Scheduling Criteria in Operating System:
There are many scheduling algorithms and various criteria to judge their performance. Different algorithms may favor different types of processes. Some criteria are as follows:
- CPU utilization: CPU must be as busy as possible in performing different tasks. CPU utilization is more important in real-time system and multi-programmed systems.
- Throughput: The number of processes executed in a specified time period is called throughput. The throughput increases for short processes. It decreases if the size of processes is huge.
- Turnaround Time: The amount of time that is needed to execute a process is called turnaround time. It is the actual job time plus the waiting time.
- Waiting Time: The amount of time the process has waited is called waiting time. It is the turnaround time minus actual job time.
- Response Time: The amount of time between a request is submitted and the first response is produced is called response time.
A CPU scheduling algorithm should try to maximize the following:
- CPU utilization
- Throughput
A CPU scheduling algorithm should try to minimize the following:
- Turnaround time
- Waiting time
- Response time
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