kernel-packages team mailing list archive

[Parameswaran Sivatharman <para.siva@xxxxxxxxxxxxx>]

This bug does not exist any more. Sorry for the delayed response. I'll
mark it as Fix Released. Thanks for the time on this.

** Changed in: linux (Ubuntu Saucy)
       Status: Incomplete => Fix Released

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https://bugs.launchpad.net/bugs/1181315

Title:
  unregister_netdevice: waiting for lo to become free. Usage count = 2'
  is reported and causing kernel hang when floodlight tests are run
  using utah

Status in “linux” package in Ubuntu:
  Fix Released
Status in “linux” source package in Saucy:
  Fix Released

Bug description:
  When utah client is used to run floodlight smoke tests for saucy
  server images, the following error is reported.

  May 17 17:41:13 ubuntu kernel: [  618.483362] IPv6: ADDRCONF(NETDEV_UP): s1-eth1: link is not ready
  May 17 17:41:23 ubuntu kernel: [  628.220062] unregister_netdevice: waiting for lo to become free. Usage count = 2
  May 17 17:41:33 ubuntu kernel: [  638.460029] unregister_netdevice: waiting for lo to become free. Usage count = 2
  ....
  ...
  ...
  May 17 17:44:16 ubuntu kernel: [  801.760026] unregister_netdevice: waiting for lo to become free. Usage count = 2
  May 17 17:44:27 ubuntu kernel: [  812.000029] unregister_netdevice: waiting for lo to become free. Usage count = 2
  May 17 17:44:37 ubuntu kernel: [  822.240031] unregister_netdevice: waiting for lo to become free. Usage count = 2
  May 17 17:44:47 ubuntu kernel: [  832.480024] unregister_netdevice: waiting for lo to become free. Usage count = 2
  May 17 17:44:55 ubuntu kernel: [  840.564053] INFO: task mnexec:9343 blocked for more than 120 seconds.
  May 17 17:44:55 ubuntu kernel: [  840.564268] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  May 17 17:44:55 ubuntu kernel: [  840.564494] mnexec          D ffff88003fc14240     0  9343   8358 0x00000000
  May 17 17:44:55 ubuntu kernel: [  840.564498]  ffff880036c3fe20 0000000000000046 ffff880036c3ffd8 0000000000014240
  May 17 17:44:55 ubuntu kernel: [  840.564501]  ffff880036c3ffd8 0000000000014240 ffff88003c1add40 ffffffff81ccea60
  May 17 17:44:55 ubuntu kernel: [  840.564503]  ffff88003c1add40 ffffffff81ccea64 00000000ffffffff ffffffff81ccea68
  May 17 17:44:55 ubuntu kernel: [  840.564506] Call Trace:
  May 17 17:44:55 ubuntu kernel: [  840.564531]  [<ffffffff816d1499>] schedule_preempt_disabled+0x29/0x70
  May 17 17:44:55 ubuntu kernel: [  840.564535]  [<ffffffff816cf537>] __mutex_lock_slowpath+0xe7/0x160
  May 17 17:44:55 ubuntu kernel: [  840.564550]  [<ffffffff8117cbcf>] ? __kmalloc+0x14f/0x180
  May 17 17:44:55 ubuntu kernel: [  840.564554]  [<ffffffff816cefbf>] mutex_lock+0x1f/0x30
  May 17 17:44:55 ubuntu kernel: [  840.564564]  [<ffffffff815c5e05>] copy_net_ns+0x65/0x100
  May 17 17:44:55 ubuntu kernel: [  840.564574]  [<ffffffff810814e9>] create_new_namespaces+0xf9/0x180
  May 17 17:44:55 ubuntu kernel: [  840.564577]  [<ffffffff81081731>] unshare_nsproxy_namespaces+0x61/0xa0
  May 17 17:44:55 ubuntu kernel: [  840.564582]  [<ffffffff81057b41>] sys_unshare+0x181/0x2a0
  May 17 17:44:55 ubuntu kernel: [  840.564585]  [<ffffffff816da99d>] system_call_fastpath+0x1a/0x1f

  ================================================
  This is observed to occur only when utah is used to run the floodlight smoke tests.  Running the floodlight tests without utah does not cause this issue and using utah to run some other tests does not cause this issue either.

  Noticed a similar bug 1021471, but this one is occurring in KVM using
  libvirt.

  The issue is only with the saucy kernel versions, 3.9.0-1 onwards and
  does not occur with 3.9.0-0. The tests were tried with saucy server
  VMs on precise as well as saucy hosts and the results is the same.

  ================
  Steps to reproduce:
  1. Install a default saucy server on a vm  (either manually or preseeded default installation) with either i386 or amd64 image using KVM, libvirt
  2. Do the following to install utah inside the VM
     sudo apt-add-repository -y ppa:utah/stable
     sudo apt-get update
     sudo apt-get install utah
  3. Run the floodlight tests using
       sudo utah -r  lp:ubuntu-test-cases/server/runlists/floodlight.run
  4. Now "kernel: [  358.452029]  unregister_netdevice: waiting for lo to become free. Usage count = 2" will be continuously reported

  The impacted jobs are,
  https://jenkins.qa.ubuntu.com/view/Saucy/view/Smoke%20Testing/job/saucy-server-amd64-smoke-floodlight/15/
  and
  https://jenkins.qa.ubuntu.com/view/Saucy/view/Smoke%20Testing/job/saucy-server-i386-smoke-floodlight/13/

  ProblemType: Bug
  DistroRelease: Ubuntu 13.10
  Package: linux-image-3.9.0-2-generic 3.9.0-2.6
  ProcVersionSignature: Ubuntu 3.9.0-2.6-generic 3.9.2
  Uname: Linux 3.9.0-2-generic x86_64
  AlsaVersion: Advanced Linux Sound Architecture Driver Version k3.9.0-2-generic.
  AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
  ApportVersion: 2.10.1-0ubuntu1
  Architecture: amd64
  ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
  AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path', '/dev/snd/controlC0', '/dev/snd/hwC0D0', '/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
  CRDA: Error: [Errno 2] No such file or directory: 'iw'
  Card0.Amixer.info: Error: [Errno 2] No such file or directory: 'amixer'
  Card0.Amixer.values: Error: [Errno 2] No such file or directory: 'amixer'
  Date: Fri May 17 17:53:02 2013
  HibernationDevice: RESUME=UUID=a9b2a509-9179-44d3-a4ea-807f7cd05d4e
  InstallationDate: Installed on 2013-05-17 (0 days ago)
  InstallationMedia: Ubuntu-Server 13.10 "Saucy Salamander" - Alpha amd64 (20130517)
  Lsusb: Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
  MachineType: Bochs Bochs
  MarkForUpload: True
  ProcFB:

  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.9.0-2-generic root=UUID=810403bd-1b5c-4a51-bc07-6ce34be38cd9 nomodeset ro
  RelatedPackageVersions:
   linux-restricted-modules-3.9.0-2-generic N/A
   linux-backports-modules-3.9.0-2-generic  N/A
   linux-firmware                           1.108
  RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 01/01/2011
  dmi.bios.vendor: Bochs
  dmi.bios.version: Bochs
  dmi.chassis.type: 1
  dmi.chassis.vendor: Bochs
  dmi.modalias: dmi:bvnBochs:bvrBochs:bd01/01/2011:svnBochs:pnBochs:pvr:cvnBochs:ct1:cvr:
  dmi.product.name: Bochs
  dmi.sys.vendor: Bochs

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