60 Questions
What does CPU utilization measure?
Percentage of time the CPU is busy processing a task
Why is it important to maximize CPU utilization?
To ensure the CPU is busy and working efficiently
What can high CPU utilization lead to?
Excessive competition for resources
How is throughput defined in CPU scheduling?
The number of tasks or processes completed within a specific period
Why is maximizing throughput important in batch processing environments?
To complete as many jobs as possible within a specific time frame
What does a high throughput indicate about the system?
System is processing tasks efficiently
In what scenario can too high CPU utilization lead to a system slowdown?
When there is excessive competition for resources
Which criterion reflects the efficiency and productivity of the system?
Throughput
How does maximizing throughput impact system performance?
It improves system performance and increases productivity
What happens if the CPU is idle most of the time?
Decreased system productivity
What is the purpose of minimizing turnaround time in CPU scheduling?
To improve user satisfaction and system efficiency
Which CPU scheduling algorithm prioritizes turnaround time by focusing on short and simple tasks?
Shortest Job First (SJF)
Why is minimizing waiting time important in CPU scheduling?
To reflect the efficiency of the scheduling algorithm
Which CPU scheduling algorithm prioritizes waiting time by giving higher priority to more important tasks?
Priority Scheduling
What is the significance of minimizing response time in CPU scheduling?
To ensure effective task processing
Which CPU scheduling algorithm targets response time by prioritizing tasks that require immediate attention?
Round Robin
In what type of systems is Round Robin scheduling algorithm effective?
Time-sharing systems
"Choosing the right algorithm for a particular situation is critical for maximizing what in CPU scheduling?"
Both user satisfaction and system efficiency
Why is prioritizing factors like turnaround time, waiting time, and response time essential in CPU scheduling algorithms?
To optimize system performance and user satisfaction
Which of the following statements about minimizing waiting time in CPU scheduling is true?
Short waiting times lead to improved user satisfaction.
What is the main task of a Long-Term Scheduler?
Selecting jobs from the pool and maintaining them in the ready queue
Which objective is NOT typically associated with process scheduling?
Minimizing response time
In a system with distinct policies for each queue, what task does the OS scheduler perform?
Moving tasks between the ready and run queues
What role does a Short-Term Scheduler play in process scheduling?
Deciding which process to run next
Which type of scheduler focuses on selecting processes from secondary memory and maintaining them in primary memory's ready queue?
Long-Term Scheduler
Which criterion in CPU scheduling measures the time it takes for a task to complete from the moment it is submitted to the system until it is fully processed and ready for output?
Turnaround Time
Which algorithm is NOT mentioned as prioritizing response time in CPU scheduling?
Shortest Job First (SJF)
Why is minimizing waiting time important in CPU scheduling?
It reflects the efficiency of the scheduling algorithm.
Which scenario can lead to a system slowdown due to CPU utilization?
High CPU utilization
What is the main objective of prioritizing factors like turnaround time, waiting time, and response time in CPU scheduling algorithms?
To improve user satisfaction and productivity
What is the primary role of the Long-Term scheduler in an operating system?
Controlling the degree of multiprogramming
Which scheduler is responsible for reducing the degree of multiprogramming in the system?
Medium-Term Scheduler
In CPU scheduling, what happens if the Short-Term scheduler makes a mistake and selects a job with a long CPU burst time?
All subsequent jobs will have to wait in a ready queue for a long period
Which criterion is reflected in CPU scheduling algorithms that prioritize turnaround time?
Predictability
What is the primary function of the Medium-Term Scheduler in an operating system?
Removing processes from memory and handling swapped out-processes
What type of scheduling algorithm is FCFS?
Non-preemptive
What scheduling algorithm is known for the Convoy effect?
Priority Scheduling
What is the primary difference between non-preemptive SJN and preemptive SJN scheduling algorithms?
Burst time selection
What is a characteristic of SJN scheduling?
Involves breaking ties using FCFS scheduling
Why is FCFS scheduling not considered very efficient?
It doesn't prioritize important tasks
Which scheduling algorithm is most likely to result in the lowest average waiting time?
Shortest Remaining Time First
In Priority Scheduling, what happens when a higher priority task arrives while a lower priority task is being executed?
The lower priority task is paused until the higher priority task completes
What is a significant disadvantage of the Round Robin scheduling algorithm?
It causes excessive context switching
Why is the Starvation Problem a notable concern in Priority Scheduling?
