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Tuned Replaces Power-profiles-daemon

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This is a rejected Change proposal for Fedora Linux.
This document represents a proposed Change that has been rejected or withdrawn as part of the Changes process. This page is preserved for historical record.

Summary

Tuned and power-profiles-daemon provide a similar function to set and tune the power status of a system. However, the power-profiles-daemon provides limited profiles to configure the power status of a system. In the meantime, tuned provides many power profiles for different kinds of use cases and technologies. 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 would like to replace power-profiles-daemon with tuned. As far as we know, tuned already provides power profiles for different use cases and power-profiles-daemon provides the basic power profile configuration, such platform_profiles, Intel p-state, and AMD p-state. Recently, tuned released the translation API layer called tuned-ppd which can translate the p-p-d API to tuned. The applications that use p-p-d API can access tuned without modifying the code. That gives all developers more time to convert the p-p-d API to tuned and reduce the impact on all desktop environments, such as GNOME, KDE...etc. For now, the Fedora user can immediately switch to tuned by installing tuned-ppd package without impacting the user experience. The API issue was resolved by tuned-ppd so now tuned can be used as a power setting service for Fedora.

Owner

Current status

Detailed Description

This work would like to replace power-profiles-daemon (p-p-d) 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.

As far as we know, 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. If the power-profiles-daemon can be replaced with tuned. The users would have a wide range of profiles to fine-tune the system.

Tuned released a new translation API service called tuned-ppd [1]. tuned-ppd can translate the p-p-d API to tuned API so the application can talk with tuned without modifying the codes. Moreover, the GUI settings, such as gnome-control-center can configure tuned profile 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 wnat to use a customized profile, they can edit the config file and map the custom profile to the basic three p-p-d profile names. In this way, gnome-control-center can keep the original design and new GUI tools to set the customized profile becomes unnecessary.

The work expects the tuned replace the power-profiles-daemons to offer a wide range of power profiles to the fedora users. tuned-ppd resolved the API translation issue so the application can access tuned service through p-p-d API without converting to tuned API. Moreover, tuned allows the three profiles to be overridden with custom power profiles if the user wants to use custom profiles for the specific use cases. It also benefits GNOME applications that can keep the original design and a new GUI tool for custom profile is unnecessary. Therefore, now 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 by 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.

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:
  • Other developers:
  • Policies and guidelines: N/A (not needed for this Change)
  • Trademark approval: N/A (not needed for this Change)
  • Alignment with Community Initiatives:

Upgrade/compatibility impact

Both the tuned and the power panel need to be modified to integrate both.

Tuned doesn't support all the same features as power-profiles-daemon. Power-profiles-daemon reacts to AC charger plugin or plug out events and changes AMD display settings. This will cause increased power consumption for users.

How To Test

User Experience

1. The workstation user can set the power profile through gnome-control-center. Moreover, an advanced power profile dialog will be shown if the users would like to finetune the system.

2. The server users switch the profile through the commandline or GNOME desktop if it is installed.

Dependencies

1. tuned is written by Python so it depends on python packages and its 40 packages.

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 ppd APIs otherwise the original power-profile-daemon can be used.

Documentation

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

N/A (not a System Wide Change)

Release Notes