>А compressed tmpfs по прежнему безнадежно поломана, да?откуда там сжатие, когда там есть своп?
https://man.freebsd.org/cgi/man.cgi?tmpfs
"""
If the system becomes low on memory and swap is configured (see swapon(8)), the system can transfer file data to swap space, freeing memory for other needs. Metadata, including the directory content, is never swapped out by the current implementation. Keep this in mind when planning the mount limits, especially when expecting to place many small files on a tmpfs mount.
"""
Может это имели ввиду https://man.freebsd.org/cgi/man.cgi?mdmfs