It causes longer waiting times for certain processes
Which CPU scheduling algorithm introduces the concept of preemptive execution based on process priorities?
Shortest Remaining Time First
What is the primary goal of multilevel queue scheduling in operating systems?
To efficiently handle different types of processes based on their characteristics
In multilevel queue scheduling, which type of processes are typically given the highest priority?
System processes
Which queue in the multilevel queue architecture is used for non-interactive processes that take longer to complete?
Background queue
How are processes sorted in multilevel queue scheduling?
By deadlines, priority, and I/O demands
Which type of queue in multilevel queue scheduling includes system processes like device drivers and interrupt handlers?
System queue
What is one of the challenges associated with implementing multilevel queue scheduling?
Preventing system instability due to improper design
What is a potential issue that could arise if a process is continuously assigned to a lower-priority queue in multilevel feedback queue scheduling (MLFQ)?
Starvation where the process never gets to run
Why is it essential to choose the appropriate scheduling algorithm for each queue in multilevel feedback queue scheduling (MLFQ)?
To prevent system instability and subpar performance
In multilevel feedback queue scheduling (MLFQ), how does the system prioritize processes based on their performance?
By adjusting priorities dynamically according to performance
What advantage does multilevel queue scheduling provide in distributing resources efficiently?
Ensuring crucial tasks are executed first based on their importance
What is a major advantage of using MLFQ scheduling in real-time systems?
Ensuring tasks complete within a specific time frame
Why is MLFQ scheduling considered to optimize CPU utilization effectively?
By prioritizing tasks based on their behavior
What is a key disadvantage associated with MLFQ scheduling in terms of system predictability?
Poor predictability
How does MLFQ scheduling address the issue of priority inversion?
By allowing lower-priority processes to hold resources
Which aspect of MLFQ scheduling contributes to its complexity in implementation?
Maintaining multiple queues with different priorities
Study Notes
CPU Utilization and Scheduling
- CPU utilization measures the percentage of time a CPU spends on executing instructions.
- High CPU utilization can lead to increased throughput, but excessive utilization can cause slowdowns.
Throughput and Performance
- Throughput is defined as the number of tasks completed per unit time in CPU scheduling.
- Maximizing throughput is crucial in batch processing environments to increase productivity.
- High throughput indicates a system can handle more tasks efficiently.
- However, too high CPU utilization can lead to system slowdowns.
CPU Scheduling Algorithms
- The criterion that reflects the efficiency and productivity of the system is throughput.
- Maximizing throughput impacts system performance by increasing task completion rates.
- Round Robin scheduling is effective in systems with time-sharing or interactive environments.
Process Scheduling
- The main task of a Long-Term Scheduler is to select processes from secondary memory and maintain them in primary memory's ready queue.
- A Short-Term Scheduler plays a crucial role in process scheduling by selecting processes from the ready queue and allocating the CPU.
- The OS scheduler performs the task of allocating the CPU to processes in a system with distinct policies for each queue.
Scheduling Objectives
- The primary objective of prioritizing factors like turnaround time, waiting time, and response time is to maximize system efficiency and productivity.
- Minimizing waiting time is essential to prevent starvation and ensure fairness in CPU scheduling algorithms.
CPU Scheduling Criteria
- Turnaround time measures the time from task submission to completion.
- Response time measures the time from task submission to first response.
- Waiting time measures the time a task spends waiting in the ready queue.
Scheduling Algorithms
- FCFS (First-Come-First-Served) is a non-preemptive scheduling algorithm where tasks are executed in the order they arrive.
- SJN (Shortest Job Next) is a scheduling algorithm that prioritizes short tasks to minimize waiting time.
- Priority Scheduling is a preemptive scheduling algorithm that prioritizes tasks based on their priority.
- Round Robin is a time-quantum-based scheduling algorithm that allocates a fixed time slice to each task.
- Multilevel Feedback Queue (MLFQ) is a scheduling algorithm that uses multiple queues with different time slices to prioritize tasks based on their performance.
Multilevel Feedback Queue Scheduling
- Multilevel queue scheduling prioritizes processes based on their performance and allocates resources efficiently.
- The primary goal of multilevel queue scheduling is to distribute resources efficiently among different types of processes.
- System processes like device drivers and interrupt handlers are typically given the highest priority in multilevel queue scheduling.
Learn about the criteria for CPU scheduling, focusing on CPU utilization. Understand the importance of maximizing CPU utilization for efficient system performance and productivity.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
