Recent questions and answers in Operating System - GATE Overflow

+69 votes

7 answers

1

GATE2005-72
Consider the following code fragment: if (fork() == 0) { a = a + 5; printf("%d, %p n", a, &a); } else { a = a - 5; printf ("%d, %p n", a,& a); } Let $u,v$ be the values printed by the parent process and $x,y$ be the values printed by the child process. Which one ... $u + 10 = x \text{ and } v = y$ $u + 10 = x \text{ and } v != y$

answered 5 hours ago in Operating System by Shyam Nandan Kumar (51 points) | 9.6k views

+14 votes

4 answers

2

GATE2016-2-20
In which one of the following page replacement algorithms it is possible for the page fault rate to increase even when the number of allocated frames increases? LRU (Least Recently Used) OPT (Optimal Page Replacement) MRU (Most Recently Used) FIFO (First In First Out)

answered 1 day ago in Operating System by swapnilbaviskar10 (55 points) | 1.9k views

+37 votes

4 answers

3

GATE2015-1-9
The following two functions $P1$ and $P2$ that share a variable $B$ with an initial value of $2$ ... $B$ can possibly take after the execution is______________________.

answered 3 days ago in Operating System by Vinit Gore (65 points) | 3.2k views

+1 vote

1 answer

4

UGCNET-dec2008-ii-22
If holes are half as large as processes, the fraction of memory wasted in holes is: (A) 2/3 (B) 1/2 (C) 1/3 (D) 1/5

answered 4 days ago in Operating System by abhinav kumar (127 points) | 201 views

+1 vote

1 answer

5

ISRO2020-57
The hardware implementation which provides mutual exclusion is Semaphores Test and set instructions Both options None of the options

answered 5 days ago in Operating System by `JEET Boss (18.8k points) | 263 views

+1 vote

1 answer

6

ISRO2020-26
The operating system and the other processes are protected from being modified by an already running process because they run at different time instants and not in parallel they are in different logical addresses they use a protection algorithm in scheduler every address generated by the CPU is being checked against the relocation and limit register

answered 5 days ago in Operating System by habedo007 Active (2.8k points) | 125 views

+1 vote

3 answers

7

ISRO2020-25
What is compaction refers to a technique for overcoming internal fragmentation a paging technique a technique for overcoming external fragmentation a technique for compressing the data

answered 5 days ago in Operating System by Ashwani Kumar 2 Boss (16.3k points) | 90 views

+2 votes

1 answer

8

ISRO2020-31
Three CPU-bound tasks, with execution times of $15,12$ and $5$ time units, respectively arrive at times $0,t$ and $8$ respectively. If the operating system implements a shortest remaining time first scheduling algorithm, what should be the value of $t$ to have $4$ context switches? Ignore the context switches at time $0$ and at the end. $0<t<3$ $t=0$ $t<=3$ $3<t<8$

answered 5 days ago in Operating System by STUDYGATE2019 (249 points) | 115 views

+1 vote

2 answers

9

ISRO2020-29
An aid to determine the deadlock occurrence is resource allocation graph starvation graph inversion graph none of the above

answered 5 days ago in Operating System by `JEET Boss (18.8k points) | 101 views

+2 votes

0 answers

10

ISRO2020-30
Consider the following page reference string. $1\ 2\ 3\ 4\ 2\ 1\ 5\ 6\ 2\ 1\ 2\ 3\ 7\ 6\ 3\ 2\ 1\ 2\ 3\ 6\ $ What are the minimum number of frames required to get a single page fault for the above sequence assuming LRU replacement strategy? $7$ $4$ $6$ $5$

asked 5 days ago in Operating System by Satbir Boss (23.7k points) | 138 views

+1 vote

1 answer

11

ISRO2020-28
Dispatch latency is defined as the speed of dispatching a process from running to the ready state the time of dispatching a process from running to ready state and keeping the CPU idle the time to stop one process and start running another one none of these

