Question
help.
Memory management. For a 32-bit architecture with 512 MB DRAM on the machine. Suppose that the user has opened up 20 active processes, and the size of each page table entry (PTE) is 32-bit. Assume all active processes use the entire virtual address space and the OS uses linear page tables for address translation. For a 4KB page, how much space (in Bytes) is used for all the page tables by the operating system? If now the page size is increased to 64KB, how much space for all the page tables is needed for 64KB pages?
Explanation / Answer
For 64 KB:
offset =log(base 2) 64K = 16 bits
Number of pages = 2^(32-16) = 2^16 = 64 K pages
Memory needed = 64 K table entries x 20 proc x 32 bits/8 = 5 MB
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