Dark Mode

Recent questions tagged least-recently-used

21 votes

4 answers

1

GATE CSE 2023 | Question: 47
Consider the following two-dimensional array $\text{D}$ in the $\text{C}$ programming language, which is stored in row-major order: int D[128][128]; Demand paging is used for allocating memory and each physical page frame holds $512$ elements of the ... j++) D[j][i] *= 10; The number of page faults generated during the execution of this code snippet is _______________.

admin asked in Operating System Feb 15, 2023

by admin

10.4k views

2 votes

1 answer

2

DRDO CSE 2022 Paper 2 | Question: 6
Compute the hit rate and miss/fault rate in least recently used page replacement algorithm for the given reference string with $4$ page frames. String: $7 \; 0 \; 1 \; 2 \; 0 \; 3 \; 4 \; 2 \; 3 \; 0 \; 3 \; 2 \; 1 \; 2 \; 0 \; 1$

admin asked in Operating System Dec 15, 2022

by admin

490 views

0 votes

0 answers

3

William Stallings - Computer Organization and Architecture D
A computer system contains a main memory of 32KB. It also has a 4KB cache divided into four-lines/set with 64B per line. Assume that the cache is initially empty. The processor fetches words from locations 0, 1, 2, . . . ... from the use of the cache. Assume an LRU policy for block replacement. Show the state of cache at the end.

lucifer069 asked in CO and Architecture Sep 15, 2021

305 views

0 votes

2 answers

4

NIELIT 2016 MAR Scientist B - Section C: 38
Determine the number of page faults when references to pages occur in the following 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 $1$ having been brought earlier than page $2$.(LRU algorithm is used). $3$ $5$ $4$ None of these.

admin asked in Operating System Mar 31, 2020

by admin

927 views

1 vote

0 answers

5

Andrew S. Tanenbaum (OS) Edition 4 Exercise 3 Question 31 (Page No. 257)
Give a simple example of a page reference sequence where the first page selected for replacement will be different for the clock and $LRU$ page replacement algorithms. Assume that a process is allocated $3=\text{three}$ frames, and the reference string contains page numbers from the set $0, 1, 2, 3.$

admin asked in Operating System Oct 26, 2019

by admin

348 views

1 vote

4 answers

6

UGC NET CSE | June 2019 | Part 2 | Question: 43
Consider that a process has been allocated $3$ frames and has a sequence of page referencing as $1, 2, 1, 3, 7, 4, 5, 6, 3, 1$. What shall be the difference in page faults for the above string using the algorithms of LRU and optimal page replacement for referencing the string? $2$ $0$ $1$ $3$

Arjun asked in Operating System Jul 2, 2019

by Arjun

4.2k views

0 votes

0 answers

7

ME TEST
A byte addressable computer has a small data cache capable of holding 16 32-bit words. Each cache block consist of four 32 bits words. For the following sequence of main memory addresses (in hexadecimal). The conflict miss if 2-way set associative LRU cache is used is_____ 100,108, 114 ... what will be the address partition look like. 1. tag(7) set(1) offset(4) 2. tag(7) set(1) offset(2)

newdreamz a1-z0 asked in CO and Architecture Jan 21, 2019

by newdreamz a1-z0

382 views

0 votes

0 answers

8

Self doubt
Can anyone explain me the working of NRU & SECOND CHANCE REPLACEMENT ALGORITHM.

Jyoti Kumari97 asked in Operating System Jan 15, 2019

by Jyoti Kumari97

168 views

0 votes

0 answers

9

Gate forum work book
Assume that we have three scenarios l. a fully associative cache, 2. a two way set associative cache and 3. a direct mapped cache. The cache size is 256 bytes. The cache line size is 8 bytes. All variables are 4 bytes. Assume that we have separate instruction and ... many data cache read misses will occur in Two-ay set associative cache? (A)11 (B) 19 (C) 35 (D) None of these

pream sagar asked in CO and Architecture Oct 19, 2018

425 views

3 votes

1 answer

10

LRU page replacement policy
Self doubt: What is the rule or keyb point we should keep in mind while solving problems on LRU page replacement algorithm? Please explain with examples.

Sona Barman asked in Operating System Jan 18, 2018

470 views

6 votes

0 answers

11

OS Galvin - Doubt
Strangely, if we let $S^R$ be the reverse of a reference string S, then the page-fault rate for the OPT algorithm on S is the same as the page-fault rate for the OPT algorithm on $S^R$ . Similarly, the page-fault rate for the LRU algorithm on S is the same as ... time, rather than forward." So, shouldn't it be: page-fault-rate(OPT($S$)) = page-fault-rate(LRU($S^R$)) ???

Rishabh Gupta 2 asked in Operating System Nov 26, 2017

by Rishabh Gupta 2

907 views

1 vote

0 answers

12

Operating Systems Concepts Page fault using LRU
if you have 10 Frames and using LRU how many page fault will be there in both below: for (int j = 0; j < 100; j++) for (int i = 0; i < 100; i++) A[i][j] = A[i][j] + A[j][i]; for (int i = 0; i < 100; i++) for (int j = 0; j < 100; j++) A[i][j] = A[i][j] + A[j][i];

ashu0316 asked in Operating System Nov 13, 2017

392 views

0 votes

1 answer

13

LRU replacement
" In the case of LRU, ( and particularly the stack implementation thereof ), the top N pages of the stack will be the same for all frame set sizes of N or anything larger." Can somebody please explain what this means? Please refer : https://www.cs.uic.edu/~jbell/CourseNotes/OperatingSystems/9_VirtualMemory.html

Warlock lord asked in Operating System Aug 25, 2017

by Warlock lord

399 views

0 votes

0 answers

14

set associative cache

debanjan sarkar asked in CO and Architecture Jan 24, 2017

by debanjan sarkar

314 views

0 votes

1 answer

15

ace operating system
Answer given is B, but I think it should be D. Stack will pop the least recently used page from the top. How can having most recently used page on top help in LRU implementation?

Purple asked in Operating System Nov 29, 2016

by Purple

745 views

0 votes

6 answers

16

UGC NET CSE | August 2016 | Part 2 | Question: 37
Suppose that the virtual Address space has eight pages and physical memory with four page frames. If $LRU$ page replacement algorithm is used, ______ number of page faults occur with the reference string. 0 2 1 3 5 4 6 3 7 4 7 3 3 5 5 3 1 1 1 7 2 3 4 1 $11$ $12$ $10$ $9$

makhdoom ghaya asked in Operating System Sep 28, 2016

by makhdoom ghaya

1.9k views

2 votes

1 answer

17

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

500 views

1 vote

2 answers

18

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

494 views

0 votes

1 answer

19

LRU policy
In LRU policy for cache replacement. the least recently used block is replaced. So, what happens when all the slots are empty at beginning? Is LRU or MRU easier to implement? Why?

Arjun asked in CO and Architecture Jan 11, 2016

by Arjun

608 views

9 votes

3 answers

20

page replacement
An 8 byte, 2-way set associative (using LRU replacement) with 2 byte blocks receives requests for the following addresses (represented in binary): 0110, 0000, 0010, 0001, 0011, 0100, 1001, 0000, 1010, 1111, 0111 . How page replacement is done?What are the types of misses occured in this case?

Sara asked in CO and Architecture Oct 18, 2015

by Sara

3.4k views

To see more, click for the full list of questions or popular tags.

Recent questions tagged least-recently-used