Memory

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Which of the following statements are true about page loading strategies?

The loading strategy controls into which frames pages are loaded.

Demand paging can lead to a sequence of page faults when a new program is starting to execute. (correct)

A good loading strategy reduces the number of page faults. (correct)

The loading strategy controls when pages are loaded into frames. (correct)

Which of the following statements are true about logical and physical memory address spaces?

The kernel cannot directly use pointers passed from a user space process to the kernel since such pointers are only meaningful in the logical address space of the user space process. (correct)

A memory management unit translates logical addresses into physical addresses. (correct)

Every process has its own logical address space. (correct)

The kernel translates logical addresses into physical addresses.

Which of the following statements are true about memory mappings?

Memory mappings can be backed by regular files or they can be anonymous. (correct)

Memory mappings can be locked in order to keep stored data secret.

Memory mappings may be shared between processes. (correct)

The POSIX memory mapping API provides programmers a mechanism to add pages to a running process. (correct)

Which of the following statements are true about page faults?

Page faults can be caused by buggy programs. (B), Page faults are detected by the memory management unit. (C), The machine instruction causing a page fault needs to be restarted once the missing page has been loaded into memory. (D) Signup and view all the answers

Which of the following statements are true about paging systems?

Page table entries usually store protection bits (read, write, execute) controling how a CPU can access the content of a page. (A), Paging systems slice variable-length memory segments into fixed-sized pages. (B) Signup and view all the answers

Which of the following statements are true about positioning strategies?

Which of the following statements are true about positioning strategies?

The next fit strategy distributes holes more evenly over the memory space compared to the first fit strategy. (A), Best fit allocates the smallest hole that is just big enough for the request. (B), The buddy system aims at making allocation and deallocation fast at the price of introducing internal fragmentation. (D) Signup and view all the answers

Which of the following statements are true about page replacement strategies?

The first-in-first-out page replacement strategy can suffer from Belady’s anomaly. (A), The least recently used page replacement strategy approximates the optimal algorithm if a program exhibits locality. (C) Signup and view all the answers

Which of the following statements are true about segmentation?

Segmentation requires to load a different base address for each memory segment in the memory management unit. (A), Segmentation leads over time to small memory segments that are mostly unusable. (C), Segmentation leads over time to external fragmentation. (D) Signup and view all the answers

Which of the following statements are true about stack algorithms?

LRU is a stack algorithm. (A), Stack algorithms are defined by associating a sequence of stacks to a reference string. (C), Stack algorithms are a class of page replacement strategies that that do not suffer from Belady’s anomaly. (D) Signup and view all the answers

Which of the following statements are true about swapping?

Swapping moves memory content temporarily to a secondary storage device. (A), Paging systems often apply swapping to individual pages in order to save them while loading other content into their memory frame. (B) Signup and view all the answers

Demand Paging

Loads pages into memory only when needed, leading to a sequence of page faults when a program starts.

Logical and Physical Memory

Kernel cannot use direct pointers from user space because those pointers are only valid in the user's logical space.