vger.kernel.org with SMTP id S1751717AbWJMNOi (ORCPT ); Fri, 13 Oct 2006 09:14:38 -0400 Message-ID: <452F906F.8020302@aitel.hist.no> Date: Fri, 13 Oct 2006 15:11:11 +0200 From: Helge Hafting User-Agent: Thunderbird 1.5.0.7 (X11/20060915) MIME-Version: 1.0 To: Andrew Morton CC: linux-kernel@vger.kernel.org Subject: Re: 2.6.19-rc1-mm1 - locks when using "dd bs=1M" from card reader References: <20061010000928.9d2d519a.akpm@osdl.org> <452E327C.9020707@aitel.hist.no> <20061012112938.97ef924c.akpm@osdl.org> In-Reply-To: <20061012112938.97ef924c.akpm@osdl.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1469 Lines: 45 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? Helge Hafting - 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/