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Recent questions tagged virtual-memory

9 votes

4 answers

211

paging
Q. Suppose you have a computer system with a 48-bit logical address, page size of 16KB and 4 bytes per page table entry. If we have a 48MB program such that the entire program and all necessary page tables are in memory. Assume that each page table at diff level fits in a single page.How much memory is used by program, including its page tables?

Akriti sood asked in Operating System Oct 3, 2016

6.8k views

1 vote

3 answers

212

#Operating Systems (Silberschatz, Galvin, Gagne) #VirutalMemory #Page325
In this problem I have a doubt that why effective access time is not taken as effective access time = 1 x 200 + p x (8 milliseconds) because even though pages are accessed after page-fault but all pages must be ... (p x 8 milliseconds) to bring page from disk to memory, plus, 200 nanoseconds for accessing all pages in memory

PratikLatve asked in Operating System Sep 28, 2016

855 views

4 votes

5 answers

213

OS Memory Management
Consider a paging system with page size of 8 KB. If a process of size 34 KB is in logical address space, find the internal fragmentation in Kbytes. a - 4 b- 5 c -6 d -7 Internal fragmentation is always half the page size I guess So the answer should be 4 KB but it is 6 KB How????

bad_engineer asked in Operating System Sep 23, 2016

by bad_engineer

7.4k views

3 votes

1 answer

214

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

579 views

3 votes

1 answer

215

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

316 views

4 votes

2 answers

216

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

978 views

2 votes

3 answers

217

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

850 views

5 votes

1 answer

218

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

639 views

2 votes

1 answer

219

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

458 views

1 vote

2 answers

220

UGC NET CSE | June 2011 | Part 2 | Question: 47
Virtual memory is Related to virtual reality A form of ROM A form of RAM None of the above

makhdoom ghaya asked in Others Aug 30, 2016

by makhdoom ghaya

1.3k views

8 votes

5 answers

221

Size of Virtual Memory - MCQs in CS - Williams
The size of virtual memory is limited by data bus main memory address bus none of the above

Sankaranarayanan P.N asked in Operating System Aug 23, 2016

by Sankaranarayanan P.N

8.5k views

6 votes

1 answer

222

UGC NET CSE | December 2015 | Part 2 | Question: 26
A virtual memory has a page size of $\textsf{1K}$ ... ? $1024, 3072, 4096, 6144$ $1234, 4012, 5000, 6200$ $1020, 3012, 6120, 8100$ $2021, 4050, 5112, 7100$

go_editor asked in Operating System Aug 8, 2016

9.3k views

2 votes

1 answer

223

UGC NET CSE | December 2013 | Part 3 | Question: 70
Translation Look-aside Buffer (TLB) is a cache-memory in which item to be searched is compared one-by-one with the keys a cache-memory in which item to be searched is compared with all the keys simultaneously An associative ... -by-one with the keys An associative memory in which item to be searched is compared with all the keys simultaneously

go_editor asked in Operating System Jul 29, 2016

2.4k views

9 votes

5 answers

224

ISRO2016-22
Let the page fault service time be $10$ ms in a computer with average memory access time being $20$ ns. If one page fault is generated for every $10^6$ memory accesses, what is the effective access time for the memory? 21.4 ns 29.9 ns 23.5 ns 35.1 ns

sourav. asked in Operating System Jul 3, 2016

6.4k views

4 votes

4 answers

225

ISRO2014-70
Dirty bit is used to indicate which of the following? A page fault has occurred A page has corrupted data A page has been modified after being loaded into cache An illegal access of page

go_editor asked in Operating System Jul 1, 2016

5.6k views

4 votes

3 answers

226

ISRO2014-44
A computer has 16 pages of virtual address space but the size of main memory is only four frames. Initially the memory is empty. A program references the virtual pages in the order 0, 2, 4, 5, 2, 4, 3, 11, 2, 10. How many page faults occur if LRU page replacement algorithm is used? 3 5 7 8

go_editor asked in Operating System Jul 1, 2016

4.7k views

0 votes

3 answers

227

UGC NET CSE | June 2014 | Part 2 | Question: 31
In a paged memory management algorithm, the hit ratio is $70$%. If it takes $30$ nanoseconds to search Translation Look-aside Buffer (TLB) and $100$ nanoseconds (ns) to access memory, the effective memory access time is $91$ ns $69$ ns $200$ ns $160$ ns

