Comment 0 for bug 1021471

I'm not sure how I triggered this. I've been moving around between networks and suspending/resuming all day.

Earlier in this boot I successfully used a container (start, networking and stop). I came to start the same one later and noticed that it didn't come up. Trying to attach to the console with lxc-console informed me that it wasn't running. I then saw suspicious content in dmesg:

[25800.412234] INFO: task lxc-start:25817 blocked for more than 120 seconds.
[25800.412243] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[25800.412254] lxc-start D ffff88013fd13980 0 25817 1 0x00000000
[25800.412266] ffff880007b43cc0 0000000000000086 ffff88003ba4c500 ffff880007b43fd8
[25800.412275] ffff880007b43fd8 ffff880007b43fd8 ffff880134c65c00 ffff88003ba4c500
[25800.412284] 000080d0ffffffff ffffffff81ca7c00 ffff88003ba4c500 ffffffff81ca7c04
[25800.412288] Call Trace:
[25800.412306] [<ffffffff81673759>] schedule+0x29/0x70
[25800.412313] [<ffffffff81673a1e>] schedule_preempt_disabled+0xe/0x10
[25800.412323] [<ffffffff81672537>] __mutex_lock_slowpath+0xd7/0x150
[25800.412331] [<ffffffff8167200a>] mutex_lock+0x2a/0x50
[25800.412340] [<ffffffff8155ede1>] copy_net_ns+0x71/0x100
[25800.412350] [<ffffffff8107adfb>] create_new_namespaces+0xdb/0x190
[25800.412357] [<ffffffff8107afec>] copy_namespaces+0x8c/0xd0
[25800.412367] [<ffffffff81050142>] copy_process.part.22+0x902/0x1520
[25800.412375] [<ffffffff81050ee5>] do_fork+0x135/0x390
[25800.412385] [<ffffffff8116db40>] ? kmem_cache_free+0x20/0x100
[25800.412395] [<ffffffff8118c6b3>] ? putname+0x33/0x50
[25800.412402] [<ffffffff811811cc>] ? do_sys_open+0x16c/0x200
[25800.412410] [<ffffffff8101c238>] sys_clone+0x28/0x30
[25800.412418] [<ffffffff8167cbf3>] stub_clone+0x13/0x20
[25800.412424] [<ffffffff8167c8e9>] ? system_call_fastpath+0x16/0x1b
[25806.312385] unregister_netdevice: waiting for lo to become free. Usage count = 1

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: linux-image-generic 3.5.0.3.3
ProcVersionSignature: Ubuntu 3.5.0-2.2-generic 3.5.0-rc4
Uname: Linux 3.5.0-2-generic x86_64
NonfreeKernelModules: nvidia wl
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.25.
ApportVersion: 2.2.5-0ubuntu2
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: NVidia [HDA NVidia], device 0: Cirrus Analog [Cirrus Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: laney 2787 F.... pulseaudio
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Card0.Amixer.info:
 Card hw:0 'NVidia'/'HDA NVidia at 0xd3480000 irq 22'
   Mixer name : 'Nvidia MCP89 HDMI'
   Components : 'HDA:10134206,106b0d00,00100301 HDA:10de000c,10de0101,00100200'
   Controls : 37
   Simple ctrls : 13
Date: Thu Jul 5 21:26:08 2012
HibernationDevice: RESUME=UUID=1c5b3f2c-2c89-4fa1-9ed8-0e238de8fe47
InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release amd64 (20100729)
MachineType: Apple Inc. MacBookPro7,1
ProcFB: 0 VESA VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-2-generic root=UUID=2228fdfe-3834-40b2-b7b4-efea7463e3c1 ro quiet splash reboot=pci vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.5.0-2-generic N/A
 linux-backports-modules-3.5.0-2-generic N/A
 linux-firmware 1.82
SourcePackage: linux
UpgradeStatus: Upgraded to quantal on 2012-01-13 (173 days ago)
dmi.bios.date: 03/25/10
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP71.88Z.0039.B05.1003251322
dmi.board.name: Mac-F222BEC8
dmi.board.vendor: Apple Inc.
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-F222BEC8
dmi.modalias: dmi:bvnAppleInc.:bvrMBP71.88Z.0039.B05.1003251322:bd03/25/10:svnAppleInc.:pnMacBookPro7,1:pvr1.0:rvnAppleInc.:rnMac-F222BEC8:rvr:cvnAppleInc.:ct10:cvrMac-F222BEC8:
dmi.product.name: MacBookPro7,1
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.