# Recent questions tagged segmentation

1
When segmentation and paging are both being used, as in $MULTICS,$ first the segment descriptor must be looked up, then the page descriptor. Does the $TLB$ also work this way, with two levels of lookup?
2
Explain the difference between internal fragmentation and external fragmentation. Which one occurs in paging systems? Which one occurs in systems using pure segmentation?
3
Suppose that you are measuring the time to receive a segment. When an interrupt occurs, you read out the system clock in milliseconds. When the segment is fully processed, you read out the clock again. You measure 0 msec 270,000 times and 1 msec 730,000 times. How long does it take to receive a segment?
4
For each of the four processes P1,P2,P3, and P4. The total size in kilobytes (KB) and the number of segments are given below. Process Total size (in KB) Number of segments P1 195 6 P2 254 7 P3 45 5 P4 364 4 The page size is 1 KB. The size of an entry in the page table is 4 ... of memory management in the concurrent execution of the above four processes? P < S < T S < P < T S < T < P T < S < P
1 vote
5
Consider a process of 200 KB which has 2 segments each segment size is 256 KB ,Calculate overhead in segmented paging.The page table entry is 4B, segment table entry is 2 B ,Page size is 2KB.
6
The purpose of applying paging in segmentation is A.) To overcome thrashing B.) To overcome external fragmentation C.) To reduce segment table size overhead D.) Both B & C my answer is B given answer is D i want to ask how the size overhead is decreased as compared to pure segmentation.
1 vote
7
Consider a system using segmented paging architecture. The segment is divided into 1K pages and each page is having 512entries. The segment number requires 13 bits to represent all the segments of LAS, and the frame number requires 18 bit to represent all the frame of PAS. The memory ... and page table entry is 4 Word. Then what is the size of each page table? What is the size of all page tables?
1 vote
8
External fragmentation occurs when enough memory space is available but we are not able to allocate that memory space because the memory space available is not contiguous. Now segmentation suffers from external Fragmentation. So how is it non-contiguous memory allocation technique ... can't happen right ? I think each segment can be allocated contiguously only. Please help me with this doubt.
1 vote
9
https://gateoverflow.in/3600/gate2006-it-56 Why is only 1 Page Table considered for 4 Segment Table entries in the selected best answer?
1 vote
10
As we know segmented paging is an improvement over segmentation and paging but I am having some doubts regarding the memory overhead of these three system.It is clear that segmentation need less memory overhead.But about other two system please confirm these two ... conclude that amount of frag mention is much more than pure paging and also extra segmentation table is required in this system?
11
Consider a dynamic partitioning scheme. Show that on an avg. memory contains half as many holes as segments?? i am not able to understand the concept of relation bw holes and segments in context to this question..
1 vote
12
On a system using paging and segmentation references to swapped in locations accessible through an entry in associative table take 200ns if the main memory page table must be used ,the reference takes 400ns.References that results in page faults require 10ms .if the page ... are dirty,what is the effective access time?Assume the system is running only a single process and cpu is idle during swaps.
13
1 vote
14
when and why are segmentation and paging sometimes combined into one scheme?
1 vote
15
Why do we need segmentation and fragmentation both ??? Ultimately both are dividing the message! Please clear my doubt
16
Can someone make me clear whether segmentation method of memory allocation is free from internal and external fragmentation.? Also plz give valid explanation in support of your answer.
17
If there are 32 segments, each size 1 k bytes, then the logical address should have 13 bits 14 bits 15 bits 16 bits
18
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.
19
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
20
explain similarities and dismilarities between Segmented paging and paged segmentation
21
Which of the following problems can be overcome by virtual memory segmentation? a) Segmentation for overlays to deal with lack of physical memory b)Relocation of code and data address can be made segment local c)Protection of access e.g. read , write and execute segments. d) All of these.
1 vote