CSC414 Assignment 3

which of the following statements are true? I. Shortest remaining time first scheduling may cause starvation II. Preemptive scheduling may cause starvation III. Round robin is better than FCFS in terms of response time

All of them

The real difficulty with SJF in short term scheduling is: a) it is too good an algorithm b) knowing the length of the next CPU request c) it is too complex to understand d) none of the above

Knowing the length of the next CPU request

The strategy of making processes that are logically runnable to be temporarily suspended is called: a) non preemptive scheduling b) preemptive scheduling c) shortest job first d) first come first served

Preemptive scheduling

Which of the following scheduling algorithms gives minimum average waiting time? a) FCFS b) SJF c) round robin d) priority

SJF

The most optimal scheduling algorithm is: a) FCFS b) SJF c) RR D) none

SJF (shortest job first)

Preemptive shortest job first scheduling is sometimes called: a) fast SJF scheduling b) EDF scheduling - earliest deadline first c) HRRN scheduling - highest response ratio next d) SRTN scheduling - shortest remaining time next

SRTN - shortest remaining time next

A solution to the problem of indefinite blockage of low - priority processes is: a) starvation b) wait queue c) ready queue d) aging

aging

Which of the following statements are true? I. Shortest remaining time first scheduling may cause starvation II. Preemptive scheduling may cause starvation. III. Round robin is better than FCFS in terms of response time

all of them

Scheduling is: a) allowing a job to use the processor b) making proper use of the processor c) all of the mentioned d) non of the above

allowing a job to use the processor

Complex scheduling algorithms a) are very appropriate for very large computers b) use minimal resources c) use a small number of resources d) all of the above

are very appropriate for very large computers //large computers are overloaded with a greater number of processes

The portion of the process scheduler in an operating system that dispatches processes is concerned with: a) assigning ready processes to CPU b) assigning ready processes to waiting queue c) assigning runnning processes to blocked queue d) all of the above

assigning ready processes to CPU

Orders are processed in the sequence they arrive if _______ rule sequences the jobs

first come, first served

The FIFO algorithm: a) first executes the job that came in last in the queue b) first executes the job that came in first in the queue c) first executes the job that needs minimal processor d) first executes the job that has maximum processor needs

first executes the job that came in first in the queue

'Aging' is: a) keeping track of cache contents b) keeping track of what pages are currently residing in memory c) keeping track of how many times a given page is referenced d) increasing the priority of jobs to ensure termination in a finite time

increasing the priority of jobs to ensure termination in a finite time

one of the disadvantages of the priority scheduling algorithm is that: a) it schedules in a very complex matter b) its scheduling takes up a lot of time c) it can lead to some low priority process waiting indefinitely for the CPU d) none of the above

it can lead to some low priority process waiting indefinitely for the CPU

The FCFS algorithm is particularly troublesome for ______ a) time sharing systems b) multiprogramming systems c) multiprocessor systems d) operating systems

multiprogramming systems // in a time sharing system each user needs to get a share of the CPU at regular intervals

There are 10 different processes running on a workstation. Idle processes are waiting for an input event in the input queue. Busy processes are scheduled with the Round-Robin timesharing method. Which out of the following quantum times is the best value for small response times? a) tQ = 15ms b) tQ = 40ms c) tQ = 45ms d) tQ = 50ms

tQ = 15ms

An SJF algorithm is simply a priority algorithm where the priority is: a) the predicted CPU burst b) the inverse of the predicted CPU burst c) the current CPU burst d) anything the user wants

the predicted CPU burst //the larger the burst the lower the priority

With round robin scheduling algorithm in a time shared system, a) using very large time slices converts it into First come First served scheduling algorithm b) using very small time slices converts it into First come First served scheduling algorithm c)using extremly small time slices increases performance d) using very small time slices converts it into Shortest Job First algorithm

using very large time slices converts it into First come First served scheduling algorithm //all the processes will be able to be completed