For anyone interested: https://github.com/systemd/systemd/pull/1116
"This moves PID 1 into a new "init.scope" implicit scope unit in the root slice. This is necessary since on the unified hierarchy cgroups may either contain subgroups or processes but not both. PID 1 hence has to move out of the root cgroup (strictly speaking the root cgroup is the only one where processes and subgroups are still allowed, but in order to support containers nicey, we move PID 1 into the new scope in all cases.) This new unit is also used on legacy hierarchy setups. It's actually pretty useful on all systems, as it can then be used to filter journal messages coming from PID 1, and so on." ________________________________________ From: systemd-devel <[email protected]> on behalf of Lennart Poettering <[email protected]> Sent: Sunday, August 16, 2026 11:02 AM To: Demi Marie Obenour <[email protected]> Cc: systemd development <[email protected]>; Linux cgroups development <[email protected]>; Alyssa Ross <[email protected]> Subject: [EXTERNAL] Re: [systemd-devel] Purpose of init.scope On Mi, 29.07.26 16:13, Demi Marie Obenour ([email protected]) wrote: > What is the purpose of having PID 1 in init.scope? Is it functionally > necessary, or is it solely for consistency with when systemd is > running in a container or as a user service manager? PID 1 needs to live somehwere, so that's where we put it. Where else would you put it? Lennart -- Lennart Poettering, Berlin
