kernel-packages team mailing list archive

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

Daniel Hahler, thank you for reporting this and helping make Ubuntu
better. Could you please test the latest upstream kernel available from
the very top line at the top of the page from http://kernel.ubuntu.com
/~kernel-ppa/mainline/?C=N;O=D (the release names are irrelevant for
testing, and please do not test the daily folder)? Install instructions
are available at https://wiki.ubuntu.com/Kernel/MainlineBuilds . This
will allow additional upstream developers to examine the issue.

If the latest kernel did not allow you to test to the issue (ex. you couldn't boot into the OS) please make a comment in your report about this, and continue to test the next most recent kernel version until you can test to the issue. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this issue is fixed in the mainline kernel, please add the following tags by clicking on the yellow circle with a black pencil icon, next to the word Tags, located at the bottom of the report description:
kernel-fixed-upstream
kernel-fixed-upstream-X.Y-rcZ

Where X, Y, and Z are numbers corresponding to the kernel version.

If the mainline kernel does not fix the issue, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-X.Y-rcZ

Please note, an error to install the kernel does not fit the criteria of
kernel-bug-exists-upstream.

Once testing of the latest upstream kernel is complete, please mark this
report's Status as Confirmed. Please let us know your results.

Thank you for your understanding.

** Tags added: latest-bios-1.40

** Changed in: linux (Ubuntu)
   Importance: Undecided => Medium

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

-- 
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/1497520

Title:
  Slow performance after resuming from/on battery (CPUs do not scale
  above 800MHz)

Status in linux package in Ubuntu:
  Incomplete

Bug description:
  I have noticed slow performance after resuming from STR on battery.

  I can not trigger this always, but it seems to be related to
  suspending and resuming while on battery.

  The CPU scaling governors look like this then:

  % cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
  powersave
  performance
  performance
  performance

  % cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_driver 
  intel_pstate
  intel_pstate
  intel_pstate
  intel_pstate

  % cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq
  3200000
  3200000
  3200000
  3200000

  When watching the current CPU frequencies, it can be seen that they
  don't go above 800000 ('watch grep \"cpu MHz\" /proc/cpuinfo').

  I cannot see why they are limited to 800000.

  It looks like https://bugzilla.kernel.org/show_bug.cgi?id=61241, but
  /sys/devices/system/cpu/intel_pstate/max_perf_pct is at 100.

  Just writing the same setting for cpu0 again fixes it, and all CPUs
  will be scaled above 800MHz again:

  % echo powersave | sudo tee
  /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

  ProblemType: Bug
  DistroRelease: Ubuntu 15.04
  Package: linux-image-3.19.0-28-generic 3.19.0-28.30
  ProcVersionSignature: Ubuntu 3.19.0-28.30-generic 3.19.8-ckt5
  Uname: Linux 3.19.0-28-generic x86_64
  ApportVersion: 2.17.2-0ubuntu1.4
  Architecture: amd64
  CurrentDesktop: Unity
  Date: Sat Sep 19 10:39:02 2015
  HibernationDevice: RESUME=UUID=d39463f5-889e-42ba-a729-f3f442f0c8dd
  InstallationDate: Installed on 2012-05-28 (1208 days ago)
  InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
  MachineType: LENOVO 42992PG
  ProcFB: 0 inteldrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.19.0-28-generic root=/dev/mapper/vg0-rootlv ro quiet splash
  RelatedPackageVersions:
   linux-restricted-modules-3.19.0-28-generic N/A
   linux-backports-modules-3.19.0-28-generic  N/A
   linux-firmware                             1.143.3
  SourcePackage: linux
  UpgradeStatus: Upgraded to vivid on 2015-05-14 (127 days ago)
  dmi.bios.date: 05/14/2015
  dmi.bios.vendor: LENOVO
  dmi.bios.version: 8DET70WW (1.40 )
  dmi.board.asset.tag: Not Available
  dmi.board.name: 42992PG
  dmi.board.vendor: LENOVO
  dmi.board.version: Not Available
  dmi.chassis.asset.tag: No Asset Information
  dmi.chassis.type: 10
  dmi.chassis.vendor: LENOVO
  dmi.chassis.version: Not Available
  dmi.modalias: dmi:bvnLENOVO:bvr8DET70WW(1.40):bd05/14/2015:svnLENOVO:pn42992PG:pvrThinkPadX220Tablet:rvnLENOVO:rn42992PG:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
  dmi.product.name: 42992PG
  dmi.product.version: ThinkPad X220 Tablet
  dmi.sys.vendor: LENOVO

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1497520/+subscriptions