Podcast
Questions and Answers
What is a notable disadvantage of using First Come First Serve (FCFS) scheduling?
What is a notable disadvantage of using First Come First Serve (FCFS) scheduling?
- It can lead to a convoy effect. (correct)
- It allows preemption of currently running processes.
- It ensures fairness among processes.
- Processes are executed in the order they arrive.
What is the primary objective of maximizing CPU utilization in scheduling algorithms?
What is the primary objective of maximizing CPU utilization in scheduling algorithms?
- To reduce the turnaround time for individual processes.
- To keep the CPU as busy as possible. (correct)
- To minimize the response time for processes.
- To ensure all processes get equal time on the CPU.
How is turnaround time calculated?
How is turnaround time calculated?
- Completion Time + Arrival Time
- Turnaround Time + Waiting Time
- Completion Time - Burst Time
- Completion Time - Arrival Time (correct)
Which of the following scheduling criteria focuses on the responsiveness of the system?
Which of the following scheduling criteria focuses on the responsiveness of the system?
In what situation does a non-preemptive scheduling algorithm present challenges?
In what situation does a non-preemptive scheduling algorithm present challenges?
What is the key function of throughput in scheduling algorithms?
What is the key function of throughput in scheduling algorithms?
Which characteristic distinguishes non-preemptive scheduling from preemptive scheduling?
Which characteristic distinguishes non-preemptive scheduling from preemptive scheduling?
What does fairness in scheduling aim to achieve?
What does fairness in scheduling aim to achieve?
What scheduling algorithm does the provided data primarily illustrate?
What scheduling algorithm does the provided data primarily illustrate?
Which process has the highest turnaround time in the given data?
Which process has the highest turnaround time in the given data?
In the context of non-preemptive priority scheduling, what happens when a new process with a higher priority arrives?
In the context of non-preemptive priority scheduling, what happens when a new process with a higher priority arrives?
Which of the following accurately describes the SJF scheduling algorithm?
Which of the following accurately describes the SJF scheduling algorithm?
In which scenario would preemptive priority scheduling be advantageous?
In which scenario would preemptive priority scheduling be advantageous?
How is the priority determined in a priority scheduling algorithm?
How is the priority determined in a priority scheduling algorithm?
Which of the following statements about preemptive scheduling is true?
Which of the following statements about preemptive scheduling is true?
What is one benefit of non-preemptive priority scheduling compared to the preemptive version?
What is one benefit of non-preemptive priority scheduling compared to the preemptive version?
What is the average waiting time for the processes P1, P2, and P3 when they arrive in the order P1, P2, P3?
What is the average waiting time for the processes P1, P2, and P3 when they arrive in the order P1, P2, P3?
When the processes arrive in the order P2, P3, P1, what is the average waiting time calculated?
When the processes arrive in the order P2, P3, P1, what is the average waiting time calculated?
In the scenario with processes P1, P2, P3, what is the completion time for process P3 when they arrive in the order P1, P2, P3?
In the scenario with processes P1, P2, P3, what is the completion time for process P3 when they arrive in the order P1, P2, P3?
Which of the following formulas is used to calculate the waiting time for a process?
Which of the following formulas is used to calculate the waiting time for a process?
What is the average turnaround time for the processes given with burst times of P1=21, P2=3, P3=6, and P4=2?
What is the average turnaround time for the processes given with burst times of P1=21, P2=3, P3=6, and P4=2?
If the arrival times for processes P1, P2, P3, P4, and P5 are 0, 1, 2, 3, and 4 respectively, what is the waiting time for P4?
If the arrival times for processes P1, P2, P3, P4, and P5 are 0, 1, 2, 3, and 4 respectively, what is the waiting time for P4?
What is the turnaround time for process P2 with a burst time of 3 and an arrival time of 1?
What is the turnaround time for process P2 with a burst time of 3 and an arrival time of 1?
When processes come in the order P1, P2, P3, what is the waiting time for process P2?
When processes come in the order P1, P2, P3, what is the waiting time for process P2?
What is the average completion time for three processes with burst times of P1 = 24, P2 = 3, and P3 = 3 when ordered as P1, P2, P3?
What is the average completion time for three processes with burst times of P1 = 24, P2 = 3, and P3 = 3 when ordered as P1, P2, P3?
