Introduction

sched_ext is a Linux kernel feature that allows BPF programs to implement custom CPU scheduling policies, replacing or extending the default scheduler at runtime without modifying kernel source.

This book covers:

  • A repository overview and high-level architecture guide
  • A complete conceptual explainer of how sched_ext works
  • Patch-by-patch analysis across all 42 patches in the upstream submission
  • New to sched_ext? Start with How sched_ext Works for a complete conceptual overview of the architecture, data flow, and BPF ops interface.
  • Want the big picture first? Read the High-Level Study Guide for a structured summary of the patch series goals and design decisions.
  • Ready to dive into patches? Use the Patch Study section to trace the implementation patch by patch.

Commit messages and diffs are preserved verbatim from the original mailing list submissions.