Here are some common mistakes and selected answers for homework 6
| Question 10.4) |
| a) with location-addressed memories, this creates a rapid retrieval mechanism |
| b) if such content-addressable memory is available, the search time is one no matter the requested item resides. |
| Question 10.6) |
| you have 32 bit address = 25 |
| Memory size = 128 MB = 227 |
| page size = 8 KB =213 |
| a) the number of pages is the size f memory divided by page size --> 227/213=214 = 16,384 frames |
| b) d must be able to reference up to 8 KB = 213 bit --> d is 13 bits |
| c) 32-13=19 bits |
| Question 10.21) |
| Differences: 1- address translation must be performed dynamically on virtual memory systems whereas addressed ay be directly on real memory systems. 2- Real memory systems tend to be contiguous allocation systems whereas virtual memory systems allocate memory non-contiguously. 3- real memory systems, the entire program and its data tend to be in main memory at once, whereas in virtual memory systems only subset of all a program's page or segments are in main memory at once. |
| Real time systems generally do not employ virtual memory because the wait time due to a page fault or segment fault might cause a process to miss its deadline. |