kernel-packages team mailing list archive

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

Felix Kuehling, 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

If you are unable to test the mainline kernel, please comment as to why specifically you were unable to test it and add the following tags:
kernel-unable-to-test-upstream
kernel-unable-to-test-upstream-VERSION-NUMBER

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** Tags added: bios-outdated-2101

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

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https://bugs.launchpad.net/bugs/661411

Title:
  Multi-core load balancing not working properly after suspend to disk

Status in “linux” package in Ubuntu:
  Incomplete

Bug description:
  CPU: Intel(R) Core(TM) i7 CPU         860, 4 cores, hyperthreading

  Symptoms: After suspending to disk load balancing of processes across
  CPU cores is not working properly. Runnable processes have to share a
  CPU core even if idle CPU cores are available. This is particularly
  noticeable when running parallel builds (e.g. make -j8 ...). They take
  much longer and the GNOME system monitor applet shows that most CPU
  cores are idle when there is enough work to keep them all busy.

  A simple test to visualize the problem is to run "(while true; do
  true; done) & (while true; do true; done)" in bash and look at the CPU
  usage in top. After a fresh boot, the two subshells run with 100% CPU
  usage each, so each gets its own core to run on. When running this
  experiment after a suspend/resume cycle the two subshells run with 50%
  CPU usage each, so they're made to share a CPU core, although idle CPU
  cores are available.

  Steps to reproduce:
  * Boot system
  * log in as normal user
  * run the following command in a terminal window running bash: (while true; do true; done) & (while true; do true; done)
  * In a second terminal window run top and observe two bash processes at the top, each running with 100% CPU usage
    (each bash gets its own CPU core)
  * kill the two bash subshell processes
  * suspend to disk
  * wake up the system
  * Run the same command as above: (while true; do true; done) & (while true; do true; done)
  * In top the two bash processes run with 50% CPU usage
    (the two bash processes apparently share one CPU core, although idle cores are available)

  Expected result: load balancing should continue working after
  resuming. The two bash subshells should each run with 100% CPU usage.

  Actual result: load balancing is broken after resume. The two bash
  subshells have to share a CPU core even when idle CPU cores are
  available to balance the load.

  ProblemType: Bug
  DistroRelease: Ubuntu 10.10
  Package: linux-image-2.6.35-22-generic 2.6.35-22.34
  Regression: Yes
  Reproducible: Yes
  ProcVersionSignature: Ubuntu 2.6.35-22.34-generic 2.6.35.4
  Uname: Linux 2.6.35-22-generic x86_64
  NonfreeKernelModules: fglrx
  AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
  Architecture: amd64
  ArecordDevices:
   **** List of CAPTURE Hardware Devices ****
   card 0: Intel [HDA Intel], device 0: VT1828S Analog [VT1828S Analog]
     Subdevices: 2/2
     Subdevice #0: subdevice #0
     Subdevice #1: subdevice #1
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC0:  fkuehlin   1753 F.... pulseaudio
   /dev/snd/pcmC0D0p:   fkuehlin   1753 F...m pulseaudio
  CRDA: Error: [Errno 2] No such file or directory
  Card0.Amixer.info:
   Card hw:0 'Intel'/'HDA Intel at 0xfbaf8000 irq 52'
     Mixer name	: 'VIA VT1828S'
     Components	: 'HDA:11064441,104383d0,00100100'
     Controls      : 35
     Simple ctrls  : 20
  Card1.Amixer.info:
   Card hw:1 'Generic'/'HD-Audio Generic at 0xfbbfc000 irq 53'
     Mixer name	: 'ATI R6xx HDMI'
     Components	: 'HDA:1002aa01,00aa0100,00100200'
     Controls      : 4
     Simple ctrls  : 1
  Card1.Amixer.values:
   Simple mixer control 'IEC958',0
     Capabilities: pswitch pswitch-joined penum
     Playback channels: Mono
     Mono: Playback [on]
  Date: Fri Oct 15 14:56:46 2010
  HibernationDevice: RESUME=UUID=8f6cfcae-9123-48f0-a9c6-1e962e6b726e
  InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429)
  IwConfig:
   lo        no wireless extensions.
   
   eth0      no wireless extensions.
  MachineType: System manufacturer System Product Name
  ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.35-22-generic root=UUID=c9f4b289-89ae-42c0-ba57-13b1b26131da ro quiet splash
  ProcEnviron:
   PATH=(custom, user)
   LANG=en_CA.UTF-8
   SHELL=/bin/bash
  RelatedPackageVersions: linux-firmware 1.38
  RfKill:
   
  SourcePackage: linux
  WifiSyslog:
   Oct 15 14:55:59 Harpoon kernel: [17206.856773] ACPI Warning: Incorrect checksum in table [OEMB] - 0x03, should be 0xED (20100428/tbutils-314)
   Oct 15 14:55:59 Harpoon kernel: [17206.856958] ACPI Warning: Incorrect checksum in table [OEMB] - 0x03, should be 0xED (20100428/tbutils-314)
  dmi.bios.date: 03/25/2010
  dmi.bios.vendor: American Megatrends Inc.
  dmi.bios.version: 1408
  dmi.board.asset.tag: To Be Filled By O.E.M.
  dmi.board.name: P7P55D
  dmi.board.vendor: ASUSTeK Computer INC.
  dmi.board.version: Rev 1.xx
  dmi.chassis.asset.tag: Asset-1234567890
  dmi.chassis.type: 3
  dmi.chassis.vendor: Chassis Manufacture
  dmi.chassis.version: Chassis Version
  dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1408:bd03/25/2010:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnP7P55D:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
  dmi.product.name: System Product Name
  dmi.product.version: System Version
  dmi.sys.vendor: System manufacturer

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