CPU Scheduling Lecture Notes

Introduction to CPU Scheduling

• Importance of CPU Scheduling
  • Fundamental topic in Operating Systems (OS)
  • Key for computer science exams
• Definition: CPU scheduling is the process of determining which process will use the CPU at a given time.
  • Essential for multi-programmed operating systems to enhance productivity.

Basics of CPU Scheduling

• Single Processor Systems:
  • Only one process can run at a time.
  • Other processes must wait until the CPU is available.
• Multi-Processor Systems:
  • Multiple processes can run simultaneously.
  • Objective is to maximize CPU utilization by ensuring a process is always running.

Need for CPU Scheduling

• Issue with Idle CPU:
  • When a process waits for an I/O operation, the CPU remains idle, leading to wasted time and decreased productivity.
• Goal:
  • Prevent the CPU from being idle by allowing other processes to utilize it when one is waiting.

Mechanism of CPU Scheduling

• Process Management:
  • Several processes are kept in memory at the same time.
  • When one process waits, the CPU is reassigned to another process, ensuring continuous utilization.
• Scheduling:
  • Involves assigning time slots for processes to use the CPU.
  • Rules and algorithms guide which process gets the CPU when.

CPU Scheduling Algorithms

• Variety of Algorithms:
  • Different algorithms require different scheduling rules based on the situation.
  • Will study various algorithms in detail in upcoming lectures.

Conclusion

• Next Steps:
  • Further exploration into CPU scheduling terms, methods, and algorithms in future lectures.
• Final Note: Understanding CPU scheduling is crucial for optimizing CPU usage and improving system performance.