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[Brad Figg <brad.figg@xxxxxxxxxxxxx>]

This bug is missing log files that will aid in diagnosing the problem.
>From a terminal window please run:

apport-collect 1413540

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable
to run this command, please add a comment stating that fact and change
the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the
Ubuntu Kernel Team.

** Changed in: linux (Ubuntu)
       Status: New => Incomplete

** Tags added: trusty

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https://bugs.launchpad.net/bugs/1413540

Title:
  qemu-kvm package enables KSM on VMs

Status in linux package in Ubuntu:
  Incomplete
Status in qemu package in Ubuntu:
  Confirmed

Bug description:
  When installing qemu-kvm on a VM, KSM is enabled.

  I have encountered this problem in trusty:$ lsb_release -a
  Distributor ID: Ubuntu
  Description:    Ubuntu 14.04.1 LTS
  Release:        14.04
  Codename:       trusty
  $ uname -a
  Linux juju-gema-machine-2 3.13.0-40-generic #69-Ubuntu SMP Thu Nov 13 17:53:56 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

  The way to see the behaviour:
  1) $ more /sys/kernel/mm/ksm/run
  0
  2) $ sudo apt-get install qemu-kvm
  3) $ more /sys/kernel/mm/ksm/run
  1

  To see the soft lockups, deploy a cloud on a virtualised env like ctsstack, run tempest on it, the compute nodes of the virtualised deployment will eventually stop responding with (run tempest 2 times at least):
   24096.072003] BUG: soft lockup - CPU#0 stuck for 23s! [qemu-system-x86:24791]
  [24124.072003] BUG: soft lockup - CPU#0 stuck for 23s! [qemu-system-x86:24791]
  [24152.072002] BUG: soft lockup - CPU#0 stuck for 22s! [qemu-system-x86:24791]
  [24180.072003] BUG: soft lockup - CPU#0 stuck for 22s! [qemu-system-x86:24791]
  [24208.072004] BUG: soft lockup - CPU#0 stuck for 22s! [qemu-system-x86:24791]
  [24236.072004] BUG: soft lockup - CPU#0 stuck for 22s! [qemu-system-x86:24791]
  [24264.072003] BUG: soft lockup - CPU#0 stuck for 22s! [qemu-system-x86:24791]

  I am not sure whether the problem is that we are enabling KSM on a VM
  or the problem is that nested KSM is not behaving properly. Either way
  I can easily reproduce, please contact me if you need further details.

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