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Make Tuned the Default Power Profile Management Daemon

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This is a proposed Change for Fedora Linux.
This document represents a proposed Change. As part of the Changes process, proposals are publicly announced in order to receive community feedback. This proposal will only be implemented if approved by the Fedora Engineering Steering Committee.

Summary

This Change makes ‘tuned’ the default power profile management daemon in Fedora Workstation, KDE Plasma, and Budgie instead of power-profiles-daemon.

  • tuned-ppd provides a drop-in replacement for power-profiles-daemon, which allows it to be used with current desktops
  • power users can customize the desktop-exposed power profiles by editing /etc/tuned/ppd.conf

Owner

Current status

Detailed Description

Tuned and power-profiles-daemon provide a similar function to set and tune the power status of a system. Both of them have similar features, if they can be integrated into one, it allows the Fedora user to have more options for power settings of their system and benefits the users. In this proposal, we set up tuned to the default power profile management daemon for the GNOME in Fedora Workstation and the KDE Plasma Spin. Tuned already provides power profiles for different use cases. Recently, tuned released the translation API layer called tuned-ppd which can translate the power-profiles-daemon API to tuned. The applications that use power-profiles-daemon API can access tuned without modifying the code. For now, the Fedora user can immediately switch to tuned by installing the tuned-ppd package without impacting the user experience. Therefore, tuned can be the default power profile management daemon for Fedora.

This work would replace power-profiles-daemon with tuned. Since tuned already provides a wide range of power profiles for different purposes, this allows the user to have more options for configuring the system power profile. Tuned provides many kinds of advanced and basic profiles for different purposes. Power-profiles-daemon provides the basic power profiles and the profiles can be set to the system through platform_profiles, Intel p-state and AMD p-state. That is simple and clever. However, if the users want to ask for an advanced profile, they need to install another power utility, such as tuned to fine-tune their system. With tuned as the default power profile management daemon, users have a wider range of profiles to fine-tune the system.

Tuned released a new translation API service called tuned-ppd [1]. tuned-ppd can translate the power-profiles-daemon API to the tuned API so applications can talk with tuned without modification. Moreover, the GUI settings, such as gnome-control-center can configure tuned profiles through tuned-ppd. tuned-ppd also allows the user to override the basic three power profiles, including power-saver, balanced, and performance through the config file /etc/tuned/ppd.conf [2]. If the user wants to use a customized profile, they can edit the config file and map the custom profile to the basic three power-profiles-daemon profile names. In this way, gnome-control-center can keep the original design to configure the customized profile.

The work expects tuned to replace the power-profiles-daemons to offer a wider range of power profiles to Fedora users. tuned-ppd resolved the API translation issue so the application can access tuned service through power-profiles-daemon API without converting to the tuned API. Moreover, the three basic profiles can be overridden when the user needs it for their use case. It also benefits GNOME applications that can keep the original design and designing a new GUI tool for custom profiles is unnecessary. Therefore, tuned can be the default power setting service for Fedora.

Feedback

From fedora-devel

https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/thread/B3UJKFOCRAY3BEEPTHVPW4RY5GFBZWHU/#B3UJKFOCRAY3BEEPTHVPW4RY5GFBZWHU 1. The dependency concern. Since tuned is written in Python, that causes a dependency impact on Fedora installation. 2. The power-profiles-daemon API should be ported to tuned to provide the function to the application that uses power-profiles-daemon API, such as gnome-shell and gnome-control-center.

From the hardware vendor

Moreover, we discuss it with vendors through the mail. 1. Since tuned covers several kinds of system tuning schemes that allow the vendor to implement their power profile for different devices or workloads. For power-profile-daemon, it only has three profiles to set and every detail setting should be done through the firmware level. If tuned can replace power-profiles-daemon, they can imagine they can develop the profile in a much more flexible manner.

The previous discussions

https://discussion.fedoraproject.org/t/f40-change-proposal-tuned-replaces-power-profiles-daemon-self-contained/94995

Benefit to Fedora

  1. Benefits the user. The user would have more options to tune their system.
  2. Benefits the maintainer. Integrate similar software into one software to reduce the maintenance effort.

Scope

  • Proposal owners:
    • for GNOME: update gnome-control-center weak dependency on power-profile-daemon to tuned-ppd
    • for KDE: update powerdevil weak dependency on power-profile-daemon to tuned-ppd
    • for Budgie: update budgie-control-center weak dependency on power-profile-daemon to tuned-ppd
  • Other developers:
  • Policies and guidelines: N/A (not needed for this Change)
  • Trademark approval: N/A (not needed for this Change)
  • Alignment with the Fedora Strategy:

Upgrade/compatibility impact

Since tuned-ppd provides the ppd APIs and features, there is no impact on other applications.

Early Testing (Optional)

Do you require 'QA Blueprint' support? Y/N

How To Test

  1. Remove power-profiles-daemon.
    $ sudo dnf remove power-profiles-daemon
  2. Install tuned and tuned-ppd through the following command
    $ sudo dnf install tuned
    $ sudo dnf install tuned-ppd
  3. Run gnome-control-center and switch to the power panel and then select one of the three power profiles. Click the top-right corner of the screen and you can see the “Power Mode” shows the profile name that you selected previously.
  4. Run the following command to show the active profile. Since tuned-adm shows the tuned profile name, the profile name mapping can be found in /etc/tuned/ppd.conf.
    $ tuned-adm active

User Experience

  1. The workstation user can set the power profile through the gnome-control-center.
  2. The server users switch the profile through the tuned command line.

Dependencies

budgie-control-center, gnome-control-center, and powerdevil can talk to tuned-ppd via dbus.

Contingency Plan

  • Contingency mechanism: (What to do? Who will do it?) N/A (not a System Wide Change)

Use the original power-profiles-daemon

  • Contingency deadline: N/A (not a System Wide Change)

Before F41 beta freeze.

  • Blocks release? N/A (not a System Wide Change), Yes/No

No, tuned-ppd provides all the power-profiles-daemon APIs otherwise the original power-profile-daemon can be used when the plan blocks the release.

Documentation

I have talked with tuned about this information.
https://github.com/redhat-performance/tuned/issues/559

Release Notes