RemoveIPC=

Controls whether System V and #POSIX IPC objects belonging to the user shall be removed when the user fully logs out. Takes a boolean argument. If enabled, the user may not consume IPC resources after the last of the user's sessions terminated. This covers System V semaphores, shared memory and message queues, as well as POSIX shared memory and message queues. Note that IPC objects of the root user and other system users are excluded from the effect of this setting. Defaults to "yes".
Also , nix-collect, garbage doesn't touch anything in /run/user/1000 dir so they re persistent by default
Leftover IPC (Inter-Process Communication) resources like shared memory segments and semaphores can occur when processes do not properly release them after use. It's important to clean these up to prevent resource leaks, which can lead to system performance issues or limits being reached
Shared Memory for data transfer and semaphores for sync and this can get a lot better with #rust
#systemd #linux #nixos
https://www.freedesktop.org/software/systemd/man/latest/logind.conf.html