Q1. Scheduling Criteria: Waiting time - amount of time a process has been waiting in the ready queue. Consider the following scenario to the above criterion. 10 process, each requiring 100 units of CPU time to complete. Assume that I/O time for a process is negligible. Also, the all processes present at time t. a) In a round Round Robin strategy each process is assigned to CPU for (i) 10 units in trial 1, (ii) 20 units in trial 2. b) Swapping a process out /in takes 1.5 units. c) Evaluate waiting time in ready queue for each process strategy (i) and strategy (ii). d) Which strategy would you consider as best and why? 57 APR 13 tv 8 O zoom W

Q1. Scheduling Criteria: Waiting time - amount of time a process has been waiting in the ready queue. Consider the following scenario to the above criterion. 10 process, each requiring 100 units of CPU time to complete. Assume that I/O time for a process is negligible. Also, the all processes present at time t. a) In a round Round Robin strategy each process is assigned to CPU for (i) 10 units in trial 1, (ii) 20 units in trial 2. b) Swapping a process out /in takes 1.5 units. c) Evaluate waiting time in ready queue for each process strategy (i) and strategy (ii). d) Which strategy would you consider as best and why? 57 APR 13 tv 8 O zoom W

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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Four processes arrive at the same time with their priorities, execution times and I/O times given in the table below. Assuming a Round-Robin Scheduling works with a quantum time of 3, but the scheduler selects the process with highest priority from the queue (NOT those arrived earliest), other than currently pre-empted process, at each turn; a-)Draw the timeline for CPU- and I/O- bursts for these processes b-)Calculate average turn-around time
Question 3 Suppose that the following processes arrive for execution at the times indicated. Each process has the shown priorities and will run for the amount of time listed (all times are in ms) Process Arrival Time Burst Time Priority Queue P1 15 3 P2 20 3 P3 20 20 2 P4 25 10 2 P5 30 2 P6 35 15 1 To schedule the execution of these process, a preemptive multi-level queue scheduler is designed to apply the following policy at each decision instant (namely whenever a new process arrives and whenever a burst completes execution) : • Serve the process at the highest priority queue first • If two processes are in the same queue: . If they have different remaining time, follow the SRTF policy • If they have same remining time, follow a RR policy (slice time = 2 ms) Given the above: 1. Show the scheduling order of the bursts using a Gantt chart.
2 ) Consider two processes PO and P1 which shares a global variable 'flag'. The value of flag is either 0 or 1 where 0 indicates "PO is permitted to enter into critical section" and 1 indicates for P1. Assume PO and P1 are concurrent processes which are executing the following code with initial value of flag as 0. while(1) { While (flag!=i); flag=1-i; } If PO starts executing first, which of the following holds by the above execution? A) Mutual Exclusion B) B) Progress C) C) Bounded waiting D) D) Both (A) and (C) Justify your answer.
In a computer system five processes are attempting to proceed with three resource types. The total units of system resources are: (8,9,7). The maximum demands for every process are: P1(3,1,1), P2(3,3,2), P3(5,3,2), P4(5,1,2), P5(8,4,3). The current allocation is: P1 (0,1,1), P2 (2,1,1), P3 (3,1,2), P4 (1,1,1), and P5 (2,3,2). Is this state a safe state? Explain your answer. Please explain in great detail so i can understand .
A car manufacturing company manufactures 10 cars. The process that goes into manufacturing a car involves various stages. Let's assume the car number C31, starts its assembling process for each of its parts. There is proper system counter maintained for each car that basically represents the five phases During each phase, the counter points to the next level of the assembling process and currently the counter is pointing to Phase 4. The company is maintaining a policy of Priority Scheduling to complete the task. Considering the car number as the process id and the phases as the instruction numbers, design the process control block for the car.
Given in Table 1 is a set of five (5) processes with the priority, length of the CPU-burst time, and arrival time. Table 1 Process Arrival Time (ms) Burst Time (ms) Priority* P1 3 P2 1 2 1 P3 3 P4 7 P5 8 8 4. *Note: • A smaller priority number implies a higher priority. a) Compute the Waiting Time (WT) of each process in Table 1, and also compute their Average Waiting Time, for each of the following scheduling algorithms. i. Shortest Job First (SJF). ii. Pre-emptive Priority (PP) iii. Round Robin (RR) with quantum = 3 (ms).
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Consider the following set of processes, with the length of the CPU-burst time given in milliseconds, Process CPU Burst Time P1 P2 1 P3 P4 1 P5 7 The processes are assumed to have arrived in the order P1, P2, P3, P4, P5 all at time 0. Draw four Gantt charts illustrating the (i) execution of these processes using SJF and RR (quantum = 1) scheduling. (ii) What is the waiting time of each process for each of the scheduling algorithms in part (i)? %3D
2. Consider the following set of processes, each with its arrival time, burst time, and priority: Process Arrival Time Burst Time Priority 0 6 [IT] 1 4 2 8 3 2 Apply the Multilevel Queue scheduling algorithm with two queues, one for high-priority processes (P1 and P2) and one for low-priority processes (P3 and P4), and a time quantum of 3 for the high-priority queue and 5 for the low-priority queue. Calculate the average waiting time and turnaround time for each queue, as well as the overall average waiting time and turnaround time. P1 P2 P3 P4 3 1 2 4
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An operating system uses a total of two units of the resource R for each of its three user processes. The operating system uses a total of 12 units of R. The absolute minimum number of R units that must be used to guarantee that there are no deadlocks is
rocess Arrival Time CPU Burst Time Priority PI P2 P3 P4 5 0 7 4 6 7 5 7 HIGH LOW VERY HIGH MEDIUM (a) Draw a Gantt chart of the process scheduling using preemptive, priority-based scheduling. Determine the waiting time & the turnaround time of individual processes and the average waiting time & the average turnaround time. In case of a tie, use arrival times to break the tie