Recent questions tagged tlb

0 votes

0 answers

1

Self Doubt : Regarding TLB entry for a page not present in memory
If a page is not present in the memory, then its corresponding entry in the page table would have the ‘Present’ bit set as 0 to indicate , the page is not present. Will this entry be considered for caching in TLB? As I understand from above line in Tanenbaum, The entry should not be present in TLB. Is my understanding right?

asked May 9 in Operating System by Mayank0343 (7 points) | 24 views

0 votes

0 answers

2

ISI2017-PCB-B-5(b)
Consider a paging system with the page table stored in memory. If a memory reference takes $200$ nanoseconds, how long does a paged memory reference take? If we add a Translation Lookaside Buffer (TLB) and $75$ percent of all page-table references are ... memory reference time? Assume that finding a page-table entry in the TLB takes $20$ nanoseconds, if the entry is present.

asked Apr 8 in Operating System by akash.dinkar12 Boss (40.7k points) | 36 views

0 votes

0 answers

3

Galvin Edition 9 Exercise 9 Question 15 (Page No. 452)
A simplified view of thread states is $Ready$, $Running$, and $Blocked$,where a thread is either ready and waiting to be scheduled, is running on the processor, or is blocked (for example, waiting for I/O). This is illustrated ... the thread change state if an address reference is resolved in the page table? If so, to what state will it change?

asked Mar 21 in Operating System by akash.dinkar12 Boss (40.7k points) | 22 views

0 votes

0 answers

4

Galvin Edition 9 Exercise 9 Question 14 (Page No. 452)
Assume that a program has just referenced an address in virtual memory. Describe a scenario in which each of the following can occur. (If no such scenario can occur, explain why.) • $TLB$ miss with no page fault • $TLB$ miss and page fault • $TLB$ hit and no page fault • $TLB$ hit and page fault

asked Mar 21 in Operating System by akash.dinkar12 Boss (40.7k points) | 14 views

0 votes

0 answers

5

Caching
Given the following information: TLB hit rate 95%, TLB access time is 1 cycle. cache hit rate 90 %, cache access time is 1 cycle. When TLB and cache both get miss; page fault rate is 1% The TLB access and acache access are ... cycles Access to hard drive requires 50,000 cycles. Compute the average memory access latencies when the cache is physically addresses (in cycles).

asked Mar 10 in CO & Architecture by s_dr_13 (147 points) | 52 views

0 votes

0 answers

6

effective memory access time
A demand paging uses a TLB and a single level page table stored in main memory. The memory access time is 5s. The page fault service time is 25s. If 70% of access is in TLB and of the remaining, 20% is not present in the main memory. The effective memory access time is? Thanks!

asked Jan 27 in Operating System by Abhipsa Mishra (159 points) | 156 views

+1 vote

1 answer

7

TLB hit ration and memory lookup time
Consider a system where TLB lookup time is $25$ ns and memory access time is $200$ ns, respectively. Assuming a virtual address space of $2$ KB, page size of $32$ bytes, and a PTE size of $2$ bytes, what is the minimum TLB hit ratio that results in an average v2p (virtual to physical) translation latency of $185$ ns?

asked Jan 13 in Operating System by dd Veteran (58k points) | 58 views

0 votes

1 answer

8

me test series
A computer system implements a 38 bit virtual address, page size of 16 KB, and 256 entries translation look aside buffer (TLB) organized into 32 sets each having 8 ways. If TLB tag does not store any process id. The minimum length of TLB tag in bits is____

asked Jan 11 in Operating System by newdreamz a1-z0 Active (1.7k points) | 33 views

0 votes

1 answer

9

Os TLB question
How they calculated time for number of levels?

asked Dec 16, 2018 in Operating System by muthu kumar Active (1.6k points) | 117 views

