System Software and Operating System

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Important Points

  •  Burst time is total time required for execution, which is given in problem
  • Arrival time is moment at which job is submitted into a queue , which is given in problem
  • start time is time at which procees starts its execution
  • Finish time of every process is calulated by addition of start time and burst time of that process
  • wait time of every process is calculated by subtraction of start  time and arrival time of that  process
  • Turn around time of every process is calculated by subtraction of finish time and arrival time
  • Avearge wait time is calculated by average of wait time of all processes.'
  • Average turn around time is calculated by average of turn around time of all processes. 
  • Belady's Anomaly - If there are three free frames and we are finding the total page faults , this page fault should be reduced if we increase number of free frames then number of page faults should be decreased. When this does not happen , then exception is called belady's anomaly.

Consider the following set of processes with the length of CPU  burst time and arrival time given in milli seconds
 

Process

Burst Time

Arrival Time

P1

5

1.5

P2

1

0

P3

2

2

P4

4

3

Illustrate the execution of these process using FCFS CPU Scheduling algorithems. Also calculate wait timeand turn around timeof each process and calculate average waiting time and average turn around time for above situation. Also draw a gantt chart.

 Solution :

Process

(1)

Burst Time

(2)

Arrival Time

(3)

Start Time

(4)

Wait Time

(5)

(4)-(3)

 

Finish Time

(6)

(4)+(2)

Turn Around Time

(7)

(6)-(3)

P1

5

1.5

1.5

0

6.5

5

P2

1

0

0

0

1

1

P3

2

2

6.5

5.5

8.5

6.5

P4

4

3

8.5

5.5

12.5

9.5

 

Now calculate average wait time 

Average Wait time =10/4=2.5

average turn around time=22/4=5.5

Gantt Chart 

P2

         

P1

P3

P4

0               1                1.5                     6.5                       8.5              12.5   
 

In the shaded area CPU is idle and not doing any thing because no process is in ready queue 

Consider the following set of processes with the length of CPU  burst time and arrival time given in milli seconds
 

Process

Burst Time

Arrival Time

P1

2

1

P2

3

2

P3

5

0

 

Illustrate the execution of these process using pre-emptive SJF CPU Scheduling algorithems. Also calculate wait time and turn around timeof each process and calculate average waiting time and average turn around time for above situation

Solution

Process

(1)

Burst Time

(2)

Arrival Time

(3)

Start Time

(4)

Wait Time

(5)

(4)-(3)

 

Finish Time

(6)

(4)+(2)

Turn Around Time

(7)

(6)-(3)

P1

2

1

1

0

3

2

P2

3

2

3

1

6

4

P3

5

0

0

0+(6-1)=5

10

10

 

Total wait time =6 
Total turn around time =20
Average wait time=6/3=2
Average turn around time=20/3=6.66

 Consider the following set of processes with the length of CPU  burst time and arrival time given in milli seconds

Process

Burst Time

Arrival Time

Priority

P1

3

1

3(highest)

P2

2

2

2

P3

5

0

1

 

Illustrate the execution of these process using non-premptive priority CPU Scheduling algorithems. Also calculate wait time and turn around time of each process and calculate average waiting time and average turn around time for above situation.

 Solution :

Process

(1)

Burst Time

(2)

Arrival Time

(3)

Priority

Start Time

(4)

Wait Time

(5)

(4)-(3)

 

Finish Time

(6)

(4)+(2)

Turn Around Time

(7)

(6)-(3)

P1

3

1

  3

5

4

8

7

P2

2

2

2

8

6

10

8

P3

5

0

1

0

0

5

5

Total wait time= 10

Average Wait time =10/3=3.33
 

Total Turn around time = 20

average turn around time=20/3=6.66

 Assume there are three free frames , find out belady's anomaly for 4 free frames, If reference string is 1,2,3,4,1,2,5,1,2,3,4,5. Use LRU

Solution

RS

1

2

3

4

1

2

5

1

2

3

4

5

F1

1

1

1

4

4

4

5

5

5

3

3

3

F2

 

2

2

1

1

1

1

1

1

1

4

4

F3

 

 

3

3

3

2

2

2

2

2

2

5

PF

1

2

3

4

1

2

5

---

----

3

4

5

Total Page Fault = 10

Now page fault for 4 frames

RS

1

2

3

4

1

2

5

1

2

3

4

5

F1

1

1

1

1

1

1

1

1

1

1

1

5

F2

 

2

2

2

2

2

2

2

2

2

2

2

F3

 

 

3

3

3

3

5

5

5

5

4

4

F4

 

 

 

4

4

4

4

4

4

3

3

3

PF

1

2

3

4

---

---

5

---

----

3

4

5

Total page fault =8

Hence we can say there is no belady's anomaly.

