Project 3: Process Scheduler Visualization Tool

A tool that visualizes the Linux scheduler in real-time, showing which processes are running on which CPUs, context switches, runqueue depth, and scheduling decisions.

Quick Reference

Attribute Value
Primary Language See main guide
Alternative Languages N/A
Difficulty Level 3: Advanced
Time Estimate 2 weeks
Knowledge Area OS Scheduler / Kernel Internals
Tooling Linux Scheduler (CFS)
Prerequisites C, understanding of basic scheduling concepts

What You Will Build

A tool that visualizes the Linux scheduler in real-time, showing which processes are running on which CPUs, context switches, runqueue depth, and scheduling decisions.

Why It Matters

This project builds core skills that appear repeatedly in real-world systems and tooling.

Core Challenges

  • Reading scheduler data from /proc and tracefs (maps to kernel/user data interfaces)
  • Understanding CFS vruntime and load balancing (maps to scheduling algorithms)
  • Tracking context switches in real-time (maps to process lifecycle, interrupts)
  • Correlating CPU time with priority (maps to scheduler internals)
  • Visualizing multi-core scheduling (maps to SMP considerations)

Key Concepts

  • Completely Fair Scheduler (CFS): “Linux Kernel Development” Ch. 4 - Robert Love
  • Process states and transitions: “Operating Systems: Three Easy Pieces” Ch. 4 - Arpaci-Dusseau
  • /proc filesystem: “The Linux Programming Interface” Ch. 12 - Michael Kerrisk
  • CPU affinity: “The Linux Programming Interface” Ch. 35 - Michael Kerrisk

Real-World Outcome

Deliver a working demo with observable output that proves the feature is correct.

Implementation Guide

  1. Reproduce the simplest happy-path scenario.
  2. Build the smallest working version of the core feature.
  3. Add input validation and error handling.
  4. Add instrumentation/logging to confirm behavior.
  5. Refactor into clean modules with tests.

Milestones

  • Milestone 1: Minimal working program that runs end-to-end.
  • Milestone 2: Correct outputs for typical inputs.
  • Milestone 3: Robust handling of edge cases.
  • Milestone 4: Clean structure and documented usage.

Validation Checklist

  • Output matches the real-world outcome example
  • Handles invalid inputs safely
  • Provides clear errors and exit codes
  • Repeatable results across runs

References

  • Main guide: TRACK_A_OS_KERNEL_PROJECTS.md
  • “Linux Kernel Development” by Robert Love