0 votes

0 answers

10

MadeEasy Subject Test 2019: Operating System - Translation Lookaside Buffer
A TLB is a hardware device used for speeding up the conversation from virtual address to physical address. Consider a memory management unit where a memory reference takes 500 nanoseconds; TLB (Translation Look aside Buffer) reference ... EMAT using TLB ==> 640ns EMAT wthout TLB ==> 1000ns how to calculate speed Up.?

asked Dec 13, 2018 in Operating System by jatin khachane 1 Loyal (7.1k points) | 74 views

0 votes

1 answer

11

TLB OS
Why the formula used here is not P(10) + (1-P)(50) = 20 ?; A computer keeps its page tables in memory. The time required to read a word from the page table is 50ns. To reduce this overhead, the computer has a TLB, which holds 32 (virtual page, physical page frame) pairs and can ... : 10ns + (1 - p) 50ns = 20ns p =4/5 = .80 The TLB hit rate has to be 80% for a mean access time of 20ns.

asked Dec 3, 2018 in Operating System by rahuljai (467 points) | 159 views

0 votes

0 answers

12

ace test series
A computer whose processes have 1024 pages in their address spaces keeps its page tables in memory. The overhead required for reading a word from the page table is 500 nsec. To reduce this overhead, the computer has tlb which holds 32 entries and can do look up in 100 nsec. What hit rate is needed to reduce the mean overhead to 200 nsec? can anyone solve this

asked Nov 28, 2018 in Operating System by vijju532 Active (1.1k points) | 85 views

0 votes

0 answers

13

TLB Effective Access Time

asked Nov 28, 2018 in CO & Architecture by Balaji Jegan Loyal (5.4k points) | 275 views

0 votes

1 answer

14

SudoGate Test Series - Virtual Memory
A computer system has TLB access time = 30 ns and the main memory access time is 150 ns and if the miss rate is 20 % the calculate the effective memory access time if 3 level of paging is applied. i am getting 270 ns

asked Nov 5, 2018 in Operating System by Gurdeep Saini Loyal (9.5k points) | 113 views

0 votes

1 answer

15

Virtual Memory
Which of the following is true? A. If the page size increases page fault rate may also increase. B. Multi-level paging optimizes program execution time. C. Dynamic linking increases program execution time.Correct Option D. TLB is a software data structure.

asked Jul 18, 2018 in Operating System by Na462 Loyal (8.7k points) | 128 views

0 votes

0 answers

16

caching and virtual memory
I am having troble with these following questions. Please I need help

asked Apr 19, 2018 in Operating System by Samson Bankole (7 points) | 75 views

+2 votes

0 answers

17

Does every process have its own TLB?
I know that every process has its own page table and but is it the same with TLB? Does every process have its own TLB or there is a master TLB which is used by all the processes?

asked Apr 6, 2018 in Operating System by punkprincess (57 points) | 471 views

+3 votes

1 answer

18

My doubt on TLB and page fault
First read this whole thing what I am writing below: Case 1: If we have to access unit address in memory using TLB and we assume that no page fault occurs then, EMAT=p( T+M )+( 1-p ) (T+M+M) T=TLB access time, M= ... if there page fault occurs then how does the last calculated EMAT here affects the first Estimated memory access time which we have calculated using TLB?

asked Apr 5, 2018 in Operating System by Akash Kumar Roy Junior (547 points) | 323 views

0 votes

0 answers

19

TLB JUST FOR KNOWLEDGE
TLB IS EITHER HARDWARE OR SOFTWARE PLZ EXPLAIN BRIEFLY?????

asked Dec 16, 2017 in CO & Architecture by Sunidhi chauhan Junior (571 points) | 44 views

0 votes

0 answers

20

OS TLB
compute system implement a 36-bit virtual address page size of 16KB and a 256-entry translation look aside buffer organized into 64 sets each having four ways.assume that the TLB tag does not store any process id. the minium length of the TLB tag in bits is?

asked Dec 12, 2017 in Operating System by Akshay Koli 4 Active (1.3k points) | 151 views

