What is Priority Scheduling
Priority Scheduling is a non-preemptive or preemptive CPU scheduling algorithm where each process is assigned a priority, and the CPU is allocated to the process with the highest priority.
Lower number = higher priority (unless specified otherwise)
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Can be Preemptive or Non-Preemptive
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Priority is either assigned (static) or calculated dynamically.
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Starvation is possible if low-priority processes wait too long.
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Aging technique can be used to prevent starvation by increasing priority over time.
Example (Non-Preemptive Priority Scheduling)
Given:
| Process |
Arrival Time |
Burst Time |
Priority |
| P1 |
0 |
10 |
3 |
| P2 |
2 |
1 |
1 |
| P3 |
3 |
2 |
4 |
| P4 |
5 |
1 |
2 |
1. At time 0, only P1 has arrived → run P1
2. At time 10, P2, P3, and P4 have arrived.
3. Then run P4 (priority 2)
4. Then run P3 (priority 4)
