rlm - Resource Limit Manager

A Linux tool for managing process resource limits using cgroups v2. Available as both CLI and GUI.

Features

• Limit memory, CPU, and I/O bandwidth for running processes
• Run commands with resource limits applied
• Named profiles for reusable limit configurations
• Works with systemd cgroup delegation (no root required for user processes)

Supported Distros

Any Linux with cgroups v2 and systemd:

Distro	Version
Ubuntu	22.04+
Debian	12+
Fedora	31+
RHEL / Rocky / Alma	9+
Arch	current
openSUSE Tumbleweed	current

Older versions may work with systemd.unified_cgroup_hierarchy=1 kernel boot param.

Installation

From packages (recommended)

Download from Releases:

# Debian/Ubuntu
sudo dpkg -i rlm_*.deb rlm-gtk_*.deb

# Fedora/RHEL
sudo rpm -i rlm-*.rpm rlm-gtk-*.rpm

From source

cargo install --path cli
cargo install --path gtk-gui
./install-desktop.sh  # desktop entry and icon

CLI Usage

Limit a running process

# By PID
rlm limit --pid 1234 --memory 512M --cpu 50%

# By name (limits all matching processes)
rlm limit --name firefox --memory 2G

# With I/O limits
rlm limit --pid 1234 --memory 1G --io-read 50M --io-write 20M

Run a command with limits

rlm run --memory 1G --cpu 100% -- ./my-program arg1 arg2

# Using a profile
rlm run --profile browser -- firefox

Remove limits

rlm unlimit --pid 1234
rlm unlimit --name firefox

View managed processes

rlm status

List profiles

rlm profiles

Diagnose setup issues

rlm doctor

Export/import profiles

# Export profiles to a file
rlm export profiles.yaml

# Import profiles from a file
rlm import profiles.yaml
rlm import profiles.yaml --overwrite  # Replace existing

Preview changes (dry-run)

rlm limit --pid 1234 --memory 512M --dry-run

GUI Usage

Launch the GUI with:

rlm-gtk

Pages:

• Status - managed processes and their limits
• Limit - apply limits by PID or name
• Run - launch commands with limits
• Profiles - saved limit configurations
• About - version and license info

Configuration

Create ~/.config/rlm/config.yaml:

profiles:
  browser:
    memory: "4G"
    cpu: "200%"
  dev:
    memory: "8G"
    cpu: "400%"
    io_read: "100M"
    io_write: "50M"

Built-in Presets

Preset	Memory	CPU	I/O
Light	512M	25%	-
Medium	2G	50%	50M/25M
Heavy	4G	100%	100M/50M
Browser	4G	75%	-

Use with: rlm run --profile Medium -- ./command

Cgroup Delegation (non-root usage)

The .deb and .rpm packages automatically configure cgroup delegation. Just log out and back in after installing.

For manual/source installs, enable delegation:

sudo mkdir -p /etc/systemd/system/user@.service.d
sudo tee /etc/systemd/system/user@.service.d/delegate.conf << EOF
[Service]
Delegate=cpu memory io
EOF
sudo systemctl daemon-reload

Then log out and back in. Run rlm doctor to verify.

License

Apache 2.0