answered 5 days ago in Operating System by `JEET Boss (18.8k points) | 79 views

+2 votes

1 answer

12

ISRO2020-27
Which of the following algorithms defines time quantum? shortest job scheduling algorithm round robin scheduling algorithm priority scheduling algorithm multilevel queue scheduling algorithm

answered 5 days ago in Operating System by `JEET Boss (18.8k points) | 63 views

0 votes

3 answers

13

MadeEasy Test Series: Operating System - Memory Management
Consider a machine with byte addressable memory 32 bits virtual addresses, 32 bits physical addresses and 4 KB page size. If a two-level page table system is used where each page table occupies one page and page table entries of 4 B each, then the memory overhead for this machine is ________ KB please explain.

answered 6 days ago in Operating System by Ritwik (485 points) | 379 views

+3 votes

1 answer

14

ISRO2018-20
Determine the number of page faults when references to pages occur in the order $1,2,4,5,2,1,2,4.$ Assume that the main memory can accommodate $3$ pages and the main memory already has the pages $1$ and $2,$ with page $1$ brought earlier than page $2.$ (assume LRU i.e., Least-Recently-Used algorithm is applied) $3$ $4$ $5$ None of the above

answered Jan 10 in Operating System by Lakshman Patel RJIT Veteran (58.5k points) | 1.3k views

+4 votes

3 answers

15

ISRO-DEC2017-69
Consider a disk sequence with $100$ cylinders. The request to access the cylinder occur in the following sequence : $4,34,10,7,19,73,2,15,6,20$ Assuming that the head is currently at cylinder $50$, what is the time taken to satisfy all requests if it takes $2\,ms$ to move from one cylinder to adjacent one and shortest seek time first policy is used? $190$ $238$ $233$ $276$

answered Jan 10 in Operating System by swapnilbaviskar10 (55 points) | 622 views

+1 vote

4 answers

16

MadeEasy Test Series: Operating System - Resource Allocation

answered Jan 9 in Operating System by Anup dogrial (299 points) | 115 views

0 votes

4 answers

17

Which of the following is not a necessary condition for a deadlock among processes?

answered Jan 9 in Operating System by Anup dogrial (299 points) | 1.2k views

+6 votes

5 answers

18

ISRO2017-68
A critical region is a piece of code which only one process executes at a time is a region prone to deadlock is a piece of code which only a finite number of processes execute is found only in windows NT operating system

answered Jan 8 in Operating System by Anup dogrial (299 points) | 2.7k views

+1 vote

2 answers

19

GO2019-FLT1-19
A computer system consists of infinitely large primary memory storage capacity. In other words the physical address space exceeds the logical address space significantly in all cases. In such situation which of the following statements regarding virtual ... concept cannot be used in such situation Virtual memory concept can be used to give multiprogramming capability to system

answered Jan 7 in Operating System by JashanArora Loyal (6.1k points) | 219 views

+2 votes

2 answers

20

GO2019-FLT1-12
Consider a parent process $P$ that has forked a child process $C$. $C$ has again forked another child process $D$. Now $P$ terminates while $C$ and $D$ are still running. In this case, which of the following statements is true? $P$ ... becomes a zombie process, until adopted by the parent process of $P$ $P$ immediately becomes an orphan process, until adopted by its parent

answered Jan 7 in Operating System by JashanArora Loyal (6.1k points) | 319 views

+2 votes

1 answer

21

File System - Unix Inode

answered Jan 6 in Operating System by Sahin (361 points) | 264 views

+21 votes

4 answers

22

GATE1998-1.18
Which of the following devices should get higher priority in assigning interrupts? Hard disk Printer Keyboard Floppy disk

answered Jan 6 in Operating System by Anony_XYZ (17 points) | 3.8k views

+49 votes

10 answers

23

GATE2014-2-33
A computer has twenty physical page frames which contain pages numbered $101$ through $120$. Now a program accesses the pages numbered $\text{1, 2, ..., 100}$ in that order, and repeats the access sequence THRICE. Which one of the following ... faults as the optimal page replacement policy for this program? Least-recently-used First-in-first-out Last-in-first-out Most-recently-used

answered Jan 5 in Operating System by swapnilbaviskar10 (55 points) | 8.8k views

+29 votes

4 answers

24

GATE2014-2-32
Three processes $A$, $B$ and $C$ each execute a loop of $100$ iterations. In each iteration of the loop, a process performs a single computation that requires $t_c$ CPU milliseconds and then initiates a single I/O operation that lasts for $t_{io}$ ... a time slice of $50$ milliseconds. The time in milliseconds at which process C would complete its first I/O operation is ___________.

