Training Trains Internship
Student login
← Operating Systems learning path
Operating Systems · Module 3 of 10

CPU scheduling

Decide which process runs next.

📖 Key ideas

  1. The scheduler picks the next process for the CPU.
  2. FCFS: first come, first served.
  3. SJF: shortest job first (minimises average waiting time).
  4. Round Robin: time slices (quantum) in turn.
  5. Priority scheduling may cause starvation; aging fixes it.
💡 Real-life example: CPU scheduling is a doctor's queue: first come, shortest consultation first, or fixed minutes each.
FCFSFirst Come First Served
SJFShortest Job First
Round RobinTime-sliced turns
StarvationProcess never gets the CPU