12 If we add a TLB to the computer in the previous question, and 80 percent of the time the page table
entry is in the TLB (i.e., the required memory access results in a ???hit??? in the TLB 80 percent of the time),
on average, how long does it take to read a word of program memory?
6.13 A paging system uses pages with 1024 addresses per page. Given the following page table:
What are the physical addresses corresponding to the following logical addresses?
Logical address
0
430
2071
4129
5209
6.14 Why do virtual memory systems include a modified bit in the page table entry?
6.15 Why would fixed-length record files be a good choice for storing data from data-base tables?
6.16 How would you expect process scheduling policies to be different on batch computing systems and
interactive systems?
6.17 How would you measure the success of a batch operating system? Would you measure the success of
an interactive system like Unix or Windows the same way? If not, how would you measure the success
of an interactive operating system?
126 OPERATING SYSTEMS [CHAP. 6
Page Frame
0 4
1 10
2 6
3 7
4 5
CHAPTER 7
Networking
INTRODUCTION
If you were to ask someone what invention of the 20th century had the most impact on the way in which
people live their lives, a person might answer by saying, ???computers.
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