udev-plotter

A lightweight visualization tool that parses raw udevadm monitor output into an interactive, offline HTML report.

Why?

Reading raw udevadm monitor logs can be a bit time consuming and confusing as many things can happen in parallel, this tool gives a visual way for visual people to understand their udevadm monitor logs.

udev-plotter turns those massive log dumps into a timeline so you can visually spot bottlenecks and optimize your boot time or udev rules.

Setup

1. Install the CLI tool

You can install the python package using pip or pipx. Running from the repository root:

pipx install .
# or using a virtual environment
python3 -m venv venv
source venv/bin/activate
pip install .

2. Set up the boot log collector (Optional)

To capture events during the actual system boot sequence, you'll need a background service. We provide an install script that sets up a simple systemd/SysVinit service to capture udevadm monitor output:

sudo ./install.sh

This will start recording boot events to /var/log/udev-boot-monitor.log. You can remove it later by running sudo ./uninstall.sh.

Usage

Once you have a log file (either from the boot service or by manually running udevadm monitor > my-log.log), feed it to the plotter:

udev-plotter /var/log/udev-boot-monitor.log

By default, this generates an interactive HTML report in the output/ folder. Just open the resulting .html file in any web browser.

Filtering Options

The udev-plotter UI provides several ways to drill down into the noise:

• Text Search: Type into the search bar to instantly filter events by devpath, driver, or interface.
• Event Source Toggle: Switch between raw KERNEL events, processed UDEV events, or view Both simultaneously to trace how kernel events are handled by user-space.
• Action Chips: Toggle specific udev actions (e.g., add, remove, bind, change) by clicking the colored action chips.
• Subsystem Histogram: The bar chart isn't just for show, click any subsystem bar (like block, usb, or net) to exclusively filter the timeline and table to that subsystem. Click it again to clear the filter.

Images speak more than words....