Question

The processor itself is not a resource, therefore the OS is not involved in deciding how much of the processor time is used for the execution of a user program

a. True
b. False

Answer 1

b= false.

Step-by-step explanation:

The operating system (OS) is a program that perform basic functions like sending output to the display screen and controlling peripheral devices.

Operating system can be classified into: multiprocessing(this allow a program to be run on more than one Central Processing Unit), multi-threading( this support a single program in different parts to run concurrently), multi-user(here,two or more users run programs at the same time), and real time( instant response to inputs).

The amount of time for which a central processing unit used in processing instructions an operating system is known as PROCESSOR TIME.

Operating System, OS is actively involved in determining how much of the processor time is used for the execution of a user program.

Answer 2

False

Step-by-step explanation:

In computing, a resource can be defined as a component with limited or varying size/capability. Every computer has a processor whose capability is measured by the number of instructions it can perform in a given unit of time (Clock speed), The number of cores, the size of cache memory and of course the make i.e. AMD or Intel.

One of the functions of the Operating systems in relation to CPU is CPU Scheduling. This is whereby the process manager determines the process to be allocated the resource (CPU) basing on the suitable criteria.

The scheduling criteria is based on:

a. CPU Utilization ensures that the CPU is busy all the time.

b. Throughput is the number of processes that can be executed per unit given time.

c. Turn Around Time which is the time it takes to get the final output after the process has been allocated the CPU.

d. Waiting Time defined as the length of time a process takes in the ready queue.

e. Response Time defined as the difference in time between the arrival time and the time it starts executing.

The algorithms selected aims at:

1. Maximize CPU utilization

2. Maximize throughput

3. Minimize Turn Around Time, Waiting Time and Response Time

The operating system uses the scheduling criteria to determine the best algorithm to be used to give a number of processes.

These algorithms can be grouped as either preemptive or non-preemptive.

Preemptive means once the process has been allocated to the CPU and can be interrupted before it completes its burst time. Examples include:

a. Round Robin

b. Shortest Remaining Time First (SRTF)

c. Priority Scheduling

Non-preemptive scheduling algorithm works in a way that once a process has been allocated the CPU it cannot be halted or paused until it has completed its burst time. Examples include:

a. First Come First Serve (FCFS)

b. Shortest Job First (SJF)

c. Priority Scheduling