Which Scheduling Algorithm Is Best?

What is a disk scheduling algorithm?

Disk scheduling is done by operating systems to schedule I/O requests arriving for the disk.

Disk scheduling is also known as I/O scheduling.

Multiple I/O requests may arrive by different processes and only one I/O request can be served at a time by the disk controller.

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What are examples of batch processing?

Batch processes generate a product but the sequential processes need not necessarily generate a product. Some examples of batch processes are beverage processing, biotech products manufacturing, dairy processing, food processing, pharmaceutical formulations and soap manufacturing.

Which scheduling algorithm has minimum average waiting time?

SJFSJF is optimal in that it gives the minimum average waiting time for a given set of processes. The real difficulty with SJF is knowing the length of the next CPU burst. For long-term (job) scheduling in a batch system, the length of process time could be specified by a user.

What are batch processing systems?

Batch processing is the processing of transactions in a group or batch. No user interaction is required once batch processing is underway. This differentiates batch processing from transaction processing, which involves processing transactions one at a time and requires user interaction.

How do you calculate waiting time?

Calculating Average Waiting TimeHence, waiting time for P1 will be 0.P1 requires 21 ms for completion, hence waiting time for P2 will be 21 ms.Similarly, waiting time for process P3 will be execution time of P1 + execution time for P2, which will be (21 + 3) ms = 24 ms .More items…

What is OS waiting time?

Waiting time is the total time spent by the process in the ready state waiting for CPU. For example, consider the arrival time of all the below 3 processes to be 0 ms, 0 ms, and 2 ms and we are using the First Come First Serve scheduling algorithm. Then the waiting time for all the 3 processes will be: P1: 0 ms.

Which scheduling algorithm is best for batch processing?

Scheduling of Batch Systems The two most commonly used algorithms for batch processing system are FCFS (First Come First Served) and SJF (Shortest Job First). A. FCFS First Come, First Served (FCFS), is the simplest scheduling algorithm, FIFO simply queues processes in the order that they arrive in the ready queue.

Is FCFS preemptive or Nonpreemptive?

First Come First Serve (FCFS) Jobs are executed on first come, first serve basis. It is a non-preemptive, pre-emptive scheduling algorithm. Easy to understand and implement. Its implementation is based on FIFO queue.

What is shortest job first algorithm?

Shortest Job First (SJF) is an algorithm in which the process having the smallest execution time is chosen for the next execution. … It significantly reduces the average waiting time for other processes awaiting execution. The full form of SJF is Shortest Job First.

Which disk scheduling algorithm is best?

Disk Scheduling AlgorithmsFirst Come -First Serve (FCFS) All incoming requests are placed at the end of the queue. … Shortest Seek Time First (SSTF) In this case request is serviced according to next shortest distance. … Elevator (SCAN) This approach works like an elevator does. … Circular Scan (C-SCAN) … C-LOOK.

What is the most optimal scheduling?

Abstract: After studying various CPU scheduling algorithms in Operating System, Round Robin scheduling algorithm is found to be most optimal algorithm in timeshared systems because of the static time quantum that is designated for every process.

Is there any difference between Sstf and scan scheduling If yes then justify?

C-SCAN algorithm provides low variance in average waiting time and response time. Whereas SSTF provides high variance in average waiting time and response time.

What is the priority scheduling algorithm?

Priority Scheduling is a method of scheduling processes that is based on priority. In this algorithm, the scheduler selects the tasks to work as per the priority. The processes with higher priority should be carried out first, whereas jobs with equal priorities are carried out on a round-robin or FCFS basis.

What is starvation OS?

Starvation is the problem that occurs when high priority processes keep executing and low priority processes get blocked for indefinite time. In heavily loaded computer system, a steady stream of higher-priority processes can prevent a low-priority process from ever getting the CPU.

Which algorithms tends to minimize the process flow time?

Discussion ForumQue.Which of the following algorithms tends to minimize the process flow time ?b.Shortest Job Firstc.Earliest Deadline Firstd.Longest Job FirstAnswer:Shortest Job First1 more row