Using a multi$-$level page table can reduce the physical memory

consumption of page tables by only keeping active PTEs in physical memory. How

many levels of page tables will be needed if the segment tables $($the upper$-$level

page tables$)$ are allowed to be of unlimited size? How many memory references are

needed for address translation if missing in TLB$?$

$5\mathrm{.}18\mathrm{.}3[10]<5\mathrm{.}7>$ Suppose the segments are limite