Problem 1: Consider a computer system with the following five fixed-sized memory partitions (arranged In that order) and the memory requirements of the given four processes.
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Memory Partitions
|
|
100KB
|
|
400KB
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|
200KB
|
|
400KB
|
|
600KB
|
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Process
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P1
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P2
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P3
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P4
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Memory required
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230 KB
|
370 KB
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190 KB
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595 KB
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a. First-fit technique
b. Best-fit technique
c. Worst-fit technique
d. Which algorithm makes the most efficient use of memory?
Problem 2: The following page table Is for a system with 16-bit virtual and physical addresses and with 4,096-byte pages. The reference bit is set to 1 when the page has been referenced. Periodically. a thread zeroes out all values of the reference bit. A dash for a page frame Indicates the page Is not In memory. The page-replacement algorithm Is localized LRU. and all numbers are provided In decimal.
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Page
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Page Frame
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Reference Bit
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0
|
9
|
0
|
|
1
|
1
|
0
|
|
2
|
14
|
0
|
|
3
|
10
|
0
|
|
4
|
-
|
0
|
|
5
|
13
|
0
|
|
6
|
8
|
0
|
|
7
|
15
|
0
|
|
8
|
0
|
0
|
|
9
|
-
|
0
|
|
10
|
5
|
0
|
|
11
|
4
|
0
|
|
12
|
-
|
o
|
|
13
|
3
|
0
|
|
14
|
-
|
0
|
|
15
|
2
|
0
|
a. Convert the following virtual addresses (in hexadecimal) to the equivalent physical addresses (provide answers in hexadecimal AND decimal). Also set the reference bit for the appropriate entry in the page table. (3)
i. Ox8C2C
ii. Ox00ED
iii. OxEA14
IV. 0x6901
V. Ox23A1 OxA999
b. Using the above addresses as a guide. Provide an example of logical addresses (in hexadecimal) that result in a page faults. (2)
c. From what set of page frames will the LRU page-replacement algorithm choose in resolving a page fault?