Problem Seven (15 points) Overhead of page fault
A system uses demand paging to implement virtual memory.
Access to physical memory is m = 100 ns. (Access to a page table is assumed to be negligible due to the use of caches and a TLB.)
To process a page fault takes
S = 5 ms if a free page frame is available
S = 15 ms if no free frame is available and thus a resident page needs to be replaced
On average, a free frame is available only 20% of the time.
Determine the maximum page fault rate, P, such that the average memory access time does not exceed 200 ns.