What is a potential disadvantage of non-preemptive priority scheduling?
What is a potential disadvantage of non-preemptive priority scheduling?
In the example provided, which process has the highest priority?
In the example provided, which process has the highest priority?
What does Round Robin scheduling primarily utilize to manage processes?
What does Round Robin scheduling primarily utilize to manage processes?
Which process has the shortest turnaround time in the examples provided?
Which process has the shortest turnaround time in the examples provided?
In preemptive priority scheduling, when can a process be interrupted?
In preemptive priority scheduling, when can a process be interrupted?
From the provided data, which process experiences the highest waiting time?
From the provided data, which process experiences the highest waiting time?
What is the impact of burst time on completion time for a process?
What is the impact of burst time on completion time for a process?
What characterizes a preemptive scheduling algorithm?
What characterizes a preemptive scheduling algorithm?
What is the purpose of context switching in a preemptive scheduling system?
What is the purpose of context switching in a preemptive scheduling system?
In round robin scheduling, what does 'time quantum' refer to?
In round robin scheduling, what does 'time quantum' refer to?
What characterizes multilevel queue scheduling?
What characterizes multilevel queue scheduling?
What is the main advantage of the round robin scheduling algorithm?
What is the main advantage of the round robin scheduling algorithm?
How is the waiting time for a process calculated in scheduling?
How is the waiting time for a process calculated in scheduling?
Which of the following is NOT a characteristic feature of round robin scheduling?
Which of the following is NOT a characteristic feature of round robin scheduling?
Study Notes
Non-preemptive Scheduling
- Non-preemptive algorithms prevent processes from being interrupted once in the running state until they complete their time allocation.
Scheduling Criteria
- CPU Utilization: The goal is to keep the CPU active, ideally between 40-90% for optimal performance.
- Throughput: Measures how many processes are completed in a certain time frame.
- Turnaround Time: Total time taken for process execution, calculated as Completion Time - Arrival Time.
- Waiting Time: Total time spent in the ready queue, found by subtracting burst time from turnaround time.
- Response Time: Duration from submission of a request until the first response is received.
- Fairness: Ensures equal CPU sharing among processes.
Scheduling Algorithm Optimization Criteria
- Maximize CPU utilization
- Maximize throughput
- Minimize turnaround time
- Minimize waiting time
- Minimize response time
Types of Scheduling Algorithms
- First Come First Serve (FCFS)
- Shortest Job First (SJF)
- Priority Scheduling
- Round Robin (RR) Scheduling
- Multilevel Queue Scheduling
- Multilevel Feedback Queue Scheduling
First Come First Serve (FCFS) Scheduling
- Processes are executed in the order they arrive.
- Simple to implement but can lead to high average wait times, especially in time-sharing systems.
- Disadvantage: Convoy effect occurs when short processes wait for a long process, reducing CPU utilization.
FCFS Example
- When processes P1 (24), P2 (3), and P3 (3) arrive in order:
- Gantt Chart: P1 (0-24), P2 (24-27), P3 (27-30)
- Waiting Time: P1 = 0, P2 = 24, P3 = 27; Average = 17 ms
- If they arrive as P2, P3, P1:
- Gantt Chart: P2 (0-3), P3 (3-6), P1 (6-30)
- Waiting Time: P1 = 6, P2 = 0, P3 = 3; Average = 3 ms
Shortest Job First (SJF)
- Selects processes with the least execution time first.
- Can be both non-preemptive and preemptive.
Priority Scheduling
- Assigns a priority to each process, highest priority gets CPU first.
- Can lead to starvation for low-priority processes.
- Can be either preemptive or non-preemptive.
Round Robin (RR) Scheduling
- A preemptive scheduling algorithm where each process runs for a set time slice (quantum) before being preempted.
- Context switching saves states of preempted processes.
Multilevel Queue Scheduling
- A strategy that separates processes into distinct queues based on task type, with each queue having different scheduling priorities.
- Processes are permanently assigned to a specific queue.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the principles of non-preemptive scheduling algorithms and their impact on CPU utilization, turnaround time, and fairness. This quiz covers the criteria for scheduling performance and the optimization goals in operating systems. Test your understanding of non-preemptive scheduling methods and their significance.
