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Recent questions tagged go-os-1

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1 answer

1

GATE Overflow | Operating Systems | Test 1 | Question: 30
Match these OS abstractions with Hardware components: A. Thread 1. interrupt B. Virtual address space 2. memory C. File system 3. CPU D. Signal 4. Disk A-2 B-4 C-3 D-1 A-1 B-2 C-3 D-4 A-3 B-2 C-4 D-1 A-4 B-1 C-2 D-3

Bikram asked in Operating System Sep 3, 2016

by Bikram

306 views

3 votes

1 answer

2

GATE Overflow | Operating Systems | Test 1 | Question: 29
Semaphores are used to solve the problem of resource allocation process synchronization deadlock process communication

Bikram asked in Operating System Sep 3, 2016

by Bikram

356 views

3 votes

1 answer

3

GATE Overflow | Operating Systems | Test 1 | Question: 28
Consider a computer with 64 MB physical memory and 32 bit virtual address space. If the page size is 4KB , then the size of page table in MB is _____________ (Assume 2 bits per page table entry for extra information other than that for addressing)

Bikram asked in Operating System Sep 3, 2016

by Bikram

572 views

2 votes

2 answers

4

GATE Overflow | Operating Systems | Test 1 | Question: 27
Dijkstra's Banker's algorithm in Operating System solves the problem of deadlock avoidance recovery from deadlock mutual exclusion context switching

Bikram asked in Operating System Sep 3, 2016

by Bikram

364 views

3 votes

1 answer

5

GATE Overflow | Operating Systems | Test 1 | Question: 26
Swap space in the disk is used to _____ save temporary html pages save process data store the super-block store device drivers

Bikram asked in Operating System Sep 3, 2016

by Bikram

313 views

2 votes

1 answer

6

GATE Overflow | Operating Systems | Test 1 | Question: 25
There is a 4 way set associative cache memory with 8 cache blocks. The main memory consists of 256 blocks and the request for memory blocks is in that order: $0,255,1,4,3,8,133,159,216,129,63,8,48,32,73,92,155 $ Which one of the following memory block will not be in cache if LRU replacement policy is used? 159 8 129 48

Bikram asked in Operating System Sep 3, 2016

by Bikram

490 views

4 votes

2 answers

7

GATE Overflow | Operating Systems | Test 1 | Question: 24
A system with a 2-level paging scheme in which a regular memory access takes 150 nanoseconds(ns) and page faults takes 4 miliseconds(ms). An average instruction takes 100 ns of cpu time and two memory accesses. The TLB hit ... every 100,000 instructions. What is the effective average instruction execution time? 446 ns 1230 ns 830 ns 1050 ns

Bikram asked in Operating System Sep 3, 2016

by Bikram

960 views

0 votes

2 answers

8

GATE Overflow | Operating Systems | Test 1 | Question: 23
Consider an operating system capable of loading and executing a single sequential user process at a time. The disk main scheduling algorithm used is FCFS. If FCFS is replaced by SSTF claimed by the service provider to give 50% ... results, what is the expected improvement in the I/O performance of user programs? 50% 40% 25% no improvement

Bikram asked in Operating System Sep 3, 2016

by Bikram

605 views

0 votes

2 answers

9

GATE Overflow | Operating Systems | Test 1 | Question: 22
On a virtual memory system with FIFO page replacement policy, for an arbitrary page access pattern, increasing the number of page frames in main memory will always decrease the number of page faults always increase the number of page faults sometimes increase the number of page faults do not affect the number of page faults

Bikram asked in Operating System Sep 3, 2016

by Bikram

287 views

0 votes

3 answers

10

GATE Overflow | Operating Systems | Test 1 | Question: 21
Consider $m$ processes sharing the CPU in a round-robin manner. Assume that each process switch takes $p$ seconds. For which value of quantum size $w$, the overhead resulting from process switch is minimized but at the same time each process is guaranteed to get it's ... $w \leq \frac{n- mp}{m+1}$ $w \leq \frac{n- mp}{m+1}$

