ONDEMAND governer always uses 100%

Bug #684712 reported by kiu
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Invalid
Undecided
Unassigned

Bug Description

I configured CPU0 and CPU1 to use ONDEMAND.

htop shows me that CPU0 and CPU1 have both around 3% usage (while being idle in gnome), but still

- CPU0 always stays at 100% (2.13Ghz)
- CPU1 stays at 37% (800Mhz)
- If the CPU1 usage goes over 5%, it is shortly boosted to 100% (2.13Ghz)

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: linux-image 2.6.35.23.25
Regression: Yes
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.35-23.41-generic 2.6.35.7
Uname: Linux 2.6.35-23-generic x86_64
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: CONEXANT Analog [CONEXANT Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: kiu 2254 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xf2620000 irq 47'
   Mixer name : 'Conexant CX20561 (Hermosa)'
   Components : 'HDA:14f15051,17aa20ff,00100000'
   Controls : 14
   Simple ctrls : 7
Card29.Amixer.info:
 Card hw:29 'ThinkPadEC'/'ThinkPad Console Audio Control at EC reg 0x30, fw 7XHT22WW-1.04'
   Mixer name : 'ThinkPad EC 7XHT22WW-1.04'
   Components : ''
   Controls : 1
   Simple ctrls : 1
Card29.Amixer.values:
 Simple mixer control 'Console',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Date: Fri Dec 3 14:09:38 2010
HibernationDevice: RESUME=UUID=3c19c229-8c24-4669-9b7a-291cea5d834f
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100427.1)
MachineType: LENOVO 746988G
ProcCmdLine: BOOT_IMAGE=/vmlinuz-2.6.35-23-generic root=/dev/mapper/hostname-root ro quiet splash nolapci_timer clocksource=jiffies
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.utf8
 SHELL=/bin/bash
RelatedPackageVersions: linux-firmware 1.38
SourcePackage: linux
dmi.bios.date: 09/17/2009
dmi.bios.vendor: LENOVO
dmi.bios.version: 6DET60WW (3.10 )
dmi.board.name: 746988G
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:bvr6DET60WW(3.10):bd09/17/2009:svnLENOVO:pn746988G:pvrThinkPadX200s:rvnLENOVO:rn746988G:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 746988G
dmi.product.version: ThinkPad X200s
dmi.sys.vendor: LENOVO

Revision history for this message
kiu (kiu) wrote :
tags: added: kernel-series-unknown
Revision history for this message
kiu (kiu) wrote :

At some point ubuntu added "clocksource=jiffies" to my grub. This leads to CPUs in 100% polling state (found by powertop), which will let the ondemand governor use max cpu speed all the time.

Removing the clocksource entry resolved the issue.

Brad Figg (brad-figg)
Changed in linux (Ubuntu):
status: New → Confirmed
Revision history for this message
penalvch (penalvch) wrote :

kiu, this bug report is being closed due to your last comment regarding this being fixed with a configuration change. For future reference you can manage the status of your own bugs by clicking on the current status in the yellow line and then choosing a new status in the revealed drop down box. You can learn more about bug statuses at https://wiki.ubuntu.com/Bugs/Status. Thank you again for taking the time to report this bug and helping to make Ubuntu better. Please submit any future bugs you may find.

Changed in linux (Ubuntu):
status: Confirmed → Invalid
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