operating system (test series)

Question

Suppose you have a computer system with a 48-bit logical address, page size of 16K and 4 bytes per page table entry. If we have a    48 MB program such that the entire program and all necessary page tables are in memory. How much memory is used by program including its page tables?

Comments

My Confusion...
3 level paging required
and form is :                           10   12   12   14

now my confusion is : whole page table will be in memory or a page of page table.
According to accessing of page tables we access 3 pages of ( 1 level,2level,3level page tables) then memory .

According to storage :
case1 )  if whole page table is stored so size is: 2³⁶ B + 2²⁴ B +  2¹² B + 48MB

case2)  if only 1 page of page table is stored then size : 3pages + process = 3(16KB) + 48 MB

which one is correct ?

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Please help ... it would be gratefull :)

Answer 1

No of pages = (process size) / (page size)

                     = (48 MB) / (16 KB)

                      = 3K

Page Table Size = (no of pages) * page table entry

                          = (3K) * (4B)

                          = 12 KB

Total memory used by the program = (process size) +  (page table size)

                                                         = (48 MB) + (12 KB)

                                                         = 49164 KB