Quiz on Paging and Memory Allocation

1. Quiz 3 CS 143A

2. 5. In paging, physical memory is divided into pages. • True • False 6. In paging, how many memory accesses are required for each data/instruction access? Assume no TLB. • 1 • 2 • 3 • 4 7. An inverted page table has one entry for each real page of memory. • True • False 8. Segmented paged memory overcomes the internal fragmentation problem of segmented memory. • True • False 9. What happens when the segment number > segment-table length register? • The segment is grown to accommodate the request • Fragmentation • The process is swapped out • Segmentation fault 1. Which dynamic storage allocation strategy produces the largest leftover hole: • First-fit • Best-fit • Worst-fit • None of the above 2. External fragmentation is when not enough memory space exists to satisfy a request due to each allocation being larger than necessary. • True • False 3. An invalid bit means which of the following: • The page is swapped out • The page is not in the process’s logical address space • The page is not in the process’s physical address space • The page has not been allocated 4. If a 32-bit machine has a 4K page size, which of the following are valid sizes (in bits) for the page number, offset of the logical address: • 20, 12 • 22, 10 • 16, 16 • a & c • None of the above

3. Quiz 3 – SOLUTIONS CS 143A

4. 5. In paging, physical memory is divided into pages. • True • False 6. In paging, how many memory accesses are required for each data/instruction access? Assume no TLB. • 1 • 2 • 3 • 4 7. An inverted page table has one entry for each real page of memory. • True • False 8. Segmented paged memory overcomes the internal fragmentation problem of segmented memory. • True • False 9. What happens when the segment number > segment-table length register? • The segment is grown to accommodate the request • Fragmentation • The process is swapped out • Segmentation fault 1. Which dynamic storage allocation strategy produces the largest leftover hole: • First-fit • Best-fit • Worst-fit • None of the above 2. External fragmentation is when not enough memory space exists to satisfy a request due to each allocation being larger than necessary. • True • False 3. An invalid bit means which of the following: • The page is swapped out • The page is not in the process’s logical address space • The page is not in the process’s physical address space • The page has not been allocated 4. If a 32-bit machine has a 4K page size, which of the following are valid sizes (in bits) for the page number, offset of the logical address: • 20, 12 • 22, 10 • 16, 16 • a & c • None of the above