Phase 3: Processes & Scheduling
Everything running on your Linux system is a process. Understanding how processes are created, how the kernel decides which one runs next, and how they communicate through signals unlocks your ability to debug, tune, and understand almost any system behavior.
What You'll Learn
1. What is a Process?
PID, PPID, fork(), exec() — how programs become processes.
Intermediate2. Process States
Running, sleeping, zombie, uninterruptible — what each means.
Intermediate3. Process Scheduling (CFS)
How the Completely Fair Scheduler decides what runs next.
Intermediate4. Nice Values & Priority
Influence scheduling with nice, renice, chrt, and ionice.
Intermediate5. Signals
What kill really does, SIGTERM vs SIGKILL, signal delivery internals.
Intermediate6. /proc Filesystem
How the kernel exposes process state as virtual files.
Intermediate7. Daemons
What background processes are and how they're created.
Intermediate8. Socket Activation
How systemd activates services only when connections arrive.
IntermediateFrequently Asked Questions
What will I learn here?
This page covers the core concepts and techniques you need to understand the topic and progress confidently to the next lesson.
How should I use this page?
Start with the overview, then follow the section links to deepen your understanding. Use the table of contents on the right to jump to specific sections.
What should I read next?
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