power-profiles-daemon package conflicts with TLP

[mhadidg]

Describe the bug

After I upgraded to Ubuntu 21.04. I noticed that tlp.service was not activated on system startup. It turns out that the service unit power-profiles-daemon.service of the new power-profiles-daemon package is the problem. It's declaring a conflict with tlp.service causing tlp.service to be effectively disabled.

Disabling power-profiles-daemon.service or removing power-profiles-daemon package resolves the issue for me.

This package is installed by default in Ubuntu 21.04+ and some other distributions as well.

/lib/systemd/system/power-profiles-daemon.service (notice the Conflicts directive)

[Unit]
Description=Power Profiles daemon
Conflicts=tuned.service tlp.service auto-cpufreq.service
Before=multi-user.target display-manager.target

...

Expected behavior

• The documentation may include a note under Installation > Ubuntu and FAQ > Installation sections explaining that a user must either disable power-profiles-daemon.service or remove power-profiles-daemon package for TLP to work properly; or
• TLP service unit may include Conflicts=power-profiles-daemon.service directive. This will resolve the issue in the current setup of both services, as tlp.service is activated before power-profiles-daemon.service.
• Optionally, configure TLP service unit with Before=power-profiles-daemon.service to make sure that tlp.service activation will always take precedence over power-profiles-daemon.service.

To Reproduce

1. Install power-profiles-daemon package.
2. Reboot.
3. Inspect the runtime status of tlp.service unit.

[linrunner]

Hi, thanks for the notification and your suggestions.

Would you please also open a Ubuntu bug about this? Canonical's oem team will be interested. They use TLP in hardware enablement for vendor specific power saving settings (afaik Dell and maybe others) and made TLP be included in the main repository some time ago.

In the meantime, I will consider which of your suggestions I consider best for "peaceful coexistence".

[linrunner]

Btw: disabling tlp.service does not completely disable TLP. Only the application of settings at boot is omitted (unfortunately also affects the charge thresholds). Next time the power source changes TLP's settings will take effect.

See

• https://linrunner.de/tlp/introduction.html#how-it-works
• https://linrunner.de/tlp/developers/architecture.html

[mhadidg]

An issue (bug #1934944) has been reported to Ubuntu TLP package maintainer.

[linrunner]

TLP service unit may include Conflicts=power-profiles-daemon.service directive.

Finally took the time to setup up a 21.04 system and can confirm this works as expected.

This will resolve the issue in the current setup of both services, as tlp.service is activated before power-profiles-daemon.service.

But I wonder why it works. tlp.service is (by design) started very late in the boot process, whereas power-profiles-daemon has no such dependencies.

tlp.service

[Unit]
Description=TLP system startup/shutdown
Conflicts=power-profiles-daemon.service
After=multi-user.target NetworkManager.service
Before=shutdown.target

power-profiles-daemon.service

[Unit]
Description=Power Profiles daemon
Conflicts=tuned.service tlp.service auto-cpufreq.service
Before=multi-user.target display-manager.target

[linrunner]

CORRECTION: actually it worked only once. For whatever reason.

Neither Conflicts=power-profiles-daemon.service nor an additional Before=power-profiles-daemon.service start tlp.service reliably.

[alex-tu-cc]

Hi @linrunner,
Thanks for reminder of this conflict.
The conflict was introduced from new gnome version and indeed will impact users who are counting on TLP for power saving.

Excuse me, but did you discuss the topic of how to keep the existed power saving experience offered by TLP on power-profiles-daemon with the power-profiles-daemon maintainer?

I am wondering if the maintainer consulted with you when he was writing the known conflict on the readme of project.

And is it a plan to migrate the existed functions to power-profiles-daemon or the plan should be to make power-profiles-daemon and tlp daemon compatible? How do you think?

[alex-tu-cc]

@linrunner How do you think to prevent tlp daemon changing the value of platform_profile? So that power-profiles-daemon and tlp daemon can co-exist.

[linrunner]

Hi @alex-tu-cc , thank you for caring.

Excuse me, but did you discuss the topic of how to keep the existed power saving experience offered by TLP on power-profiles-daemon with the power-profiles-daemon maintainer?

Not yet, but still on my list. I'm busy with 1.4 right now.

I am wondering if the maintainer consulted with you when he was writing the known conflict on the readme of project.

I have not heard from Sebastien yet.

And is it a plan to migrate the existed functions to power-profiles-daemon or the plan should be to make power-profiles-daemon and tlp daemon compatible? How do you think?

I'm not aware of Sebastien's plans. I myself have no plans to contribute to p-p-d at the moment. I think coexistence would be the best way in the medium term.

Last time I looked into the p-p-d sources it has controlled exactly two kernel features:

1. /sys/devices/system/cpu/cpufreq/energy_performance_preference - TLP 1.3.1: CPU_ENERGY_PERF_POLICY_ON_AC/BAT (activated in default.conf)
2. /sys/firmware/acpi/platform_profile - TLP 1.4: PLATFORM_PROFILE_ON_AC/BAT (not activated in default.conf, so no immeditate conflict)

Imho p-p-d is currently geared towards limiting power consumption under high or medium CPU loads, while TLP also takes care of idle and low load situations.

[linrunner]

@linrunner How do you think to prevent tlp daemon changing the value of platform_profile? So that power-profiles-daemon and tlp daemon can co-exist.

1. Option: TLP detects the running p-p-d and doesn't touch the above mentioned settings
2. Option: p-p-d detects the situation and warns the user

Or a synthesis of both ...