+3 votes

1 answer

21

TLB buffer
My doubt is Sorry if its silly. 1. TLB Maps from VA --> PA, so when its accessed ? is it when cpu generates logical address and by hardware it get convert into virtual address and then tlb is looked to convert into physical address. 2. When a ... Virtual address space to physical address space i.e. TLB Stores frequent mapping of pages. So where is actually TLB Stored is it in cache?

asked Nov 26, 2017 in CO & Architecture by Na462 Loyal (8.7k points) | 167 views

+1 vote

2 answers

22

Memory overhead in Multilevel paging with TLB
Consider a computer system using 2-level paging with TLB.The logical address supported is 32 bits.The page table is divided into 512 pages each of size 1K.The memory access time is 100ns and the TLB access time 15ns .Page table entry size at 1st ... page table along with the page of the second level page table for a process? A)6KB B)4KB C)5KB D)12KB

asked Nov 23, 2017 in Operating System by raks8877 (29 points) | 923 views

0 votes

0 answers

23

Effective memory access time
please explain how to understand this problem

asked Nov 20, 2017 in CO & Architecture by Parshu gate Active (5.1k points) | 904 views

+2 votes

2 answers

24

TLB HITS
What is the average memory access time (correct to two decimal places) when you have the following memory hierarchy? Assume that (i) the cache uses physical addresses, (ii) the CPU stalls until the data is delivered, (iii) everything fits into the memory, and (iv) the hardware does the page table walk and updates TLB.

asked Nov 12, 2017 in Databases by Parshu gate Active (5.1k points) | 190 views

+4 votes

1 answer

25

Virtual Memory

asked Oct 25, 2017 in Operating System by Shivam Chauhan Loyal (9.1k points) | 206 views

+3 votes

0 answers

26

Effective memory access time
What has to be the general and final formula for calculating the effective memory access time, taking in consideration the $\alpha$-level page table, TLB hit ratio as $h$, miss ratio as $m$, memory access time as $M$ ... for page fault servicing as $x$? There seems to be so many formulae, each different from each other depending on the question.

asked Aug 18, 2017 in CO & Architecture by habedo007 Active (2.4k points) | 402 views

+1 vote

1 answer

27

Multilevel TLB performance
A computer has a 128-entry $L_1$ TLB, 1024-entry $L_2$ TLB, and uses page size of 4KB. A program reads a 1MB array, one byte at a time from start to end, 10 times. Assuming the TLBs are directly mapped and initially empty, and no other memory is accessed, find TLB hits and misses of both $L_1$ and $L_2$ TLB (array is page aligned).

asked Aug 8, 2017 in Operating System by habedo007 Active (2.4k points) | 295 views

+4 votes

1 answer

28

Self-doubt
Can there ever be a TLB hit and a page fault?

asked Jul 23, 2017 in Operating System by just_bhavana Boss (12.4k points) | 326 views

+1 vote

0 answers

29

tlb segmentation paging
Consider a memory system consists of a single external cache with an access time of 30ns and a hit rate of 0.85, and a main memory with an access time of 80ns. Now we add virtual memory to the system. The TLB is implemented internal to the processor chip and takes ... memory access time of the system with virtual memory?( Marks: 0.00 ) 8ns 30ns 40ns 51ns

asked Jan 17, 2017 in Operating System by Neal Caffery Active (1.2k points) | 333 views

0 votes

2 answers

30

TLB paging
Consider a system with 2-levels of paging and a TLB with hit rate of 95% and TLB access time of 1ns. Find the effective memory access time if there’s a data cache whose hit rate is 85% and cache access time is 1ns, and main memory access time is 100ns. 100ns. 27ns 25ns 30ns 20ns

asked Jan 17, 2017 in Operating System by Neal Caffery Active (1.2k points) | 981 views

tags	tag:apple
author	user:martin
title	title:apple
content	content:apple
exclude	-tag:apple
force match	+apple
views	views:100
score	score:10
answers	answers:2
is accepted	isaccepted:true
is closed	isclosed:true

Recent questions tagged tlb

Recent Posts

Recent Blog Comments