Virtual University Forum

Today Paper Total Questions = 26 Total Marks = 40 Total MCQs of 1 Mark = 20 Short Subjective Question of 2 Marks = 2 Subjective Question of 3 Marks = 2 Subjective Questions of 5 Marks = 2 1) define data race detection is static and dynamic if it is define in detail ? marks 5 2) priority scheduling algorithm is indefinite blocking or starvation define it why? marks 5 3)define any three queues that are used in multifeedback scheduling?3 marks 4)Process synchronization of concurrent process or thread for shared data and shared resource? 3 marks 5)similarities between process and thread execution? 2 marks 6)SJF preemptive average waiting time ?2 mark

Today Paper Total Questions = 26 Total Marks = 40 Total MCQs of 1 Mark = 20 Short Subjective Question of 2 Marks = 2 Subjective Question of 3 Marks = 2 Subjective Questions of 5 Marks = 2 1) define data race detection is static and dynamic if it is define in detail ? marks 5 2) priority scheduling algorithm is indefinite blocking or starvation define it why? marks 5 3)define any three queues that are used in multifeedback scheduling?3 marks 4)Process synchronization of concurrent process or thread for shared data and shared resource? 3 marks 5)similarities between process and thread execution? 2 marks 6)SJF preemptive average waiting time ?2 marks

Question No: 21      ( Marks: 2 )   Define Waiting time with respect to CPU Scheduling? Question No: 22      ( Marks: 3 )   True or False? (and explain): the Multi-Level Feedback Queue (MLFQ)       scheduling algorithm is the same as Shortest-Job-First. Question No: 23      ( Marks: 5 )  What does the term ‘input redirection’ mean? Write down the basic syntax for input, output and error redirection of UNIX/LINUX system. Q..There are number of scheduling algorithms which belong to difficult scheduling scheme may belong to preemptive and non-preemptive section . What is the main difference b/w preemptive and non-preemptive? marks 5 Q..Hardware solution to critical section involve of swap instruction .Write the code of specific implementation of mutual exclusion using swap instruction ?

Mcq's were 80% from virtualians file. Questions that I can recall: 1. Which algorithm decreases the wait times for short processes much more than it increases the wait times for long processes? Answer is SJF. 2.Had to provide the shortcomings for this one: do { key=true; while(key == true) Swap(lock,key); Critical section lock=false; Remainder section } while(1); 3. Critical Section: A piece of code in a cooperating process in which the process may updates shared data (variable, file, database, etc.). Is it true or not? 4. Which command is used to view the current process information?

20th dec paper at 2pm of cs604 MCQs were almost 85% from virtualians Q1. which term do u think best fit the situation where a process keep continuously waiting after requesting to enter its critical section? 2 marks Q2. How can u suspend a foreground process in UNIX/LINUX? 2 marks Q3. do u think that in multilevel queing the problem of starvation can be solved using multilevel feedback queuing? if yes justify. 3 marks Q4. Write atleast 3 advantages of preemptive scheduling algorithms in terms of response time , waiting time, priority etc . and also suggest names of algos having that property? 3marks Q5. following data given , describe the scheduling order for the processes in FCFS, SJF, and in RR with quantum=2? marks 5 P1 5 p2 4 P3 3 P4 2 P5 8 Q.6 What are the events that u think when occur CPU scheduling is needed? discuss and highlight those points where CPU scheduling is done? marks 5

Q1: how many types of threads? aur ya kesy OS ka sath connect hoti hn. Q2: give any two real life example of critical problem? Q3: rearrange these Scheduling algorithm in higher to low priority.. SJF FCFS Round Robin Priority Q4: page number 106 pe code likha hy wo paper mn aya houa tha.us mn se shortcoming ko identify krna tha. Q5: When a process communicate between a related to unrelated (not different only same system) es mn batana tha ka ka PCI ka konsa tool use ho ga communication ka liya aur kuyn ho ga.