ondemand CPU Scaling does not work when AC adapter is plugged in

Bug #555315 reported by Dana Leonard
38
This bug affects 8 people
Affects Status Importance Assigned to Milestone
gnome-applets (Ubuntu)
Expired
Low
Unassigned

Bug Description

Binary package hint: gnome-applets

Ubuntu 11.04
Ubuntu 9.10
gnome-applets:
  Installed: 2.28.0-0ubuntu2
  Candidate: 2.28.0-0ubuntu2

When unplugged, the tool from the panel works just fine and cpufreq-info shows the range of frequencies available as 800-2270. When the AC adapter is plugged in, this range is bounded to 800-800. Performance using Flash or any other semi-demanding task is terrible.

cpufreq-info output when plugged into AC power:
cpufrequtils 005: cpufreq-info (C) Dominik Brodowski 2004-2006
Report errors and bugs to <email address hidden>, please.
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which need to switch frequency at the same time: 0
  hardware limits: 800 MHz - 2.27 GHz
  available frequency steps: 2.27 GHz, 2.27 GHz, 1.60 GHz, 800 MHz
  available cpufreq governors: conservative, ondemand, userspace, powersave, performance
  current policy: frequency should be within 800 MHz and 800 MHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 800 MHz.
  cpufreq stats: 2.27 GHz:0.00%, 2.27 GHz:0.00%, 1.60 GHz:0.00%, 800 MHz:0.00% (6)
analyzing CPU 1:
  driver: acpi-cpufreq
  CPUs which need to switch frequency at the same time: 1
  hardware limits: 800 MHz - 2.27 GHz
  available frequency steps: 2.27 GHz, 2.27 GHz, 1.60 GHz, 800 MHz
  available cpufreq governors: conservative, ondemand, userspace, powersave, performance
  current policy: frequency should be within 800 MHz and 800 MHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 800 MHz.
  cpufreq stats: 2.27 GHz:0.00%, 2.27 GHz:0.00%, 1.60 GHz:0.00%, 800 MHz:0.00% (4)

ProblemType: Bug
Architecture: i386
Date: Sun Apr 4 15:44:04 2010
DistroRelease: Ubuntu 9.10
ExecutablePath: /usr/bin/yelp
NonfreeKernelModules: nvidia
Package: yelp 2.28.0-0ubuntu2
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-20.58-generic
SourcePackage: yelp
Uname: Linux 2.6.31-20-generic i686
XsessionErrors:
 (gnome-settings-daemon:2194): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (gnome-settings-daemon:2194): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (polkit-gnome-authentication-agent-1:2286): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
 (nautilus:2280): Eel-CRITICAL **: eel_preferences_get_boolean: assertion `preferences_is_initialized ()' failed
 (firefox:2594): GLib-WARNING **: g_set_prgname() called multiple times

Revision history for this message
Dana Leonard (dleonar) wrote :
summary: - CPU Scaling does not work when AC adapter is plugged in
+ ondemand CPU Scaling does not work when AC adapter is plugged in
Revision history for this message
Pedro Villavicencio (pedro) wrote :

Thanks for the report, it has been some time without any response or feedback in this bug report and we are wondering if this is still an issue for you with the latest release of Ubuntu the Natty Narwhal, May you please test with that version and comment back if you're still having or not the issue? Please have a look at http://www.ubuntu.com/download to know how to install that version.Thanks in advance and sorry for the late response.

Changed in gnome-applets (Ubuntu):
importance: Undecided → Low
status: New → Incomplete
Revision history for this message
Joel Hegberg (joelhegberg) wrote :
Download full text (3.4 KiB)

This bug also affects me.
When on battery, cpu frequency scales properly on-demand 1.6 to 2.8 GHz. (current policy shows range of 1.6 to 2.8)
When AC adapter is plugged in, cpu frequency is locked at 1.6 Ghz. (current policy shows range of 1.6 to 1.6)

