Questions tagged [paging]
Questions about memory-management techniques where the computer manages and transfers data between main memory and secondary storage in pages -- discrete chunks of a fixed size. Operating systems often use paging to implement virtual memory.
83
questions
1
vote
1answer
49 views
Is the term page replacement actually a misnomer?
My understanding is that "page replacement" entails replacing the contents of a frame to bring in a new frame in it's place corresponding to a new page. Since it is not the page, but the frame that ...
2
votes
3answers
79k views
How to work out physical address corresponding to logical address?
I am looking to calculate the physical address corresponding to a logical address in a paging memory management scheme. I just want to make sure I am getting the calculation right, as I fear I could ...
0
votes
3answers
806 views
Operating System Paging concept
I am quoting a paragraph from the book "Operating System Principles" by Galvin.
Usually, each page-table entry is 4 bytes long, but that size can vary as well. A 32-bit entry can point to one of $2^...
-2
votes
1answer
10k views
Calculate the size of Logical and Physical Address
Suppose a logical address space of 32 pages of 2048 words. There are 64 frames in the main memory. According to given information calculate the various parameters related to paging.
Calculate the ...
2
votes
1answer
11k views
Hierarchical Paging
Suppose I have a system with 32-bit logical and 16-bit physical address spaces, and the page size is 512 bytes. For simplicity, ignore the valid/invalid bits in the page table.
How many sections will ...
-2
votes
2answers
262 views
page fault while executing machine instruction
A process executing machine instruction Y right after machine instruction x.On executing x It causes a page fault. what is the next instruction that is executed immediately on restarting the process. ?...
0
votes
2answers
2k views
Compute how much memory is needed for a two level page table
Im studying operating systems and i found an exercise that i cant solve. It asks to compute the memory space needed for a two level page table.
The logical addresses are 32 bit,
Page size is 4KB
...
0
votes
3answers
27k views
Given the logical address, how to extract the page number?
I am studying Computer Systems. I have th following question and its answer:
Given the logical address 0xAEF9 (in hexadecimal) with a page size of
256 bytes, what is the page number?
Answer: ...
3
votes
1answer
10k views
What's the difference between Clock and Second Chance Page-Replacement Algorithm?
I know that they both have reference bit, but I only understand the Second Chance but not the Clock Page-Replacement algorithm.
could anyone help me understand?
1
vote
1answer
19k views
How to calculate virtual address space from page size, virtual address size and page table entry size?
I try to solve an exercise, unfortunately without any success yet.
From the following given information, the virtual address space should be calculated:
Page size is 16 KB
Logical address size is 47 ...
1
vote
2answers
844 views
Question on Virtual memory and Physical memory
This is the question where I'm stuck:
With a 32-bit virtual address, 4 KB pages(12 offset bits), and 4 bytes per page table
entry, we can compute the total page table size:
Number of page table ...
2
votes
1answer
3k views
What are logical addresses and where do they actually reside?
While studying about memory management, paging and segmentation there is a lot of usage of phrases like CPU generates logical addresses and ...
12
votes
2answers
518 views
Are there any garbage collectors that take into account paging?
Garbage collections have to visit all objects that are alive, so as to find the memory that can be reclaimed. (Having many generations’ just delays this a bit)
All things being equal, it is ...
1
vote
1answer
950 views
Processes and Segmentation
The following problem was on my final and in Gate 2006, but I don't understand how to solve it:
Different methods of memory management have different overheads:
...
2
votes
2answers
285 views
Can this question be solved without knowing the Page Table Entry?
I'm preparing for the exams and this question came up -
Consider a machine with $64MB$ physical memory and a $32$-bit virtual address space. If the page size is $4KB$, what is the approximate size ...
12
votes
2answers
10k views
Can someone explain this diagram about Slab Allocation?
I'm trying to understand how Slab Allocation works and why it is different or better than ordinary paging.
I found this diagram which I believe would be helpful if it had more explanation.
Some ...
1
vote
1answer
434 views
In an Inverted Page Table, will following chains happen very often for small addresses?
I just learned about the Inverted Page Table and immediately thought about the chaining model used.
If two processes use the same virtual address, resolving the address will have to include following ...
