Package: pipewire Version: 0.3.51-1 Severity: wishlist Dear Maintainer,
During the investigation of a scheduler priority issue in WirePlumber, Niklāvs Koļesņikovs lamented Debian's use of RTKit for setting scheduling priority[1], rather than a group with increased rlimits as recommended in the Pipewire wiki.[2] Niklāvs noted some of the benefits:[3] 1. RTKit does not support Flatpak, whereas RLIMITs do work inside user namespaces. 2. RTKit usually does not go above priority 19 (though it should be noted that there's some level of disagreement in the pro audio community on what the appropriate priority for audio daemons [and applications] should be). 3. RTKit is known to sometimes think that its canary thread is starving when the system exits S3 sleep state, this will cause RTKit to revoke realtime from all clients until at least the particular client restarts (possibly also RTKit restart but I'm not immediately sure if it's that bad). The exact mechanism is unknown but speculated to happen if the canary thread or the watchdog ends up frozen at particular point making it perceive a huge realtime scheduling delay. 4. RTKit is actually abandoned with no upstream being interested or active in fixing bugs such as the previously described canary starvation issue. Worst of all the same will likely be true if a security issue is discovered. Additionally: 5. It would allow raising the memlock rlimit, not handled by RTKit. 6. It would allow creating the WirePlumber GLib thread pool threads at a nice level matching the main thread and avoiding the "Failed to set scheduler settings: Operation not permitted" currently printed by wireplumber on startup.[4] Perhaps it would make sense for the pipewire package to create a pipewire group, configure the suggested rlimit values in a /etc/security/limits.d/ file, and document use of the group in README.Debian? Thanks for considering, Kevin [1]: https://gitlab.freedesktop.org/pipewire/wireplumber/-/issues/255#note_1393924 [2]: https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/Performance-tuning#rlimits [3]: https://gitlab.freedesktop.org/pipewire/wireplumber/-/issues/255#note_1394696 [4]: https://gitlab.freedesktop.org/pipewire/wireplumber/-/issues/255 -- System Information: Debian Release: bookworm/sid APT prefers testing-debug APT policy: (990, 'testing-debug'), (990, 'testing'), (500, 'unstable-debug'), (500, 'stable-debug'), (500, 'unstable'), (101, 'experimental'), (1, 'experimental-debug') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 5.18.0-rc7 (SMP w/4 CPU threads; PREEMPT) Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set Shell: /bin/sh linked to /usr/bin/dash Init: systemd (via /run/systemd/system) LSM: AppArmor: enabled Versions of packages pipewire depends on: ii init-system-helpers 1.62 ii libpipewire-0.3-modules 0.3.51-1 ii pipewire-bin 0.3.51-1 pipewire recommends no packages. pipewire suggests no packages. -- no debconf information
