Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754158AbYJNQBa (ORCPT ); Tue, 14 Oct 2008 12:01:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753842AbYJNQBF (ORCPT ); Tue, 14 Oct 2008 12:01:05 -0400 Received: from terminus.zytor.com ([198.137.202.10]:55135 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753762AbYJNQBB (ORCPT ); Tue, 14 Oct 2008 12:01:01 -0400 Message-ID: <48F4C237.2060103@zytor.com> Date: Tue, 14 Oct 2008 09:00:55 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: James Bottomley CC: Linux Kernel Mailing List , linux-scsi , James Bottomley Subject: Re: Checkin 7404ad3b6d04efbd918e9e2e776bf560fbedf47d breaks boot on KVM References: <48F3E1C9.6030007@zytor.com> <1223990609.12440.8.camel@localhost.localdomain> In-Reply-To: <1223990609.12440.8.camel@localhost.localdomain> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4910 Lines: 152 James Bottomley wrote: >> > Actually, it is surprising. That patch takes the default arithmetic for > calculating the disk size out of sd and uses a routine to do it more > efficiently in lib/string_helpers.c > > So there are two problems: Why does it panic on revert (could you post > the oops) and what does kvm object to in string_get_size ... it's a > fairly innocuous routine as I read it ... your symptoms sound like the > for loop isn't terminating. > Here is the oops. Note that it does get well past the hang point before it crashes. It is 100% reproducible. console [netcon0] enabled netconsole: network logging started Uniform Multi-Platform E-IDE driver ide-floppy driver 1.00 Driver 'sd' needs updating - please use bus_type methods scsi0 : ata_piix scsi1 : ata_piix ata1: PATA max MWDMA2 cmd 0x1f0 ctl 0x3f6 bmdma 0xc000 irq 14 ata2: PATA max MWDMA2 cmd 0x170 ctl 0x376 bmdma 0xc008 irq 15 ata1.00: ATA-7: QEMU HARDDISK, 0.9.1, max UDMA/100 ata1.00: 16777216 sectors, multi 16: LBA48 ata1.00: configured for MWDMA2 ata2.00: ATAPI: QEMU DVD-ROM, 0.9.1, max UDMA/100 ata2.00: configured for MWDMA2 scsi 0:0:0:0: Direct-Access ATA QEMU HARDDISK 0.9. PQ: 0 ANSI: 5 sd 0:0:0:0: [sda] 16777216 512-byte hardware sectors (8590 MB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA sd 0:0:0:0: [sda] 16777216 512-byte hardware sectors (8590 MB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA sda: sda1 sd 0:0:0:0: [sda] Attached SCSI disk scsi 1:0:0:0: CD-ROM QEMU QEMU DVD-ROM 0.9. PQ: 0 ANSI: 5 PNP: PS/2 Controller [PNP0303:KBD,PNP0f13:MOU] at 0x60,0x64 irq 1,12 serio: i8042 KBD port at 0x60,0x64 irq 1 serio: i8042 AUX port at 0x60,0x64 irq 12 mice: PS/2 mouse device common for all mice input: AT Translated Set 2 keyboard as /class/input/input0 md: linear personality registered for level -1 md: raid0 personality registered for level 0 md: raid1 personality registered for level 1 md: raid10 personality registered for level 10 raid6: int32x1 972 MB/s raid6: int32x2 1032 MB/s raid6: int32x4 763 MB/s raid6: int32x8 729 MB/s raid6: mmxx1 2572 MB/s raid6: mmxx2 3154 MB/s raid6: sse1x1 2036 MB/s raid6: sse1x2 2430 MB/s raid6: sse2x1 3506 MB/s raid6: sse2x2 3428 MB/s raid6: using algorithm sse2x1 (3506 MB/s) md: raid6 personality registered for level 6 md: raid5 personality registered for level 5 md: raid4 personality registered for level 4 EDAC MC: Ver: 2.1.0 Oct 13 2008 input: ImExPS/2 Generic Explorer Mouse as /class/input/input1 dcdbas dcdbas: Dell Systems Management Base Driver (version 5.6.0-3.2) usbcore: registered new interface driver hiddev usbcore: registered new interface driver usbhid usbhid: v2.6:USB HID core driver TCP cubic registered NET: Registered protocol family 17 RPC: Registered udp transport module. RPC: Registered tcp transport module. Using IPI Shortcut mode registered taskstats version 1 BIOS EDD facility v0.16 2004-Jun-25, 1 devices found md: Autodetecting RAID arrays. md: Scanned 0 and added 0 devices. md: autorun ... md: ... autorun DONE. kjournald starting. Commit interval 5 seconds EXT3-fs: mounted filesystem with ordered data mode. VFS: Mounted root (ext3 filesystem) readonly. Freeing unused kernel memory: 304k freed Write protecting the kernel text: 3692k Write protecting the kernel read-only data: 1556k BUG: spinlock bad magic on CPU#0, swapper/1 lock: c0b75418, .magic: 00000000, .owner: /-1, .owner_cpu: 0 Pid: 1, comm: swapper Not tainted 2.6.27 #17 Call Trace: [] ? printk+0xf/0x17 [] spin_bug+0x75/0x80 [] _raw_spin_lock+0x1e/0xe4 [] ? serial8250_startup+0x33e/0x4e5 [] _spin_lock_irq+0x32/0x3a [] ? serial8250_startup+0x33e/0x4e5 [] serial8250_startup+0x33e/0x4e5 [] uart_startup+0x84/0x143 [] uart_open+0x14b/0x381 [] ? _spin_unlock+0x27/0x3c [] ? check_tty_count+0x3b/0x8a [] tty_open+0x263/0x366 [] chrdev_open+0x168/0x180 [] __dentry_open+0x146/0x234 [] nameidata_to_filp+0x1f/0x33 [] ? chrdev_open+0x0/0x180 [] do_filp_open+0x342/0x659 [] ? trace_hardirqs_off+0xb/0xd [] ? _spin_unlock+0x27/0x3c [] do_sys_open+0x42/0xb7 [] sys_open+0x1e/0x26 [] init_post+0x2a/0x13c [] ? kernel_thread_helper+0x7/0x10 -- 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/