answered Jan 5 in Operating System by swapnilbaviskar10 (55 points) | 3.2k views

0 votes

2 answers

25

UGCNET-NOV2017-III-51
User level threads are threads that are visible to the programmer and are unknown to the kernel. The operating system kernel supports and manages kernel level threads. Three different types of models relate user and kernel level threads. Which of the following statements is/are true ? (a) (i ... is false; (b) is true (3) Both (a) and (b) are true (4) Both (a) and (b) are false

answered Jan 4 in Operating System by Ram Swaroop Loyal (5.3k points) | 218 views

0 votes

2 answers

26

Self Doubt (Semaphores)
struct Semaphore { enum value(0,1); Queue type L; } Down (Semaphore S) { if(S.value==1) { S.value=0; } else { put process(PCB) in S.L; sleep(); } } Up(Semaphore S) { if(S.L is empty) { S.value=1; } else { select a process from S.L; ... and goes to sleep. P0 comes out and exeutes the else part of Up and wakes P1 up. Now how will P1 enter the CS, since S.value is still 0?

answered Jan 3 in Operating System by yadavg123 (81 points) | 190 views

+45 votes

5 answers

27

GATE2006-63, UGCNET-June2012-III-45
A computer system supports $32$-bit virtual addresses as well as $32$-bit physical addresses. Since the virtual address space is of the same size as the physical address space, the operating system designers decide to get rid of ... made more efficient now Hardware support for memory management is no longer needed CPU scheduling can be made more efficient now

answered Jan 2 in Operating System by felics moses 1 (89 points) | 7.2k views

+27 votes

5 answers

28

GATE2004-49
A unix-style I-nodes has $10$ direct pointers and one single, one double and one triple indirect pointers. Disk block size is $1$ Kbyte, disk block address is $32$ bits, and $48$-bit integers are used. What is the maximum possible file size? $2^{24}$ bytes $2^{32}$ bytes $2^{34}$ bytes $2^{48}$ bytes

answered Jan 1 in Operating System by JashanArora Loyal (6.1k points) | 7k views

+33 votes

3 answers

29

GATE2004-11
Consider the following statements with respect to user-level threads and kernel-supported threads context switch is faster with kernel-supported threads for user-level threads, a system call can block the entire process Kernel supported threads can be scheduled independently User level threads are ... III) and (IV) only (II) and (III) only (I) and (III) only (I) and (II) only

answered Jan 1 in Operating System by JashanArora Loyal (6.1k points) | 6.3k views

+6 votes

4 answers

30

Deadlock
A computer system has 6 tape drives with n processes competing for them. Each process may need 3 tape drives. The maximum value of n for which the system is guaranteed to be deadlock free is a) 1 b) 2 c) 3 d)4 Ans given is 2....But for 4 processes ... process...so continuing in this way we can allocate resources to each process without any deadlock...... Plz explain why answer given is b)

answered Dec 31, 2019 in Operating System by JashanArora Loyal (6.1k points) | 6.8k views

+34 votes

3 answers

31

GATE2009-51
A hard disk has $63$ sectors per track, $10$ platters each with $2$ recording surfaces and $1000$ cylinders. The address of a sector is given as a triple $\langle c, h, s \rangle$, where $c$ is the cylinder number, $h$ is the surface number and $s$ is ... $\langle 400, 16, 29 \rangle$ corresponds to sector number: $505035$ $505036$ $505037$ $505038$

answered Dec 30, 2019 in Operating System by shivam001 Junior (959 points) | 6k views

