kernel-packages team mailing list archive

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

Otto Kekäläinen, 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.

** Tags added: bios-outdated-a13 regression-potential

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

-- 
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https://bugs.launchpad.net/bugs/998204

Title:
  Intel chipset driver bug on Ubuntu certified Dell Latitude E5420:
  connecting power cord makes kworker run amok

Status in “linux” package in Ubuntu:
  Incomplete

Bug description:
  I've noticed that sometimes when I'm running on battery and then
  insert the power cord, the system slows down significantly. When I
  remove the power cord, it runs fine again, and when I reattach the
  power cord the system slows down again.

  I'm running the latest Ubuntu 12.04 with all updates on a pre-
  installed Dell Latitude E5420 that is supposed to work perfectly with
  Ubuntu, since it is officially certified.

  While the sluggishness happens, running 'top' shows several kworker processes:
  top - 21:29:24 up 14:01,  4 users,  load average: 1.91, 2.16, 2.06
  Tasks: 208 total,   3 running, 202 sleeping,   0 stopped,   3 zombie
  Cpu(s):  5.6%us,  2.2%sy,  0.0%ni, 91.7%id,  0.5%wa,  0.0%hi,  0.0%si,  0.0%st
  Mem:   1891244k total,  1782568k used,   108676k free,    22512k buffers
  Swap:  2004988k total,   812400k used,  1192588k free,   550600k cached

    PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                  
  16561 otto      20   0  526m  15m 7796 S   14  0.9   1:10.79 gnome-system-mo                                                          
  16534 root      20   0     0    0    0 R    7  0.0   0:16.66 kworker/1:2                                                              
   1215 root      20   0  275m  25m 4472 S    6  1.4  11:31.39 Xorg                                                                     
  16362 root      20   0     0    0    0 S    3  0.0   0:10.00 kworker/0:1                                                              
   1889 otto      20   0 1470m  64m  12m S    3  3.5  10:07.92 compiz                                                                   
  16287 root      20   0     0    0    0 S    3  0.0   0:13.85 kworker/3:2                                                              
   2306 otto      20   0  652m  14m 5056 S    2  0.8   0:31.76 gnome-terminal                                                           
  17304 otto      20   0 17480 1384  964 R    1  0.1   0:00.03 top

  Using commands
  sudo perf record -ag sleep 30
  sudo perf report
  I was able to find out that the kworker threads running amok are due to the Intel I2C driver:
  ...
   2.91%      kworker/1:2  [kernel.kallsyms]                    [k] na
                  |
                  --- native_read_tsc
                     |          
                     |--62.97%-- delay_tsc
                     |          |          
                     |          |--53.92%-- __udelay
                     |          |          |          
                     |          |          |--50.48%-- sclhi
                     |          |          |          |          
                     |          |          |          |--94.88%-- i2c_outb
  ...
   2.76%      kworker/1:0  [kernel.kallsyms]                    [k] na
                  |
                  --- native_read_tsc
                     |          
                     |--69.42%-- delay_tsc
                     |          |          
                     |          |--58.89%-- __udelay
                     |          |          |          
                     |          |          |--47.38%-- sclhi
                     |          |          |          |          
                     |          |          |          |--88.80%-- i2c_outb
  ...
       2.20%      kworker/0:0  [kernel.kallsyms]                    [k] na
                  |
                  --- native_read_tsc
                     |          
                     |--64.58%-- delay_tsc
                     |          |          
                     |          |--63.38%-- __udelay
                     |          |          |          
                     |          |          |--47.18%-- i2c_outb.isra.4
                     |          |          |          try_address
                     |          |          |          bit_doAddress.isra.7
                     |          |          |          bit_xfer
                     |          |          |          intel_i2c_quirk_xfer
  ...

  I've attached the entire perf report output for your analysis.

  To view the stack of the process I ran cat /proc/16287/stack >
  pid-16287-stack.txt, which is also attached.

  
  Please fix the Intel driver so that it does not spawn any wild kworker processes and publish the fix in the 12.04 mainline kernel. I've noticed that others have this sympoms too, but I guess few are knowledgeable enough to file a proper bug report, so I decided to do one. For example, see comment #27 at https://bugs.launchpad.net/ubuntu/+source/linux/+bug/887793/comments/27 or http://askubuntu.com/questions/106187/lenovo-thinkpad-l520-slows-down-when-ac-power-adapter-is-plugged-in

  ProblemType: Bug
  DistroRelease: Ubuntu 12.04
  Package: linux-image-3.2.0-24-generic 3.2.0-24.37
  ProcVersionSignature: Ubuntu 3.2.0-24.37-generic 3.2.14
  Uname: Linux 3.2.0-24-generic x86_64
  AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
  ApportVersion: 2.0.1-0ubuntu7
  Architecture: amd64
  ArecordDevices:
   **** List of CAPTURE Hardware Devices ****
   card 0: PCH [HDA Intel PCH], device 0: STAC92xx Analog [STAC92xx Analog]
     Subdevices: 1/1
     Subdevice #0: subdevice #0
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC0:  otto       1897 F.... pulseaudio
  Card0.Amixer.info:
   Card hw:0 'PCH'/'HDA Intel PCH at 0x93d40000 irq 44'
     Mixer name	: 'Intel CougarPoint HDMI'
     Components	: 'HDA:111d76e7,1028049b,00100102 HDA:80862805,80860101,00100000'
     Controls      : 37
     Simple ctrls  : 13
  CheckboxSubmission: d8cea1222d756fdd8d727e88eb0e4a11
  CheckboxSystem: d00f84de8a555815fa1c4660280da308
  Date: Fri May 11 22:05:56 2012
  EcryptfsInUse: Yes
  HibernationDevice: RESUME=UUID=affcc5fa-3b4d-40de-aec2-259585dbd9e3
  InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Beta amd64 (20110413)
  MachineType: Dell Inc. Latitude E5420
  ProcFB: 0 inteldrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-24-generic root=UUID=0fc070a9-5f2c-41fc-b8f0-6e0a91fa1426 ro quiet i915.semaphores=1 pcie_aspm=force
  PulseList:
   Error: command ['pacmd', 'list'] failed with exit code 1: Home directory /home/otto not ours.
   No PulseAudio daemon running, or not running as session daemon.
  RelatedPackageVersions:
   linux-restricted-modules-3.2.0-24-generic N/A
   linux-backports-modules-3.2.0-24-generic  N/A
   linux-firmware                            1.79
  SourcePackage: linux
  StagingDrivers: mei
  UpgradeStatus: Upgraded to precise on 2012-04-09 (31 days ago)
  dmi.bios.date: 02/22/2011
  dmi.bios.vendor: Dell Inc.
  dmi.bios.version: A00
  dmi.board.name: 08N8FC
  dmi.board.vendor: Dell Inc.
  dmi.board.version: A01
  dmi.chassis.type: 9
  dmi.chassis.vendor: Dell Inc.
  dmi.modalias: dmi:bvnDellInc.:bvrA00:bd02/22/2011:svnDellInc.:pnLatitudeE5420:pvr01:rvnDellInc.:rn08N8FC:rvrA01:cvnDellInc.:ct9:cvr:
  dmi.product.name: Latitude E5420
  dmi.product.version: 01
  dmi.sys.vendor: Dell Inc.

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