System software is a type of computer program (software) that is designed to provide a platform to run a computer's hardware and application programs whereas the operating system (OS) is the system software that manages all the programs in a computer. We have numerous amounts of System software mcq as well as operating system mcq.  Check and have practice System Software quizzes questions during precious moments before the competitive exam. Our latest Study Material and collection of System software mcq questions from latest updated syllabus of UGC NET CS enables your confidence to score well. Besides study material we have system software and operating system mcq questions in Solved Previous Papers and online mock test. This makes the readers familiar with the exam pattern and the type of questions asked, and makes them prepare to face the exam with confidence. On one click, you will be able to know the answers are correct or incorrect along with explanation of correct answers. Click on “ACCESS NOW” link to view and practice UGC NET CS: System software MCQs as well as operating system mcqs practices questions which are listed under it.

List of sub-topics covered in System Software and Operating System are-

System Software:Machine, Assembly and High-Level Languages;Compilers and Interpreters;Loading, Linkingand Relocation; Macros,Debuggers. Main Function of Operating Systems:Operating System Structure, Operations and Services; System Calls,Operating-System Design and Implementation; System Boot. .Threads:Multicore Programming,Multithreading Models,Thread Libraries,Implicit Threading,Threading Issues. Scheduling: CPU Scheduling Criteria and Algorithms;Thread Scheduling,Multiple-Processor Scheduling,Real-Time CPU Scheduling. Deadlocks:Deadlock Characterization,Methods for Handling Deadlocks,Deadlock Prevention, Avoidance and Detection; Recovery from Deadlock. Memory Management: Virtual memory, Allocation,Swapping ,paging, fragmentation,Segmentation, Demand Paging,Page Replacement,Allocation of Frames,Thrashing,Memory-Mapped Files. Storage Management:Mass-Storage Structure,Disk Structure, Schedulingand Management, RAID Structure. Input/Output Systems: Access Methods,Directory and Disk Structure; File-System Mounting,File Sharing,File-System Structureand Implementation; Directory Implementation,Allocation Methods,Free-Space Management,Efficiency and Performance; Recovery, I/O Hardware, Application I/O Interface, Kernel I/O Subsystem,Transforming I/O Requests to Hardware Operations. Operating Systems (Linux):Design Principles,Kernel Modules, Process Management, Scheduling, Memory Management, File Systems,Input and Output; Interprocess Communication, Network Structure. Windows Operating Systems:Design Principles, System Components,Terminal Services and Fast User Switching; FileSystem, Networking. Who can get benefit of this section which includes System Software mcq and operating system mcq. System Software Questions and Answers: System Software MCQ Questions Answers can be used by any student who is preparing for PhD entrance exam, pre PhD entrance exam, entrance exam or any other such exam. Any student who is preparing for DOEACC (A, B or C level) exams can also use System Software questions answers for preparation of his/her exams. System Software mcq can be useful for the students who are engaging any undergraduate or post graduate degree in computer science like BE, ME , B.Tech, M.Tech, .BSc, MSc, or many other such degree System Software  quizzes with answers and detailed explanation can also be useful for the students who are preparing for competitive exam or like GATE Computer Science, NTA UGC NET Computer Science, PGT exam, public sector undertaking(PSU), IES or any other such exam. System Software MCQs questions and operating system mcq can also be used by any candidate who wants to gain credits in Software Engineering in BS Computer science or MS Computer science. Software Engineering objective type questions answers can be used for the preparation of National Eligibility Test (NET) and State Eligibility Test (SET). You can download System Software and Operating System mcq pdf from this site. You can get quizzes of System Software questions and answers EBook. Various Search Terms Used For This Section Are:

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