tools/power/cpupower/README

File Facts

System

Linux kernel

Corpus path

tools/power/cpupower/README

Extension

[no extension]

Size

7401 bytes

Lines

216

Domain

Support Tooling And Documentation

Bucket

tools

Inferred role

Support Tooling And Documentation: tools

Status

atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

• Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

• No C-style include directives detected by the generator.

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

The cpupower package consists of the following elements:

requirements
------------

On x86 pciutils is needed at runtime (-lpci).
For compilation pciutils-devel (pci/pci.h) and a gcc version
providing cpuid.h is needed.
For both it's not explicitly checked for (yet).


libcpupower
----------

"libcpupower" is a library which offers a unified access method for userspace
tools and programs to the cpufreq core and drivers in the Linux kernel. This
allows for code reduction in userspace tools, a clean implementation of
the interaction to the cpufreq core, and support for both the sysfs and proc
interfaces [depending on configuration, see below].


compilation and installation
----------------------------

There are 2 output directories - one for the build output and another for
the installation of the build results, that is the utility, library,
man pages, etc...

default directory
-----------------

In the case of default directory, build and install process requires no
additional parameters:

build
-----

$ make

The output directory for the 'make' command is the current directory and
its subdirs in the kernel tree:
tools/power/cpupower

install
-------

$ sudo make install

'make install' command puts targets to default system dirs:

-----------------------------------------------------------------------
| Installing file        |               System dir                   |
-----------------------------------------------------------------------
| libcpupower            | /usr/lib                                   |
-----------------------------------------------------------------------
| cpupower               | /usr/bin                                   |
-----------------------------------------------------------------------
| cpufreq-bench_plot.sh  | /usr/bin                                   |
-----------------------------------------------------------------------
| man pages              | /usr/man                                   |
-----------------------------------------------------------------------
| systemd service        | /usr/lib/systemd/system                    |
-----------------------------------------------------------------------
| systemd support script | /usr/libexec                               |
-----------------------------------------------------------------------

To put it in other words it makes build results available system-wide,
enabling any user to simply start using it without any additional steps

custom directory

Annotation

• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: atlas-only.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.