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By far the simplest CPU-scheduling algorithm is the first-come, first-served (FCFS) scheduling algorithm. With this scheme, the process that requests the CPU first is allocated the CPU first. The implementation of the FCFS policy is easily managed with a FIFO queue. When a process enters the ready queue, its PCB is linked onto the tail of the queue. When the CPU is free, it is allocated to the process at the head of the queue. The running process is then removed from the queue. The code for FCFS scheduling is simple to write and understand. The average waiting time under the FCFS policy, however, is often quite long. Consider the following set of processes that arrive at time 0, with the length of the CPU-burst time given in milliseconds:
What else can I help you with?
Which of the following scheduling algorithms could result in starvation?
SJhortest job First
What is CPU sheduling algorithm?
Basically,this is a need in case of multiprogramming.For optimum utilization of CPU it should be utilised in the meanwhile time when some process is in waiting state for some I/O or waiting for some event to occur. So,for this many programs should be in memory in waiting state so that CPU can be allocated to some other process for optimum utilization of CPU. A schedule(time table in broad sense) which will decide Cpu will be allocated to which process when some previous process is in waiting state. Now this schedule is designed according to some criteria(algorithm) to decide CPU will be allocated to which process. Some Algorithms: 1.First Come First Serve(FCFS) 2.Shortest Job Scheduling(SJS) 3.RoundRobin Scheduling(RRS)
What scheduling algo is used for real time OS?
Cooperative schedulingPreemptive scheduling Rate-monotonic schedulingRound-robin schedulingFixed priority pre-emptive scheduling, an implementation of preemptive time slicingFixed-Priority Scheduling with Deferred PreemptionFixed-Priority Non-preemptive SchedulingCritical section preemptive schedulingStatic time schedulingEarliest Deadline First approachStochastic digraphs with multi-threaded graph traversal
What is disk scheduling?
>File systems must be accessed in an efficient manner >As a computer deals with multiple processors over a period of time, a list of request to access the disk build up >The operating system uses a disk scheduling technique to determine which request to satisfy. Disk scheduling techniques: (1)First-come, First-served (2)Shortest-seek-time-first(SSTF) (3)scan 4 c-scan 5
One girl poem. What does the first stanza mean?
Provide one example of each of the three types of relations people can have with the environment (interact with it, adapt to it, and modify it). In three to five sentences, explain why each example fits its category.
Explain first fit algorithm?
A "first fit" algorithm is any algorithm which doesn't care about how "good" a solution is, it just returns the first one that works.
What do you mean by scheduling algorithm in OS?
its the algorithm that tells the os what to process next.goes according to :shortest job firstshortest remaining time firstround robin- first in first out system
Which is best scheduling algorithm?
There isn't a single "best" scheduling algorithm, as the effectiveness of a scheduling algorithm depends on the specific requirements and constraints of the system in question. Common algorithms include Round Robin, Shortest Job First, and Priority Scheduling, each with its strengths and weaknesses. For real-time systems, Rate Monotonic Scheduling may be preferred, while for batch processing, Shortest Job First could be more efficient. Ultimately, the best choice depends on factors such as system load, response time requirements, and resource availability.
What is a multilevel scheduling?
Multilevel scheduling is a CPU scheduling algorithm that organizes processes into multiple priority levels or queues, allowing for different scheduling strategies at each level. Each queue can have its own scheduling algorithm, such as first-come, first-served or round-robin, enabling the system to optimize performance for various types of workloads. Processes are typically promoted or demoted between levels based on their behavior and resource needs. This approach enhances responsiveness and efficiency by balancing the needs of both high-priority and low-priority tasks.
None of the disk-scheduling disciplines except First Come First Serve algorithm is truly fair starvation may occur explain why this assertion is true?
New requests for the track over which the head currently resides can theoretically arrive as quickly as these requests are being serviced
What is the simplest scheduling algorithm?
The simplest scheduling algorithm is the First-Come, First-Served (FCFS) algorithm. In this approach, processes are executed in the order they arrive in the ready queue, without preemption. This means once a process starts executing, it runs to completion before the next process begins. While easy to implement, FCFS can lead to issues like the "convoy effect," where shorter processes wait for longer ones, increasing overall waiting time.
What relation between priority and shortest job first?
In that work system, the shortest job gets higher priority because more gets accomplished in any amount of time. If you have two hours to do 4 tasks and one task will take five minutes, one will take 30 minutes, one will take an hour and one will take an hour and a half, by using the shortest job first method, you will accomplish three tasks in those two hours and part of the fourth task. If you do the longest job first, you will accomplish the task that takes an hour and a half, then only part of the one hour task, but nothing on the 5 minute or 30 minute tasks. That means that by doing the shortest jobs first, you will accomplish three times as many tasks as you will by doing the longest jobs first.
What is an example of innovation by Google?
Google's first -and historically major development- was its search engine's algorithm.
Could a scheduling algorithm maximizing a throughput?
Yes, a scheduling algorithm can be designed to maximize throughput, which refers to the number of tasks completed in a given time period. Such algorithms prioritize task execution based on factors like resource availability, task priority, and execution time, aiming to minimize idle time and maximize resource utilization. Examples include Shortest Job First (SJF) and Round Robin scheduling. However, achieving maximum throughput may require trade-offs, such as increased waiting times for some tasks.
What relation holds between priority and first come first serve algorithm?
In scheduling algorithms, the priority method assigns tasks based on their importance, while the First-Come, First-Serve (FCFS) algorithm processes tasks in the order they arrive, regardless of priority. This means that in FCFS, a lower-priority task can delay a higher-priority one if it arrives first. Consequently, the two algorithms can lead to different performance outcomes, particularly in terms of response time and overall system efficiency. In contrast, priority scheduling aims to minimize wait times for high-priority tasks, potentially at the cost of lower-priority ones.
What is Short job first?
short job first (SJF) is a job scheduling algorithm where shorter jobs are favored for being serviced first. this increases the overall system's number of processed jobs but has the disadvantage that long jobs can face starvation in waiting state irrespective to their wait time..
What do you mean by non-preemptive shortest job first scheduling explain with an example?
Non pre-emptive means once CPU starts executing one process, it will not be taken out of the CPU until it is terminated or it has to wait for some event. In preemptive SJF scheduling, current running process is moved to the ready queue when a new process with a shorter CPU burst joins the ready queue.
