pipewire: many rtkit warnings

[dyfrgi]

Nixpkgs version

• Stable (24.11)

Describe the bug

When pipewire starts, it emits many warnings about RTKit.

These warnings did not occur when pulseaudio was the default because enabling Pulseaudio turns on rtkit.

Steps to reproduce

Set services.misc.graphical-desktop.enable, e.g. by setting services.xserver.enable. I assume just setting services.pipewire.enable will also do it.

Expected behaviour

no warnings

Screenshots

No response

Relevant log output

Feb 14 09:37:44 slab wireplumber[5189]: mod.rt: RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
Feb 14 09:37:44 slab wireplumber[5189]: mod.rt: RTKit does not give us MaxRealtimePriority, using 1
Feb 14 09:37:44 slab wireplumber[5189]: mod.rt: RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
Feb 14 09:37:44 slab wireplumber[5189]: mod.rt: RTKit does not give us MinNiceLevel, using 0
Feb 14 09:37:44 slab wireplumber[5189]: mod.rt: RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
Feb 14 09:37:44 slab wireplumber[5189]: mod.rt: RTKit does not give us RTTimeUSecMax, using -1
Feb 14 09:37:44 slab pipewire-pulse[5188]: mod.rt: RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
Feb 14 09:37:44 slab pipewire-pulse[5188]: mod.rt: RTKit does not give us MaxRealtimePriority, using 1
Feb 14 09:37:44 slab pipewire[5187]: mod.rt: RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
Feb 14 09:37:44 slab pipewire[5187]: mod.rt: RTKit does not give us MaxRealtimePriority, using 1
Feb 14 09:37:44 slab pipewire-pulse[5188]: mod.rt: RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
Feb 14 09:37:44 slab pipewire-pulse[5188]: mod.rt: RTKit does not give us MinNiceLevel, using 0
Feb 14 09:37:44 slab pipewire[5187]: mod.rt: RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
Feb 14 09:37:44 slab pipewire[5187]: mod.rt: RTKit does not give us MinNiceLevel, using 0
Feb 14 09:37:44 slab pipewire-pulse[5188]: mod.rt: RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
Feb 14 09:37:44 slab pipewire-pulse[5188]: mod.rt: RTKit does not give us RTTimeUSecMax, using -1
Feb 14 09:37:44 slab pipewire[5187]: mod.rt: RTKit error: org.freedesktop.DBus.Error.ServiceUnknown
Feb 14 09:37:44 slab pipewire[5187]: mod.rt: RTKit does not give us RTTimeUSecMax, using -1

Additional context

I suggest that the Pipewire module also set services.rtkit.enable, like the Pulseaudio module does.

Though, I'd also note that there's an upstream bug with rtkit in this setup which may stop it from actually doing the task correctly. heftig/rtkit#32. But probably the solution to that is for someone to fork rtkit as the maintainer is not responding.

System metadata

• system: "x86_64-linux"
• host os: Linux 6.6.76, NixOS, 24.11 (Vicuna), 24.11.714363.44534bc021b8
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.24.12
• channels(root): "nixos-24.11, nixos-hardware"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

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@K900 @Kranzes

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[K900]

That's intentional, most setups don't need rtkit with pipewire.

[dyfrgi]

Is there a pipewire config change that would also silence the warnings, by making it stop trying to talk to rtkit? Looks like libpipewire-module-rt has an option rtkit.enabled which defaults to true, so setting it to false in the three configs (pipewire, pipewire-pulse, wireplumber; maybe more with further services enabled, I'm not sure) would probably also silence the warnings by making them stop trying to talk to RTKit.

[K900]

Why, though?

[dyfrgi]

Log noise makes debugging other issues harder. I found this while digging through journalctl output for information related to a different issue and the yellow warning text stood out. The other issue is an interaction between systems so I can't look at the logs of just one or two units.

Looking at the pipewire module-rt code, it will prefer to directly set RT and nice if that's allowed and then will not check for RTKit at all, so I don't think that disabling it would have any user-visible impact except for reducing log noise. Unfortunately their check for whether they can use rtkit only checks for the presence of dbus, not the presence of an RTKit provider on that bus.

[eclairevoyant]

Hiding log messages also makes issues hard to debug.