Difference between revisions of "CPU Freq"
From eLinux.org
m (Bot (Edward's framework)) |
(fix up bullets) |
||
| Line 2: | Line 2: | ||
From the [http://www.advogato.org/proj/CPUFreq/ CPUFreq home page]: | From the [http://www.advogato.org/proj/CPUFreq/ CPUFreq home page]: | ||
| + | |||
Clock scaling allows you to change the clock speed of the running CPU on the fly. | Clock scaling allows you to change the clock speed of the running CPU on the fly. | ||
This is a nice method to save battery power, because the lower the clock speed, the less | This is a nice method to save battery power, because the lower the clock speed, the less | ||
| Line 11: | Line 12: | ||
== Resources == | == Resources == | ||
| − | + | * [[CPU Freq]] home page: http://www.advogato.org/proj/CPUFreq/ (it looks a little out-of-date) | |
| − | + | * Source Forge project for cpufreqd: http://sourceforge.net/projects/cpufreqd/ | |
| − | + | * LWN.net article pointing to Documentation post for 2.5.32 kernel: http://lwn.net/Articles/8642/ | |
| − | + | * Documentation is available in the source tree | |
| − | + | ** <celinux>/Documentation/cpufreq | |
| − | + | ** <kernel.org 2.6 linux>/Documentation/cpu-freq/* | |
== Code Status == | == Code Status == | ||
| − | + | * patches are available at: http://www.codemonkey.org.uk/projects/cpufreq/ | |
The code in the CELF tree doesn't bear much resemblance to the current patches. | The code in the CELF tree doesn't bear much resemblance to the current patches. | ||
Note that this whole system appears to be a backport of this feature from the | Note that this whole system appears to be a backport of this feature from the | ||
2.5/6 kernel version. | 2.5/6 kernel version. | ||
Revision as of 04:17, 30 November 2007
Information about CPU Frequency Scaling.
From the CPUFreq home page:
Clock scaling allows you to change the clock speed of the running CPU on the fly. This is a nice method to save battery power, because the lower the clock speed, the less power the CPU consumes. CPU Freq is a generic framework to make architecture implementation specifics transparent to a user. Currently, CPU Freq supports various ARM CPUs (Integrator, SA1100, SA1110), various x86's (AMD Power NOW, VIA Cyrix Longhaul), and various Super H CPUs (SH-4 7750/7751, SH-3, and so forth). This project also incorporates some work at reverse engineering support for Intel Speedstep technology.
Resources
- CPU Freq home page: http://www.advogato.org/proj/CPUFreq/ (it looks a little out-of-date)
- Source Forge project for cpufreqd: http://sourceforge.net/projects/cpufreqd/
- LWN.net article pointing to Documentation post for 2.5.32 kernel: http://lwn.net/Articles/8642/
- Documentation is available in the source tree
- <celinux>/Documentation/cpufreq
- <kernel.org 2.6 linux>/Documentation/cpu-freq/*
Code Status
- patches are available at: http://www.codemonkey.org.uk/projects/cpufreq/
The code in the CELF tree doesn't bear much resemblance to the current patches. Note that this whole system appears to be a backport of this feature from the 2.5/6 kernel version.