makhdoom ghaya asked in Operating System Jun 29, 2016

by makhdoom ghaya

8.8k views

6 votes

5 answers

228

ISRO2014-77
What is the size of the physical address space in a paging system which has a page table containing 64 entries of 11 bit each (including valid and invalid bit) and a page size of 512 bytes? $2^{11}$ $2^{15}$ $2^{19}$ $2^{20}$

neha singh asked in Operating System Jun 21, 2016

8.6k views

6 votes

2 answers

229

ISRO2015-31
If there are 32 segments, each size 1 k bytes, then the logical address should have 13 bits 14 bits 15 bits 16 bits

go_editor asked in Operating System Jun 17, 2016

10.8k views

4 votes

1 answer

230

ISRO2008-65
Consider a logical address space of 8 pages of 1024 words mapped into memory of 32 frames. How many bits are there in the logical address? 13 bits 15 bits 14 bits 12 bits

go_editor asked in Operating System Jun 12, 2016

2.5k views

4 votes

3 answers

231

ISRO2007-27
Virtual memory is Part of Main Memory only used for swapping A technique to allow a program, of size more than the size of main memory, to run Part of secondary storage used in program execution None of these

go_editor asked in Operating System Jun 10, 2016

4.1k views

8 votes

4 answers

232

ISRO2011-24
If the page size in a 32-bit machine is 4K bytes then the size of page table is 1 M bytes 2 M bytes 4 M bytes 4 K bytes

jaiganeshcse94 asked in Operating System May 27, 2016

by jaiganeshcse94

22.5k views

1 vote

1 answer

233

Can someone explain this please?
If the size of the logical address space is 2^m and a page size is 2^n addressing units, then the high order m-n bits of the logical address designate the page number and the n low-order bits designate the page offset. Thus, the logical address is as follows: Page Number Page Offset P D m-n n

MohammedSunasra asked in Operating System May 23, 2016

by MohammedSunasra

2.3k views

7 votes

3 answers

234

ISRO2014-35
Using the page table shown below, translate the physical address 25 to virtual address. The address length is 16 bits and page size is 2048 words while the size of the physical memory is four frames. Page Present (1-ln, 0-0ut) Frame 0 1 3 1 1 2 2 1 0 3 0 – 25 6169 2073 4121

Abhi Vs Abhi asked in Operating System May 18, 2016

by Abhi Vs Abhi

6.5k views

83 votes

6 answers

235

GATE CSE 2003 | Question: 79
A processor uses $\text{2-level}$ page tables for virtual to physical address translation. Page tables for both levels are stored in the main memory. Virtual and physical addresses are both $32$ bits wide. The memory is byte addressable. For virtual to physical address translation, ... tables of this process is $\text{8 KB}$ $\text{12 KB}$ $\text{16 KB}$ $\text{20 KB}$

go_editor asked in Operating System Apr 24, 2016

23.8k views

58 votes

4 answers

236

GATE CSE 2013 | Question: 53
A computer uses $46\text{-bit}$ virtual address, $32\text{-bit}$ physical address, and a three-level paged page table organization. The page table base register stores the base address of the first-level table $\text{(T1)},$ which occupies exactly one ... to guarantee that no two synonyms map to different sets in the processor cache of this computer? $2$ $4$ $8$ $16$

go_editor asked in Operating System Apr 21, 2016

30.2k views

32 votes

3 answers

237

GATE CSE 2016 Set 1 | Question: 47
Consider a computer system with $40$-bit virtual addressing and page size of sixteen kilobytes. If the computer system has a one-level page table per process and each page table entry requires $48$ bits, then the size of the per-process page table is __________ megabytes.

Sandeep Singh asked in Operating System Feb 12, 2016

by Sandeep Singh

13.5k views

6 votes

3 answers

238

Memory management and Virtual memory
Which page replacement policy sometimes leads to more page faults when size of memory is increased? A] Optimal B] LRU C] FIFO D] None of these.

Cruise Device asked in Operating System Jan 26, 2016

by Cruise Device

3.5k views

0 votes

1 answer

239

Memory management and Virtual memory
Match the pairs in the following question Pair - 1 A. Virtual Memory B. Shared Memory C. Look-ahead buffer D. Look-aside buffer Pair - 2 P. Temporal locality Q. Spatial locality R. Address translation S. Mutual exclusion

Cruise Device asked in Operating System Jan 26, 2016

by Cruise Device

2.4k views

0 votes

0 answers

240

shivanisrivarshini asked in Operating System Jan 17, 2016

by shivanisrivarshini

856 views

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Recent questions tagged virtual-memory