Large pages need to be stored contiguously in main memory. There are several ways to do this: a system can designate a portion of main memory exclusively for large pages, a systemcan rearrange pages in main memory whenever a process requests a large page, or a system can do nothing and deny large-page memory allocation requests whenever necessary.Discuss the pros and cons of each of these three

Question

policies.

Suppose an enterprising programmer modifies theWindows XP virtual memory manager so that it allocates space for all page table entries that a process may need as soon as the process is created.Assume that page table entries cannot be moved to secondary storage and that no page table entries are shared What will be an ideal response?

Answer 1

If a system designates a portion of main memory exclusively for large pages, the first
few large-page requests are guaranteed to be fulfilled. However, there is a high chance that
the space will be unused and therefore wasted. Rearranging pages on disk ensures that main
memory is used efficiently, but this entails a high processing cost and may cause unacceptable
delays.Doing nothing saves memory and incurs no processing overhead cost, but many largepage
requests will be denied, especially after the system has been running for a long time.
21.20 [Section 21.7.1, Memory Organization]AWindows XP TLB entry contains the full 32-
bit virtual address and the 32-bit physical address to which it corresponds.Associative memory
is very expensive. Suggest a space-saving optimization for the TLB.