Bikram asked in Operating System Sep 3, 2016

by Bikram

502 views

1 vote

1 answer

11

GATE Overflow | Operating Systems | Test 1 | Question: 20
An operating system contains 3 user processes each requiring 2 units of resource R. The minimum number of units of R such that no deadlocks will ever arise is ____ (assume no other resource requirement)

Bikram asked in Operating System Sep 3, 2016

by Bikram

239 views

0 votes

2 answers

12

GATE Overflow | Operating Systems | Test 1 | Question: 19
The E_CS() and L_CS() functions to implement critical section of a process are realized using Test-and-Set instruction as stated below: void E_CS(X) { while(Test-and-Set(X); } void L_CS(X) { X=0; } In above code snippet, X is a ... into CS in FIFO order more than 1 process can enter into CS at same time i only i and ii ii and iii iv only

Bikram asked in Operating System Sep 3, 2016

by Bikram

461 views

2 votes

2 answers

13

GATE Overflow | Operating Systems | Test 1 | Question: 18
System calls are usually invoked by using a software interrupt polling an indirect jump a privileged instruction

Bikram asked in Operating System Sep 3, 2016

by Bikram

470 views

0 votes

1 answer

14

GATE Overflow | Operating Systems | Test 1 | Question: 17
Thrashing reduces page I/O decreases the degree of multiprogramming implies excessive page I/O improves system performance

Bikram asked in Operating System Sep 3, 2016

by Bikram

381 views

1 vote

2 answers

15

GATE Overflow | Operating Systems | Test 1 | Question: 16
Determine the number of page faults when references to pages occur in the sequence -$1,2,4,5,2,1,2,4$. Assume that the main memory can accommodate 3 pages and already has pages 1, 2 with page 1 having been brought earlier than page 2 and LRU being the replacement strategy used.

Bikram asked in Operating System Sep 3, 2016

by Bikram

485 views

1 vote

2 answers

16

GATE Overflow | Operating Systems | Test 1 | Question: 15
At a particular time of computation, the value of a counting semaphore is $7$ , then $20$ $P$ operations and 'x' $V$ operations were completed on this semaphore. If the final value of the semaphore is $5$, the value of $x$ should be ____

Bikram asked in Operating System Sep 3, 2016

by Bikram

280 views

1 vote

1 answer

17

GATE Overflow | Operating Systems | Test 1 | Question: 14
Dirty bit is used to show the page with corrupted data wrong page in the memory page that is modified after being loaded into cache memory page that is less frequently accessed

Bikram asked in Operating System Sep 3, 2016

by Bikram

204 views

2 votes

3 answers

18

GATE Overflow | Operating Systems | Test 1 | Question: 13
In a paged memory, the page hit ratio is 0.35. The time required to access a page in secondary memory is 100 ns. The time required to access a page in primary memory is 10 ns. The average time required to access a page is 100 ns 68.0 ns 68.5 ns 78.5 ns

Bikram asked in Operating System Sep 3, 2016

by Bikram

818 views

2 votes

2 answers

19

GATE Overflow | Operating Systems | Test 1 | Question: 12
In a multi-user operating system, 20 requests are made to use a particular resource per hour, on average. The probability that no requests are made in 45 minutes is - $e^-{15}$ $e^{-5}$ $1 - e^{-5}$ $1-e^{-10}$

Bikram asked in Operating System Sep 3, 2016

by Bikram

746 views

2 votes

1 answer

20

GATE Overflow | Operating Systems | Test 1 | Question: 11
Aging is keeping track of the cache contents keeping track of what pages are currently residing in the memory keeping track of how many times a given page is referenced increasing the priority of jobs to ensure termination in a finite time

