kernel-packages team mailing list archive

["Samuel D. Leslie" <sdl@xxxxxxxxxx>]

This bug has been quiet for a while by the looks of it so just chipping
in. I can confirm I witnessed this bug last week on an Ubuntu 14.04 x64
VM on a Windows Server 2012 R2 Hyper-V server with dynamic memory
enabled on the guest. I suspect that dynamic memory (aka. memory hot-
add/remove) may be related to this issue. If so, creating a VM with
dynamic memory enabled and then running a workload that is memory
intensive to ensure the Hyper-V server allocates more RAM to the VM may
be beneficial. The tie-in with the balloon driver is interesting, and
might suggest there's some level of interaction going on between these
two components? Perhaps after dynamic memory adds more RAM to the system
the balloon driver may trigger the issue due to no longer valid
assumptions, or alternatively, the removal of memory from the system
once it no longer needs it has a similar effect?

It may also be useful for others to know that we initially detected this
issue due to it causing a very high load average on the affected system
which can be trivially detected by monitoring systems like Nagios. Note
that while the load average is high, this doesn't correspond to any
given process actually consuming substantial CPU resources, so you'll
want to take a look at the dmesg output which will confirm if you're
experiencing the issue via the blocked systemd-udevd and kworker
processes.

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1292400

Title:
  task systemd-udevd:1906 blocked for more than 120 seconds.

Status in “linux” package in Ubuntu:
  Confirmed

Bug description:
  System log shows repeated incidents of "task systemd-udevd:1906
  blocked for more than 120 seconds."

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: linux-image-3.13.0-17-generic 3.13.0-17.37 [modified: boot/vmlinuz-3.13.0-17-generic]
  ProcVersionSignature: Ubuntu 3.13.0-17.37-generic 3.13.6
  Uname: Linux 3.13.0-17-generic x86_64
  ApportVersion: 2.13.3-0ubuntu1
  Architecture: amd64
  AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
  CurrentDesktop: XFCE
  Date: Fri Mar 14 08:54:36 2014
  HibernationDevice: RESUME=UUID=0d223c65-8c7e-41b4-95b3-05b22ff4679b
  InstallationDate: Installed on 2014-03-12 (1 days ago)
  InstallationMedia: Xubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140312)
  IwConfig:
   eth0      no wireless extensions.
   
   lo        no wireless extensions.
  Lspci:
   
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize libusb: -99
  MachineType: Microsoft Corporation Virtual Machine
  ProcFB: 0 EFI VGA
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-17-generic.efi.signed root=UUID=61b52c1b-300d-4c30-8966-db1745f4a4bc ro video:hyperv_fb=1920x1080 quiet splash vt.handoff=7
  RelatedPackageVersions:
   linux-restricted-modules-3.13.0-17-generic N/A
   linux-backports-modules-3.13.0-17-generic  N/A
   linux-firmware                             1.126
  RfKill:
   
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 11/26/2012
  dmi.bios.vendor: Microsoft Corporation
  dmi.bios.version: Hyper-V UEFI Release v1.0
  dmi.board.asset.tag: None
  dmi.board.name: Virtual Machine
  dmi.board.vendor: Microsoft Corporation
  dmi.board.version: Hyper-V UEFI Release v1.0
  dmi.chassis.asset.tag: 6485-6574-9248-6162-4701-6267-50
  dmi.chassis.type: 3
  dmi.chassis.vendor: Microsoft Corporation
  dmi.chassis.version: Hyper-V UEFI Release v1.0
  dmi.modalias: dmi:bvnMicrosoftCorporation:bvrHyper-VUEFIReleasev1.0:bd11/26/2012:svnMicrosoftCorporation:pnVirtualMachine:pvrHyper-VUEFIReleasev1.0:rvnMicrosoftCorporation:rnVirtualMachine:rvrHyper-VUEFIReleasev1.0:cvnMicrosoftCorporation:ct3:cvrHyper-VUEFIReleasev1.0:
  dmi.product.name: Virtual Machine
  dmi.product.version: Hyper-V UEFI Release v1.0
  dmi.sys.vendor: Microsoft Corporation
  --- 
  ApportVersion: 2.13.3-0ubuntu1
  Architecture: amd64
  AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
  CurrentDesktop: XFCE
  DistroRelease: Ubuntu 14.04
  HibernationDevice: RESUME=UUID=0d223c65-8c7e-41b4-95b3-05b22ff4679b
  InstallationDate: Installed on 2014-03-12 (1 days ago)
  InstallationMedia: Xubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140312)
  IwConfig:
   eth0      no wireless extensions.
   
   lo        no wireless extensions.
  Lspci:
   
  Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to initialize libusb: -99
  MachineType: Microsoft Corporation Virtual Machine
  Package: linux (not installed)
  ProcFB: 0 EFI VGA
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-17-generic.efi.signed root=UUID=61b52c1b-300d-4c30-8966-db1745f4a4bc ro video:hyperv_fb=1920x1080 quiet splash vt.handoff=7
  ProcVersionSignature: Ubuntu 3.13.0-17.37-generic 3.13.6
  RelatedPackageVersions:
   linux-restricted-modules-3.13.0-17-generic N/A
   linux-backports-modules-3.13.0-17-generic  N/A
   linux-firmware                             1.126
  RfKill:
   
  Tags:  trusty
  Uname: Linux 3.13.0-17-generic x86_64
  UpgradeStatus: No upgrade log present (probably fresh install)
  UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
  _MarkForUpload: True
  dmi.bios.date: 11/26/2012
  dmi.bios.vendor: Microsoft Corporation
  dmi.bios.version: Hyper-V UEFI Release v1.0
  dmi.board.asset.tag: None
  dmi.board.name: Virtual Machine
  dmi.board.vendor: Microsoft Corporation
  dmi.board.version: Hyper-V UEFI Release v1.0
  dmi.chassis.asset.tag: 6485-6574-9248-6162-4701-6267-50
  dmi.chassis.type: 3
  dmi.chassis.vendor: Microsoft Corporation
  dmi.chassis.version: Hyper-V UEFI Release v1.0
  dmi.modalias: dmi:bvnMicrosoftCorporation:bvrHyper-VUEFIReleasev1.0:bd11/26/2012:svnMicrosoftCorporation:pnVirtualMachine:pvrHyper-VUEFIReleasev1.0:rvnMicrosoftCorporation:rnVirtualMachine:rvrHyper-VUEFIReleasev1.0:cvnMicrosoftCorporation:ct3:cvrHyper-VUEFIReleasev1.0:
  dmi.product.name: Virtual Machine
  dmi.product.version: Hyper-V UEFI Release v1.0
  dmi.sys.vendor: Microsoft Corporation

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1292400/+subscriptions