Comment 138 for bug 524281

Also running a self-compiled 2.6.35-rc3, it is amazing on my Atom netbook, but
Load Balancing ticks are still skyrocketing on my Athlon II dual core. Do I need
to enable any config option I have missed? (Used the mainline kernel PPA on
the Atom, compiled myself for the Athlon II to include a custom fix.) Maybe I
need to retry with the Maverick config.

2010/9/7 Sidnei da Silva <email address hidden>:
> @Andy:
>
> I'm running a fully-up-to-date Maverick, and still getting tons of
> wakeups from load balancing ticks. It's consistently the top one, at:
>
>  28.1% (200.1)   [kernel scheduler] Load balancing tick
>
> That's with:
>
>  Linux sidnei-laptop 2.6.35-20-generic #29-Ubuntu SMP Fri Sep 3
> 14:55:28 UTC 2010 x86_64 GNU/Linux
>
> --
> Tens of wakes per second in "[kernel scheduler] Load balancing tick" on Core 2 Duo even with only 1 core enabled
> https://bugs.launchpad.net/bugs/524281
> You received this bug notification because you are a direct subscriber
> of the bug.
>
> Status in “linux” package in Ubuntu: Triaged
> Status in Arch Linux: New
> Status in “linux-2.6” package in Debian: Incomplete
>
> Bug description:
> powertop reports many wakes per second (quantity depending on system)  in "[kernel scheduler] Load balancing tick" task, rising with little load, on many kinds of multi-core (?) systems (original report was on a Core 2 Duo processor (T6500) with a single core enabled (multicore disabled in BIOS)).
>
> Cause of the problem:
> With kernel 2.6.32, there came a patch to the scheduler that introduced this problem (that was backported to some other versions as well). Even though this problem occurred first in Lucid, it is NOT specific to Lucid or Ubuntu at all (Debian bug report at http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=521944, reproducable in Arch Linux as well). Work is ongoing to get things straight in kernel, but it will take a long time until this reaches Ubuntu (see http://lkml.org/lkml/2010/7/6/172).
>
> Workarounds that DO NOT work (may improve situation but not solve it):
> - maxcpus=1
> - noapic
> - nosmp
> - nolapic
> - use mainline kernel
>
> Workarounds that DO (probably) work:
> - tip version of kernel (git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git, from http://lkml.org/lkml/2010/7/8/75)
> - use maverick's kernel with applied patches (https://launchpad.net/~brian-rogers/+archive/power, from comment #80)
>
> ProblemType: Bug
> AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.21.
> Architecture: i386
> ArecordDevices:
>  **** List of CAPTURE Hardware Devices ****
>  card 0: Intel [HDA Intel], device 0: ALC269 Analog [ALC269 Analog]
>    Subdevices: 1/1
>    Subdevice #0: subdevice #0
> AudioDevicesInUse:
>  USER        PID ACCESS COMMAND
>  /dev/snd/controlC0:  etrusco    1606 F.... pulseaudio
>                       etrusco   15151 F.... foobar2000.exe
> CRDA: Error: [Errno 2] No such file or directory
> Card0.Amixer.info:
>  Card hw:0 'Intel'/'HDA Intel at 0xfddf8000 irq 22'
>    Mixer name   : 'Realtek ALC269'
>    Components   : 'HDA:10ec0269,1b0a4009,00100004 HDA:11c11040,1b0a4007,00100200'
>    Controls      : 19
>    Simple ctrls  : 11
> Card1.Amixer.info:
>  Card hw:1 'HDMI'/'HDA ATI HDMI at 0xfebec000 irq 17'
>    Mixer name   : 'ATI R6xx HDMI'
>    Components   : 'HDA:1002aa01,00aa0100,00100100'
>    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 Feb 19 05:25:42 2010
> DistroRelease: Ubuntu 10.04
> EcryptfsInUse: Yes
> MachineType: Philco PHN10XXX.
> Package: linux-image-2.6.32-13-generic 2.6.32-13.18
> ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-13-generic root=UUID=d482e94f-9370-4ad2-9536-986541003db5 ro acpi.power_nocheck=1 acpi_osi=linux radeon.blacklist=yes
> ProcEnviron:
>  LANG=en_US.UTF-8
>  SHELL=/bin/bash
> ProcVersionSignature: Ubuntu 2.6.32-13.18-generic
> Regression: No
> RelatedPackageVersions: linux-firmware 1.29
> Reproducible: Yes
> RfKill:
>  0: phy0: Wireless LAN
>   Soft blocked: no
>   Hard blocked: no
> SourcePackage: linux
> TestedUpstream: No
> Uname: Linux 2.6.32-13-generic i686
> dmi.bios.date: 06/01/2009
> dmi.bios.vendor: American Megatrends Inc.
> dmi.bios.version: 1.01
> dmi.board.asset.tag: To Be Filled By O.E.M.
> dmi.board.vendor: PEGATRON CORP.
> dmi.board.version: To be filled by O.E.M.
> dmi.chassis.asset.tag: To Be Filled By O.E.M.
> dmi.chassis.type: 10
> dmi.chassis.vendor: PEGATRON CORP.
> dmi.chassis.version: To Be Filled By O.E.M.
> dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1.01:bd06/01/2009:svnPhilco:pnPHN10XXX.:pvr1.01:rvnPEGATRONCORP.:rn:rvrTobefilledbyO.E.M.:cvnPEGATRONCORP.:ct10:cvrToBeFilledByO.E.M.:
> dmi.product.name: PHN10XXX.
> dmi.product.version: 1.01
> dmi.sys.vendor: Philco
>
>
>
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