Changes/Power Profiles Daemon

Use power-profiles-daemon on Workstation

Summary

We will install power-profiles-daemon in Fedora Workstation and enable it by default. power-profiles-daemon allows the user to choose between optimizing for system performance or battery life.

Owner

• Name: Bastien Nocera
• Email: bnocera@redhat.com
• Name: Michael Catanzaro
• Email: mcatanzaro@redhat.com
• Name: Neal Gompa
• Email: ngompa13@gmail.com

Current status

• Targeted release: Fedora Linux 35
• Last updated: 2021-07-23
• FESCo issue: <will be assigned by the Wrangler>
• Tracker bug: <will be assigned by the Wrangler>
• Release notes tracker: <will be assigned by the Wrangler>

Detailed Description

From the upstream README:

power-profiles-daemon offers to modify system behaviour based upon user-selected power profiles. There are 3 different power profiles, a "balanced" default mode, a "power-saver" mode, as well as a "performance" mode. The first 2 of those are available on every system. The "performance" mode is only available on select systems and is implemented by different "drivers" based on the system or systems it targets.

In addition to those 2 or 3 modes (depending on the system), "actions" can be hooked up to change the behaviour of a particular device. For example, this can be used to disable the fast-charging for some USB devices when in power-saver mode.

GNOME's Settings and shell both include interfaces to select the current mode, but they are also expected to adjust the behaviour of the desktop depending on the mode, such as turning the screen off after inaction more aggressively when in power-saver mode.

Benefit to Fedora

Shipping power-profiles-daemon enables GNOME to display and offer users the ability to adjust configuration related to power management similar to other operating systems, which can improve the quality of the on-battery experience (with respect to longevity of operating on battery power).

Scope

• Proposal owners: Add Recommends: power-profiles-daemon to gnome-control-center package. Add systemd preset to fedora-release.
• Other developers: N/A (not needed for this Change)
• Release engineering: N/A (not needed for this Change)
• Policies and guidelines: N/A (not needed for this Change)
• Trademark approval: N/A (not needed for this Change)
• Alignment with Objectives: Nope.

Upgrade/compatibility impact

power-profiles-daemon will be installed on upgrade to Fedora 35 if gnome-control-center is installed. Since the default power profile is the balanced mode, users should not notice performance changes (sans bugs), but the option to manually select either performance or power saving mode will now be present.

How To Test

Visit the Power settings panel in gnome-control-center and switch between performance, balanced, and power save mode. Look for unexpected behavior changes over long periods of time. For example, selecting Performance mode should improve CPU performance but reduce battery life. Selecting power save mode should reduce performance but increase battery life. Selecting balanced mode should not change anything.

The selected power save mode should persist across system reboots.

User Experience

GNOME Control Center will show a new section in the Power page giving users the option to select power modes:

• Balanced (the default)
• Performance (to maximize performance)
• Power saver (to maximize battery life)

User selection of these profiles will set various tunables to meet the needs as described in the profiles.

Dependencies

gnome-control-center depends on power-profiles-daemon to offer power saving options. If not installed, these options will not be present in the power panel.

Contingency Plan

• Contingency mechanism: we can easily remove the Recommends: in gnome-control-center or the preset in fedora-release if necessary.
• Contingency deadline: N/A (not a System Wide Change)
• Blocks release? No

Documentation

The only documentation is the upstream project README: https://gitlab.freedesktop.org/hadess/power-profiles-daemon/-/blob/main/README.md

Release Notes

Fedora Workstation now ships with power-profiles-daemon installed and enabled.