Question

The real-time operating system, which of the following is the most suitable scheduling scheme? 
1. Round robin
2. First come first serve
3. Pre-emptive
4. Random scheduling 

Answer 1

Correct Answer - Option 3 : Pre-emptive

Pre-emptive is the most suitable scheduling scheme for the real-time operating system 

• Preemptive Scheduling is suitable for Real-Time Programming, as it will allow a real-time process to preempt a process currently running in the Kernel.
• A preemptive Kernel may be more responsive since there is less risk that a Kernel-mode process will run for arbitrarily long periods before relinquishing the processor to the waiting process.
• Real-time systems require that results be produced within a specified deadline. One of the key features of a Real-time system is its ability to respond to real-time processes as soon as the process requires CPU.
• As a result, the scheduler for the real-time system must support a priority-based algorithm with preemption.

• The round-robin (RR) scheduling algorithm is designed especially for timesharing systems.
• It is similar to FCFS scheduling, but preemption is added to enable the system to switch between processes.
• A small unit of time, called a time quantum or time slice, is defined.
• The ready queue is treated as a circular queue. The CPU scheduler goes around the ready queue, allocating the CPU to each process for a time interval of up to 1-time​ quantum.