Just had this again. -- 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: Expired 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. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1087010/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
