RamJet

RamJet is a small C daemon inspired by Rice/Ananicy. It scans /proc and applies Ananicy-style .rules, .types definitions.

Build

Dependencies are only the C toolchain and Linux headers:

make
make test

Install:

sudo make install

The daemon reads configuration from /etc/ananicy.d and runs in the foreground, which makes it suitable for systemd and runit.

Supported rule fields

Rules support:

• name
• type
• nice (-20 to 19)
• io-class or ioclass (realtime, best-effort, idle)
• ionice (0 to 7)
• cgroup (Not working and maybe will be deprecated in a future)
• oom_score_adj (-1000 to 1000)

Types support the same scheduling fields and are inherited by rules when a rule does not define the corresponding value itself.

Cgroups

Cgroup handling remains intentionally limited to the legacy v1 CPU controller at /sys/fs/cgroup/cpu. On systems using cgroup v2 only, RamJet starts normally but reports cgroups as unavailable (and maybe will be deprecated in a future).

Service files

Systemd:

sudo install -m 644 systemd/ramjet.service /etc/systemd/system/ramjet.service
sudo systemctl daemon-reload
sudo systemctl enable --now ramjet.service

For runit, place the runit/ directory under the appropriate service directory.

Changes in this version

• Fixed Linux ionice class numbers.
• Fixed the valid nice range.
• Stopped processing the main thread twice.
• Hardened /proc PID parsing against malformed/overflowing directory names.
• Propagated scheduling/application errors instead of always returning success.
• Added oom_score_adj application and inheritance.
• Replaced shell-based ionice invocation with direct execvp.
• Removed the bundled cJSON dependency in favor of a small parser for the flat Ananicy JSON objects RamJet consumes.
• Made duplicate rule/type/cgroup definitions replace previous entries deterministically.
• Prevented shutdown from deleting pre-existing cgroups.
• Rejected unsafe cgroup names containing path separators.
• Fixed stale systemd/runit paths and arguments.