Operating Systems(OSG202)

QN=13 (6948) How many percent of the CPU time is wasted, when a computer system has enough room to hold two program and these programs are idle waiting for I/O half the time?

• 50%

• 25%

• 75%

• None of the other choices

QN=14 (6956) How many ways is Thread implemented?

• 1

• 2

• 3

• None of the other choice

QN=21 (7007) Five batch jobs A through E, arrive at a computer center at almost the same time. They have estimated running times of 8, 6, 2, 10, and 4 minutes. Determine the average waiting time for SJF (Shortest job first) scheduling. Ignore process switching

• 14 minutes

• 8 minutes

• 6 minutes

• 18.8 minutes

QN=26 (7042) One of the most important innovations of demand paging was that it made ____ feasiblea. Memory demandb. Virtual demandc. Virtual pagingd. Virtual memory

• Memory demand

• Virtual demand

• Virtual paging

• Virtual memory.

QN=27 (7048) Which of these statements about the Inverted Page Table are true?

• An entry contains the pair (process, virtual page) mapped into the corresponding page frame

• An entry contains the pair (process, offset) mapped into the corresponding page frame

• An entry contains the pair (segment, virtual page) mapped into the corresponding page frame

• An entry contains the pair (segment, offset) mapped into the corresponding page frame

QN=28 (7057) If there are 64 pages and the page size is 2048 words, what is the length of logical address?

• 14 bits

• 15 bits

• 16 bits

• 17 bits

QN=30 (7072) Which of the following statements is incorrect about Translation Look-aside Buffer (TLB)?

• A TLB is sometimes known as an associative memory

• Each entry of a TLB contains the information about one page, including the virtual page number and the corresponding page frame

• A TLB miss implies a disk operation will follow

• None of the other choices

QN=31 (7080) Working set model is used for:

• Finding the minimum number of frames necessary for a job so that jobs can be run without "thrashing"

• Finding the average number of frames a job will need to run smoothly

• Determining whether page replacement is needed

• All of the other choices

Which is not true about the method of backing store: "Paging to a static swap area"?

• The swap area on the disk is as large as the process virtual address space

• Calculating the address in swap area requires knowing only where the process' paging area begins

• Requires a disk map in memory

• A page that is in memory always have shadow copy on disk

Which of the following statements about segmentation is false?

• There are several linear address spaces

• The total address space can be more than the size of physical memory

• Sharing of procedures between different users can be facilitated

• None of the other choices