What is CPU Scheduling and its types?

CPU scheduler schedules a process which is loaded in memory (Ready state) to run in CPU.

Types of Scheduling Algorithm

FCFS

• FCFS is implemented using queue which serves in first in first out manner.
• Processes are assigned to the CPU based on their order of requests (order of arrivals)
• “Ready queue” maintains all processes in their arrival orders.
• FCFS scheduling is non-preemptive algorithm.

Shortest Job First (SJF) Or Shortest Process Next

• SJF schedules a process based on the selection of smallest (shortest) burst time of processes.
• SJF is non-preemptive algorithm.

Shortest Remaining Time First (SRTF)

• SRTF scheduling is similar to SJF, only the difference is SRTF can preempt the job while it is executing in CPU if any smaller job needs to execute compared to remaining time of current job.

Round Robin Scheduling (RR)

It is the preemptive scheduling in which every process gets executed in a cyclic way, i.e., in this a particular time slice is allocated to each process which is known as time quantum.