Bikram asked in Operating System Sep 3, 2016

by Bikram

429 views

1 vote

1 answer

21

GATE Overflow | Operating Systems | Test 1 | Question: 10
A computer system has 4 K word cache organized in a block-set associative manner, with 4 blocks per set, 64 words per block. The number of bits in the SET and WORD fields of the main memory address format is 15, 4 6, 4 7, 2 4, 6

Bikram asked in Operating System Sep 3, 2016

by Bikram

317 views

5 votes

5 answers

22

GATE Overflow | Operating Systems | Test 1 | Question: 9
Each process $P_i$, where $i= 1$ to $9$ is coded as follows repeat P (mutex) {critical section } V (mutex) forever The code for $P_{10}$ is identical except that it uses $V$ (mutex) instead of $P$ (mutex) and vice ... number of processes that can be inside the critical section at any moment if initial value of the semaphore is 1? 1 2 3 none

Bikram asked in Operating System Sep 3, 2016

by Bikram

861 views

3 votes

1 answer

23

GATE Overflow | Operating Systems | Test 1 | Question: 8
Consider a computer with 8 MB of main memory and a 128 KB cache. The cache block size is 4KB and it uses a direct mapping scheme for cache management. Total number of different main memory blocks can map onto a given physical cache block is _______

Bikram asked in Operating System Sep 3, 2016

by Bikram

1.3k views

5 votes

1 answer

24

GATE Overflow | Operating Systems | Test 1 | Question: 7
Which of the following page replacement schemes is the toughest to implement from a hardware point of view? LRU FIFO MRU All have equal complexity

Bikram asked in Operating System Sep 3, 2016

by Bikram

630 views

6 votes

2 answers

25

GATE Overflow | Operating Systems | Test 1 | Question: 6
Consider a system having 'm' resources of the same type. These resources are shared by 3 processes A, B and C, which have peak time demands of 3, 4 and 6. The minimum value of 'm' that ensures that ... never occur given that the combined maximum resource requirement of processes B and C at any time is 8 will be ______.

Bikram asked in Operating System Sep 3, 2016

by Bikram

1.2k views

1 vote

0 answers

26

GATE Overflow | Operating Systems | Test 1 | Question: 5
Two concurrent processes P1 and P2 want to use 2 resources J1 and J2 in a Mutually Exclusive way. Assume that initially J1 and J2 are both free. The programs executed by these two processes are as below : ... deadlock would not occur Mutual Exclusion is guaranteed, deadlock might occur Mutual Exclusion is not guaranteed, deadlock might occur

Bikram asked in Operating System Sep 3, 2016

by Bikram

536 views

1 vote

1 answer

27

GATE Overflow | Operating Systems | Test 1 | Question: 3
Which of the following is true? A re-entrant procedure can only be called a fixed number of times A re-entrant procedure can be called even before the procedure has not returned from it's previous call Re-entrant procedures can not be called recursively none of the above

Bikram asked in Operating System Sep 3, 2016

by Bikram

545 views

2 votes

1 answer

28

GATE Overflow | Operating Systems | Test 1 | Question: 4
The size of the virtual memory in a computer system depends on the size of the data bus main memory address bus RAM

Bikram asked in Operating System Sep 3, 2016

by Bikram

457 views

4 votes

0 answers

29

GATE Overflow | Operating Systems | Test 1 | Question: 2
Consider Peterson's algorithm for Mutual Exclusion between two concurrent processes $w$ and $f$. The program executed by the processeses are shown below: Process w Process f repeat flag[w]=true; turn=f; while(P) do no-operation; Enter critical ... and turn = w flag[f]=true and turn=f flag[w]=true and turn=f flag[w]=true and turn=w

Bikram asked in Operating System Sep 3, 2016

by Bikram

476 views

4 votes

1 answer

30

GATE Overflow | Operating Systems | Test 1 | Question: 1
Overlay is a part of an operating system a specific memory location a single contiguous memory that was used in the olden days for running large programs by swapping overloading the system with many user files

Bikram asked in Operating System Sep 3, 2016

by Bikram

596 views

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