Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 1 Mar 2002 15:06:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 1 Mar 2002 15:06:19 -0500 Received: from mail.myrio.com ([63.109.146.2]:25334 "HELO mail.myrio.com") by vger.kernel.org with SMTP id convert rfc822-to-8bit; Fri, 1 Mar 2002 15:06:02 -0500 X-MimeOLE: Produced By Microsoft Exchange V6.0.5762.3 content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Subject: RE: Multiple kernels OOPS at boot on Fujitsu pt510 ( AMD DX100 CPU ) - ksymoops output attached Date: Fri, 1 Mar 2002 12:04:23 -0800 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: Multiple kernels OOPS at boot on Fujitsu pt510 ( AMD DX100 CPU ) - ksymoops output attached Thread-Index: AcHBVi/IuduQgUkSTrCa62hDlL6B3gAAphLw From: "Torrey Hoffman" To: Cc: "Zwane Mwaikambo" , "Matthew Allum" , X-OriginalArrivalTime: 01 Mar 2002 20:05:17.0903 (UTC) FILETIME=[689805F0:01C1C15C] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Richard B. Johnson [mailto:root@chaos.analogic.com] wrote: >This is on 2.4.17. Once I am up, I can build an ext2 file-system ramdisk- >image. I can mount it though the loop device and I can read/write to Beware of ramdisks on 2.4.17! This kernel has the bug I mentioned. It appeared with the new VM in 2.4.10 and was fixed in 2.4.18-pre4. (I will try out your script on whatever I'm running at the moment.) The bug has to do with the difference in how the ramdisk driver allocated (or failed to allocate) pages when accessed directly as a block device, or indirectly through a filesystem. For much more detail, search in the archives for a subject line: "ramdisk corruption problems - was: RE: pivot_root and initrd". If you must use 2.4.17, the workaround is to dd from /dev/zero to /dev/ram0 before running mke2fs, thereby "initializing" all the blocks of the device. The following is a test script which tickled the bug, with the workaround. - - - - - - #!/bin/bash # this script assumes /mnt/ramdisk is a valid mountpoint # ./testdir should have 3-4 MB of reasonably large files. # freeramdisk is a program that sends the ioctl to deallocate # the ramdisk. Not needed unless you are running this test # after already using the ramdisk. ../rootfs/sbin/freeramdisk /dev/ram0 # this dd is the workaround. Leave it out to check for the bug #dd if=/dev/zero of=/dev/ram0 bs=1k count=4000 mke2fs -m0 /dev/ram0 4000 mount -t ext2 /dev/ram0 /mnt/ramdisk rm -rf /mnt/ramdisk/* cp -a ./testdir /mnt/ramdisk umount /dev/ram0 dd if=/dev/ram0 of=ram0.img bs=1k count=4000 dd if=ram0.img of=/dev/ram0 bs=1k count=4000 mount -t ext2 /dev/ram0 /mnt/ramdisk # if this diff returns anything, your kernel has the bug. diff -q -r ./testdir /mnt/ramdisk/testdir umount /dev/ram0 - - - - - - Torrey Hoffman - 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/