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# System prepended metadata

title: 第14周

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# 題目
* 林子皓
Which of the following statement is correct?
(A)Hierarchical Paging splits the page table into several smaller tables to reduce entry
(B)Hierarchical Paging can use memory flexibly
\(C)Inverted Page Table can reduce time needed
(D)The size of the Hash table affects the length of the bucket chain
Ans:(D)

(A)entry會增加
(B)他需要連續的記憶體位置
\(C)減少記憶體，增加時間


* 楊秉沅
There is a segment table.Now CPU send two tuples A(3,1600) and B(1,1200).
What are the mapping physical address in memory,Please explain the step.

| limit | base | 
| -------- | -------- | 
|  1000    |3400      |
|2000|5300|
|1400|1300|
|500|500|
|350|4600|

Ans.
A:
Step.1 Segment number mapping table can get (limit,base)=(500,500)
Step.2 Check the 1600 is legal or not.Find that 1600 > 500,So there will have a trap.
B:
Step.1 Segment number mapping table can get (limit,base)=(2000,5300)
Step.2 Check the 1200 is legal or not.Find that 1200 < 2000,So it is legal request.
Step.3 base + offset=5300+1200=6500.

* 王尚鵬
Which of the following statement is correct?
(A) The purpose of using TLB is to slow down the speed of the system in order to reduce work load of it.
(B) In shared Page technique, all the process don’t need to have private code or data, they share all code and data to minimize the storage used.
\(C) Two-Level Page-Table is to solve the problem that when the page table is getting to large, it will waste a lot of time to access data.
(D) Segment-table length register (STLR) indicates number of segments used by a process. When segment number s is greater than STLR, the segment number is legal.
Ans : \(C)
Explain:
(A) Is to speed up the system.
(B) process might have private data or code that can’t shared with other process.
(D) s is legal if s < STLR



* 楊閔恩
What makes the two-level page table impractical in modern computers?

Ans:
In modern 64-bit systems, the reasons why the two-level page table is impractical are as follows:

The memory space required for the page table is too large and must be contiguous. Additionally, multiple memory lookups increase delays, and the more levels added, the more severe the delays become.