Operating Systems Question
Q1. Answer al the following questions about paged memory management:(5 pts each) a) How much space needs to be allocated for a single-level page table for a machine with a 32 bit virtual memory address and a 1K page size? (b) Describe two ways in which the page table size requirements could be reduced without changing the address space or page size. Estimate the reduced size for one of these approaches. (c) Given a logical address space of 32 bits, an outer page table and an inner page table of 10 bits where it supports two different page sizes having a page offset of 12 and 22 bits respectively. How many pages are possible if half of the outer page table entries point to the inner page table and half point directly to the larger pages? How many inner page tables are there? d) How much space needs to be allocated n the minimum and maximum cases for a two-level page table for a machine with a 32-bit virtual memory address, a 1K page size, and which has four times as many inner pages as outer pages? Assume any stored page table value requires 32 bits. e For the two-level paging approach above, if a Translation Lookaside Buffer (TLB) is used and can cache both inner and outer page tables, write down the formula for the Effective Access Time (EAT) for a page reference assuming a hit rate of ?, a TLB access time of 60 ns and a memory access time of 200 ns. What must ? be for EAT-280 ns? Assume that either both page tables are in the TLB or neither are Q1. Answer al the following questions about paged memory management:(5 pts each) a) How much space needs to be allocated for a single-level page table for a machine with a 32 bit virtual memory address and a 1K page size? (b) Describe two ways in which the page table size requirements could be reduced without changing the address space or page size. Estimate the reduced size for one of these approaches. (c) Given a logical address space of 32 bits, an outer page table and an inner page table of 10 bits where it supports two different page sizes having a page offset of 12 and 22 bits respectively. How many pages are possible if half of the outer page table entries point to the inner page table and half point directly to the larger pages? How many inner page tables are there? d) How much space needs to be allocated n the minimum and maximum cases for a two-level page table for a machine with a 32-bit virtual memory address, a 1K page size, and which has four times as many inner pages as outer pages? Assume any stored page table value requires 32 bits. e For the two-level paging approach above, if a Translation Lookaside Buffer (TLB) is used and can cache both inner and outer page tables, write down the formula for the Effective Access Time (EAT) for a page reference assuming a hit rate of ?, a TLB access time of 60 ns and a memory access time of 200 ns. What must ? be for EAT-280 ns? Assume that either both page tables are in the TLB or neither are