+19 votes

4 answers

32

GATE1998-1.32
A computer has six tape drives, with $n$ processes competing for them. Each process may need two drives. What is the maximum value of $n$ for the system to be deadlock free? $6$ $5$ $4$ $3$

answered Dec 29, 2019 in Operating System by shivam001 Junior (959 points) | 4.5k views

+1 vote

3 answers

33

Andrew S. Tanenbaum (OS) Edition 4 Exercise 4 Question 38 (Page No. 336)
Given a disk-block size of $4\: KB$ and block-pointer address value of $4$ bytes, what is the largest file size (in bytes) that can be accessed using $10$ direct addresses and one indirect block?

answered Dec 27, 2019 in Operating System by shivam001 Junior (959 points) | 52 views

+48 votes

3 answers

34

GATE1999-2.12
Which of the following actions is/are typically not performed by the operating system when switching context from process $A$ to process $B$? Saving current register values and restoring saved register values for process $B$. Changing address translation tables. Swapping out the memory image of process $A$ to the disk. Invalidating the translation look-aside buffer.

answered Dec 26, 2019 in Operating System by chollu (261 points) | 5.3k views

+2 votes

2 answers

35

synchronization
the following five concurrent processes operating on counting semaphore variable (s) which is initialized to 0 P1: wait (s); cs; signal (s); P2: wait (s); cs; signal (s); P3: wait (s); cs; signal (s); P4: signal s); cs; wait (s); P5: signal (s); cs; wait (s); what is the maximum possible value of s? A) 1 B) 2 C) 3 D) 0

answered Dec 21, 2019 in Operating System by SaurabhKatkar (231 points) | 835 views

+1 vote

2 answers

36

Process Synchronisation Of Operating System
Consider the below Algorithm where flag and lock are global variables: P0: P1: while (flag= =1 && lock= = 0); while (flag= = 0 && lock= = 1); Enter CS Enter CS lock= 0 flag= 0 flag= 1 lock= 1 (a) The above algorithm is deadlock free (b) The above algorithm guarantees Mutual Exclusion (c) Both (a) & (b) (d) None of the above

answered Dec 21, 2019 in Operating System by SaurabhKatkar (231 points) | 438 views

0 votes

3 answers

37

What is the type of loading?
Routine is not loaded until it is called.All routine are kept on disk in a relocatable load format.The main program is loaded into memory and is executed.This type of loading is called as _________ A)Static Loading B)Dynamic Loading C)Dynamic Linking D)Overlays Kindly give explanation /attach references if any.

answered Dec 20, 2019 in Operating System by Prateekj9521 (77 points) | 669 views

+4 votes

1 answer

38

TLB and paging
Consider the following piece of code which multiplies two matrices: int a[1024][1024], b[1024][1024], c[1024][1024]; multiply() { unsigned i, j, k; for(i = 0; i < 1024; i++) for(j = 0; j < 1024; j++) for(k = 0; k < ... requires 4 bytes for storage. Compute the number of TLB misses if the page size is 4096 and the TLB has 8 entries with a replacement policy consisting of LRU.

answered Dec 20, 2019 in Operating System by Kevin18051999 (11 points) | 277 views

0 votes

1 answer

39

madeeasy OS 2019- Memory overhead multilevel paging
for memory overhead in Multi level paging, for innermost table only 1 page size shall be counted na? and NOT the complete page table size? please explain the concept, thanks!

answered Dec 19, 2019 in Operating System by rudrap (11 points) | 267 views

0 votes

2 answers

40

Galvin Edition 9 Exercise 9 Question 36 (Page No. 456)
A system provides support for user-level and kernel-level threads. The mapping in this system is one to one (there is a corresponding kernel thread for each user thread). Does a multithreaded process consist of $(a)$ a working set for the entire process or $(b)$ a working set for each thread ? Explain

answered Dec 19, 2019 in Operating System by smsubham Boss (11.4k points) | 76 views

To see more, click for all the questions in this category.

Recent questions and answers in Operating System

50,741 questions

57,251 answers

198,044 comments

104,652 users