2
votes
1answer
1k views
Second Chance Page Replacement
In the second chance page replacement algorithm, if a page's reference bit is already set to 1, and the next page in line of the reference string is the same page, does the reference bit stay at 1 or ...
5
votes
1answer
4k views
Page Table Size in a 4 Level Hierarchical Page Table
An Intel 64 bit CPU uses a four-level hierarchical page table. Each of the four levels of the page table can contain 512 entries, and the page table size is 4KB. You should be able to see that it ...
1
vote
0answers
446 views
Clock variant of the Second-Chance page-replacement Algorithm vs. standard Second-Chance Algorithm
A sample question for my upcoming Operating Systems exam is:
Under which circumstances would the clock variant [of the second-chance algorithm] be preferred over the standard second-chance ...
0
votes
1answer
507 views
How does cpu fetch active program data (using virtual address) from storage when there is a page fault?
I read that cpu generates virtual address and using the same mmu translates to physical address and then fetches the data from RAM. But when there is a page fault, the data is fetched from the HDD(or ...
Gilles 'SO- stop being evil'
39.9k7 gold badges106 silver badges170 bronze badges
1
vote
1answer
2k views
Does Second chance Page replacement algorithm suffer with Belady's anomaly?
In Second chance Page replacement algorithm(clock algorithm), if all the Reference bits are set to one, then the algorithm behaves just as FIFO.
Considering this case, can we conclude that Second ...
4
votes
1answer
346 views
Best design of a software controlled page table: to echo the TLB?
I am building some simple system software for the Microblaze FPGA (actually being run on OVPsim at least for now).
The system is to experiment with various memory management regimes.
The first ...
2
votes
0answers
6k views
Effective Acces time in Demand Paging system with Associative memory
Q: Consider a demand-paging system with a paging disk that has an average access and transfer time of 20 milliseconds. Addresses are translated through a page table in main memory, with an access time ...
Gilles 'SO- stop being evil'
39.9k7 gold badges106 silver badges170 bronze badges
0
votes
1answer
1k views
Calculating cache memory based on LRU algorithm
Assuming i have 4 blocks of cache memory, Using the LRU (Least Recently Used)
replacement algorithm on this following sequence of access to memory blocks: 1 2 3 4 5 2 5 4 1 5 2 3 :
...
2
votes
1answer
389 views
Practical Page-Replacement Algorithms
Could anyone suggest other page replacement algorithms that are applicable to the real world aside from
FIFO,
Second Chance (Clock),
Enhanced Second Chance and
Random?
4
votes
1answer
4k views
What is the difference between LRU implemented for a cache and for page replacement?
I have read that true LRU page replacement requires significant hardware support, so only approximation of LRU is implemented for page replacement.
So I wanted to contrast LRU that is implemented for ...
2
votes
1answer
2k views
Maximum amount of memory that can be allocated to a process
DISCLAIMER: The following scenario was taken from an assignment I got in a OS course I'm taking, and it arose a lot of question marks in my head. However non of the questions asked by myself here ...
1
vote
1answer
1k views
Does virtual address space resides in virtual memory?
I have several confusion like :
Does virtual address space resides in virtual memory ?
Does each process has its own virtual address space like each process has its own virtual memory and own page ...
1
vote
0answers
1k views
want to know concept behing Multilevel paging
In order to use large size page table hierarchical paging is done .
In case of two level page table scheme . for :
logical address space - 32bit - $2^32$
page size - 4kb i.e $2^12$
It is mentioned ...
1
vote
1answer
299 views
clarification about Algorithm of page replacement LRU with reference bits
Studying LRU approximation Algorithms I think to have not understand how it works, for example:
...
12
votes
1answer
5k views
Swap space management during pure demand paging
The following is a doubt that I came across while doing a OS home assignment - however, it seems more concept-based than a straightforward coding question, so IMHO I don't think the homework tag is ...
6
votes
1answer
2k views
How to interpret “Windows - Virtual Memory minimum too low” from a CS student point of view?
On my old 256MB RAM, pc I get this message. (I guess it is quite common)
Windows - Virtual Memory minimum too low
Your system is low on virtual memory. Windows is increasing the size of your ...
