Virtual Memory

Question 1

What is the benefit of using sparse addresses in virtual memory?

Question 2

Explain the distinction between a demand-paging system and a paging system with swapping

Question 3

Explain the sequence of events that happens when a page-fault occurs

Question 4

How is the effective access time computed for a demand-paged memory system?

Question 5

Explain how copy-on-write operates

Question 6

Explain the usefulness of a modify bit

Question 7

How does the second-chance algorithm for page replacement differ from the FIFO page replacement algorithm?

Question 8

Explain the distinction between global allocation versus local allocation

Question 9

Why doesn’t a local replacement algorithm solve the problem of thrashing entirely?

Question 10

What are the benefits of using slab allocation to allocate kernel memory?

Question 11

Explain the concept behind prepaging

Question 12

Discuss two strategies for increasing TLB reach

Question 13

How are lock bits useful in I/O requests?

Question 14

Explain how working set model works.

Question 15

T/F - A page fault must be preceded by a TLB miss

Question 16

T/F - The instruction that causes a page fault needs to be re-executed after the fault has been handled.

Question 17

T/F - Stack algorithms can never exhibit Belady’s anomaly.

Answer 17

True
examples of Stack Algorithms: LRU, Optimal Replacement

Question 18

T/F - Some operating systems keep a pool of free frames so that the frequency of page faults is lowered.

Question 19

T/F - Some operating systems provide raw disk, so that special applications can bypass file system when accessing secondary storage.

Question 20

T/F - A reaper starts reclaiming pages as soon as the number of free frames falls below the maximum threshold.

Question 21

T/F - The current best practice to avoid thrashing is to include enough physical memory.

Question 22

T/F - The buddy system for allocating kernel memory is very likely to cause fragmentation within the allocated segments.

Question 23

T/F - In Linux, a slab may only be either full or empty.

Question 24

T/F - Prepaging an executable program is much easier than prepaging a text file.

Question 25

T/F - Solaris uses both a local and global page replacement policy.

Question 26

T/F - Windows uses both a local and global page replacement policy.