-Computer-
Processor : 2x Intel(R) Core(TM)2 Duo CPU T9600 @ 2.80GHz
Memory : 4111MB (543MB used)
Operating System : Ubuntu 11.04

cpufrequtils 007: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to <email address hidden>, please.
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0 1
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.0 us.
  hardware limits: 1.60 GHz - 2.80 GHz
  available frequency steps: 2.80 GHz, 2.80 GHz, 2.13 GHz, 1.60 GHz
  available cpufreq governors: conservative, ondemand, userspace, powersave, performance
  current policy: frequency should be within 1.60 GHz and 1.60 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 1.60 GHz.
  cpufreq stats: 2.80 GHz:5.64%, 2.80 GHz:0.28%, 2.13 GHz:0.35%, 1.60 GHz:93.73% (4292)
analyzing CPU 1:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0 1
  CPUs which need to have their frequency coordinated by software: 1
  maximum transition latency: 10.0 us.
  hardware limits: 1.60 GHz - 2.80 GHz
  available frequency steps: 2.80 GHz, 2.80 GHz, 2.13 GHz, 1.60 GHz
  available cpufreq governors: conservative, ondemand, userspace, powersave, performance
  current policy: frequency should be within 1.60 GHz and 1.60 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 1.60 GHz.
  cpufreq stats: 2.80 GHz:6.37%, 2.80 GHz:0.09%, 2.13 GHz:0.11%, 1.60 GHz:93.44% (2654)
----
cpufrequtils 007: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to <email address hidden>, please.
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0 1
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 10.0 us.
  hardware limits: 1.60 GHz - 2.80 GHz
  available frequency steps: 2.80 GHz, 2.80 GHz, 2.13 GHz, 1.60 GHz
  available cpufreq governors: conservative, ondemand, userspace, powersave, performance
  current policy: frequency should be within 1.60 GHz and 2.80 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 1.60 GHz.
  cpufreq stats: 2.80 GHz:5.58%, 2.80 GHz:0.29%, 2.13 GHz:0.35%, 1.60 GHz:93.78% (4371)
analyzing CPU 1:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0 1
  CPUs which need to have their frequency coordinated by software: 1
  maximum transition latency: 10.0 us.
  hardware limits: 1.60 GHz - 2.80 GHz
  available frequency steps: 2.80 GHz, 2.80 GHz, 2.13 GHz, 1.60 GHz
  available cpufreq governors: conservative, ondemand, userspace, powersave, performance
  current policy: frequency should be within 1.60 GHz and 2....

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Revision history for this message
Joel Hegberg (joelhegberg) wrote :

Additional information:
When I set the governor to "performance", then when the laptop is on battery power the CPU frequency is ramped up from 1.60GHz to the full 2.80GHz.
When the A/C power adapter is plugged in and the governor is set to "performance", the CPU frequency remains at 1.60GHz and never increases.

Changed in gnome-applets (Ubuntu):
status: Incomplete → Confirmed
description: updated
Revision history for this message
Marcos (marcoscdlf) wrote :

I have this issue on a new Thinkpad X220 only when i am on AC power WITHOUT the battery. I've found that this happens due the 65W AC adaptor does not supply enough power to handle peak power draws from the CPU/disk/GPU on the later ThinkPads and probably other laptops and automatically downclocks CPU to the lowest frequency.
The explanation and possible solution in this page : <a href = "http://www.thinkwiki.org/wiki/Problem_with_CPU_frequency_scaling">http://www.thinkwiki.org/wiki/Problem_with_CPU_frequency_scaling</a>

Revision history for this message
Thomas Hood (jdthood) wrote :

Regarding ThinkPad throttling the CPU when powered by the 65 W AC adapter and no battery, see
http://forums.lenovo.com/t5/X-Series-Tablet-ThinkPad-Laptops/X61-Your-power-adapter-may-be-cheating-you/td-p/17870

Alan Pater (alan-pater)
Changed in gnome-applets (Ubuntu):
status: Confirmed → Incomplete
Revision history for this message
Launchpad Janitor (janitor) wrote :

[Expired for gnome-applets (Ubuntu) because there has been no activity for 60 days.]

Changed in gnome-applets (Ubuntu):
status: Incomplete → Expired
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