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What is SRTF in operating system?
SRTF, Which Stands for Shortest Remaining Time First is a scheduling algorithm used in Operating Systems, which can also be called as the preemptive version of the SJF scheduling algorithm. The process which has the least processing time remaining is executed first.
Does SRTF cause starvation?
In SRTF, job with the shortest CPU burst will be scheduled first. Because of this process, It may cause starvation as shorter processes may keep coming and a long CPU burst process never gets CPU.
Is SRTF and SRTN same?
Shortest remaining time, also known as shortest remaining time first (SRTF), is a scheduling method that is a preemptive version of shortest job next scheduling. In this scheduling algorithm, the process with the smallest amount of time remaining until completion is selected to execute.
How is SRTF scheduling calculated?
- Average Turn Around time = (1 + 5 + 4 + 16 + 9) / 5 = 35 / 5 = 7 unit.
- Average waiting time = (0 + 1 + 2 + 10 + 6) / 5 = 19 / 5 = 3.8 unit.
What is the average waiting time for SRTF?
Average Waiting Time = (9 + 0 + 15 + 2)/4 = 26/4 = 6.5 milliseconds. If we schedule according to non-preemptive scheduling of the same set of processes then: Average Waiting Time = 7.75 milliseconds….Shortest Remaining Time First (SRTF)
| Process | Arrival Time | Burst Time |
|---|---|---|
| p2 | 1 | 4 |
| p3 | 2 | 9 |
| p4 | 3 | 5 |
What is context switching?
Context Switching involves storing the context or state of a process so that it can be reloaded when required and execution can be resumed from the same point as earlier. After some time again a context switch occurs and Process 2 is switched out and Process 1 is switched in again.
Is Round Robin better than FCFS?
Sometimes FCFS algorithm is better than the other in short burst time while Round Robin is better for multiple processes in every single time. However, it cannot be predicted what process will come after. The target is to know which algorithm is more suitable for the certain process.
Which scheduler is called as job scheduler?
Long-Term Scheduler is also known as Job Scheduler. Short-Term Scheduler is also known as CPU Scheduler. 3. In Long-Term Scheduler, the programs are setup in the queue and as per the requirement the best one job is selected.
What is the average turn around time with SRT?
In SRT, the process with smallest runtime to complete (i.e remaining time) is scheduled to run next, including new arrivals. In SRT, a running process may be preempted by new process with shorter estimated run time….Consider the following 4 jobs.
| Job | Turn Around Time |
|---|---|
| 3 | 25-3 = 22 |
| 4 | 10-4 = 6 |
| 48 |
How is FCFS calculated in OS?
Using the FCFS scheduling algorithm, these processes are handled as follows. Step 1) At time=1, P3 arrives. P4 is still executing. Hence, P3 is kept in a queue….How FCFS Works? Calculating Average Waiting Time.
| Process | Burst time | Arrival time |
|---|---|---|
| P2 | 2 | 5 |
| P3 | 8 | 1 |
| P4 | 3 | 0 |
| P5 | 4 | 4 |
Why SRTF is called a preemptive scheduling?
The Preemptive version of Shortest Job First(SJF) scheduling is known as Shortest Remaining Time First (SRTF). With the help of the SRTF algorithm, the process having the smallest amount of time remaining until completion is selected first to execute.
Is context switching good?
The key reason context switching is bad is because it takes time and effort to get into focus. So every time we switch tasks, we lose energy that we wouldn’t have lost if we had just stayed on one task. Fatigue is not the only problem that arises from context switching. Productivity suffers, too.