1.First-come, first-served (FCFS) scheduling

2.Shortest-job first (SJF) scheduling

3.Priority scheduling

4.Round-robin scheduling

5.Multilevel queue scheduling

6.Multilevel feedback queue scheduling

- First-come, First-served (FCFS) scheduling

- Shortest-job-first (SJF) scheduling

- Priority-scheduling algorithm,

- Round-robin (RR) scheduling

The FCFS algorithm is nonpreemptive, the RR algorithm is preemptive. The SJF and priority algorithms may be either preemptive or nonpreemptive.

- Multilevel queue algorithms

- Multilevel feedback queues

Because such a wide variety of scheduling algorithms are available, we need methods to select among them. Analytic methods use mathematical analysis to determine the performance of an algorithm. Simulation methods determine performance by imitating the scheduling algorithm on a “representative” sample of processes, and computing the resulting performance.

Operating Systems supporting threads at the kernel level must schedule threads - not processes - for execution. This is the case with Solaris 2 and Windows 2000 where both systems schedule threads using preemptive priority based on scheduling algorithm including support for real-time threads. The Linux process scheduler also uses a priority-based algorithm with real-time supports as well. The scheduling algorithms for these three operating systems typically favor interactive over batch and CPU-bound processes.systems typically favor interactive over batch and CPU-bound processes.

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