kernel-packages team mailing list archive

["Christopher M. Penalver" <christopher.m.penalver@xxxxxxxxx>]

Mio, this bug was reported a while ago and there hasn't been any
activity in it recently. We were wondering if this is still an issue? If
so, could you please test for this with the latest development release
of Ubuntu? ISO images are available from http://cdimage.ubuntu.com
/daily-live/current/ .

If it remains an issue, could you please run the following command in
the development release from a Terminal
(Applications->Accessories->Terminal), as it will automatically gather
and attach updated debug information to this report:

apport-collect -p linux <replace-with-bug-number>

Also, could you please test the latest upstream kernel available following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue. Please do not test the daily folder, but the one all the way at the bottom. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this bug is fixed in the mainline kernel, please add the following tags:
kernel-fixed-upstream
kernel-fixed-upstream-VERSION-NUMBER

where VERSION-NUMBER is the version number of the kernel you tested. For example:
kernel-fixed-upstream-v3.11-rc5

This can be done by clicking on the yellow circle with a black pencil icon next to the word Tags located at the bottom of the bug description. As well, please remove the tag:
needs-upstream-testing

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-VERSION-NUMBER

As well, please remove the tag:
needs-upstream-testing

Once testing of the upstream kernel is complete, please mark this bug's
Status as Confirmed. Please let us know your results. Thank you for your
understanding.

** This bug is no longer a duplicate of bug 887793
   Kworker constantly taking about 100% CPU

** Tags added: needs-full-computer-model needs-upstream-testing
regression-potential

-- 
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/1087010

Title:
  kworker uses 70-90% of a CPU core (hyperthreaded)

Status in “linux” package in Ubuntu:
  Incomplete

Bug description:
  I see high cpu usage from a kworker thread. Usually kworker/0:1 or kworker/0:2. I tested various kernels from Ubuntu and mainline (3.5.0-x, 3.6.x, 3.7.0-rcx) and they all showed the same behavior. This does not always happen.
  I wasn't able to determine on which basis it happens. Some observations that may as well be wrong (duh!):
  On some boot all is fine but once it shows, no matter how many reboots it does not seem to want to go away again.
  The laptop seems to have to rest a while to have a chance that it won't happen.
  If it does not happen a reboot will show the behavior.

  I saw similar bug reports in various places but it seems that this can
  have a multitude of causes and the presented workarounds or fixes did
  not apply to me.

  ProblemType: Bug
  DistroRelease: Ubuntu 12.10
  Package: linux-image-3.5.0-19-generic 3.5.0-19.30
  ProcVersionSignature: Ubuntu 3.5.0-19.30-generic 3.5.7
  Uname: Linux 3.5.0-19-generic x86_64
  ApportVersion: 2.6.1-0ubuntu6
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC0:  mio        1965 F.... pulseaudio
   /dev/snd/pcmC0D0p:   mio        1965 F...m pulseaudio
  Date: Wed Dec  5 22:37:00 2012
  HibernationDevice: RESUME=UUID=a371882c-0fe7-45e5-9adb-83da8374bc11
  InstallationDate: Installed on 2012-10-10 (55 days ago)
  InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1)
  MachineType: SAMSUNG ELECTRONICS CO., LTD. 700Z7C
  MarkForUpload: True
  ProcEnviron:
   TERM=xterm
   PATH=(custom, no user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 inteldrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-19-generic root=UUID=79674508-93de-43e0-b313-f6a9b480c606 ro crashkernel=384M-2G:64M,2G-:128M acpi_osi=Linux pcie_aspm=force i915.modeset=1 i915.i915_enable_rc6=1 i915.lvds_downclock=1 i915.semaphores=1 i915.powersave=1 snd_hda_intel.power_save_controller=1 snd_hda_intel.power_save=1 quiet splash vt.handoff=7
  PulseList:
   Error: command ['pacmd', 'list'] failed with exit code 1: Home directory /home/mio not ours.
   No PulseAudio daemon running, or not running as session daemon.
  RelatedPackageVersions:
   linux-restricted-modules-3.5.0-19-generic N/A
   linux-backports-modules-3.5.0-19-generic  N/A
   linux-firmware                            1.95
  SourcePackage: linux
  UpgradeStatus: Upgraded to quantal on 2012-10-11 (55 days ago)
  dmi.bios.date: 08/02/2012
  dmi.bios.vendor: Phoenix Technologies Ltd.
  dmi.bios.version: P04AAE
  dmi.board.asset.tag: Base Board Asset Tag
  dmi.board.name: SAMSUNG_NP1234567890
  dmi.board.vendor: SAMSUNG ELECTRONICS CO., LTD.
  dmi.board.version: FAB1
  dmi.chassis.asset.tag: No Asset Tag
  dmi.chassis.type: 9
  dmi.chassis.vendor: SAMSUNG ELECTRONICS CO., LTD.
  dmi.chassis.version: 0.1
  dmi.modalias: dmi:bvnPhoenixTechnologiesLtd.:bvrP04AAE:bd08/02/2012:svnSAMSUNGELECTRONICSCO.,LTD.:pn700Z7C:pvr0.1:rvnSAMSUNGELECTRONICSCO.,LTD.:rnSAMSUNG_NP1234567890:rvrFAB1:cvnSAMSUNGELECTRONICSCO.,LTD.:ct9:cvr0.1:
  dmi.product.name: 700Z7C
  dmi.product.version: 0.1
  dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD.

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