F40 Change Proposal: Tuned Replaces Power-profiles-daemon (Self-Contained)

[Aoife Moloney]

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.

Wiki: https://fedoraproject.org/wiki/Changes/TunedReplacesPower-profiles-daemon

= Tuned Replaces Power-profiles-daemon =

== 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. We expected that the user can set those profile, tuned
provided through gnome-control-panel. To minimize the information to
the user, the power panel would provide a simple and advanced mode to
show the power profiles. If the users want to finetune the system,
they can switch to the advanced mode themselves. The impact scope will
be on the tuned and the power panel since tuned should provide the
basic power setting and API as power-profiles-daemon and the power
panel should be able to show the power profiles that tuned provides.

== Owner ==

* Name: [[User:smallorange| Kate Hsuan]]
* Email:

== Detailed Description ==

This work would like to 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.

As far as we know, tuned provide many kinds of advanced and basic
profile 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 finetune
their system. If the power-profiles-daemon can be replaced with tuned.
The users would have a wide range of profiles to finetune the system.

If the tuned would be the major power profile management tool, the
major impact scope will be on gnome-control-center power panel and
tuned itself. Tuned should also provide the new Dbus API to provide
the access point to applications. The other is the
gnome-control-center power panel. An "Advanced profile" dialog should
be made to show advanced profiles to the user. Moreover, the server
users need to get used to another command to switch the profiles.

The work expects the tuned replaces the power-profiles-daemons to
offer a wide range of power profiles to the fedora users. To integrate
them, gnome-control-center power panel needs to add an Advanced
profile dialog to use those advanced features. Tuned also needs to
integrate the original API to ensure compatibility with legacy
applications and provide the basic configuration if the user would
stay in basic profiles.

== Feedback ==
'''From fedora-devel'''

https://lists.fedoraproject.org/archives/list/[e-mail]/...

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:

* Release engineering: [https://pagure.io/releng/issues #Releng issue number]

* 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.

== 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)
* Contingency deadline: N/A (not a System Wide Change)
* Blocks release? N/A (not a System Wide Change)

== Documentation ==

N/A (not a System Wide Change)

== Release Notes ==