os problems

Problems based-on

Topics in Memory Management

Problem 1

Solution 1

Problem 2

0,430

Solution 2

Problem 3

Solution 3

Problem 4

Solution 4

Problem 5

c. Simple paging (assume page size of 2K)

Solution 5(c)

Problem 6

Solution 6

Problem 7

12 bits

Solution 7

Problem 8

Solution 8

Problem 9

Solution 9

Problem 10

Solution 10

memory

Problem 11

Solution 11

Problem 12

Solution 12

Problem 13

Solution 13(a) OPT replacement

(b) FIFO replacement

(c) LRU replacement

Solution 13 …cont’d(d)

Problem 14

Show frame allocation for each of the following replacement policies.

g. With a memory access time of 50 ns what is the EAT in each of the above cases?

f. What are number of frames allocated to the process with a window size of 4, and compute the number of page faults while using the working set model policy.

Solution 14Solution to sections (a), (b), (c), and (d) can be carried out as shown in Solution 13. Solution for section (f) is given below.

EAT = 7/13(50ns + 50ns) + 6/13(50ns + Disk swap + 50ns + 50ns)

Problem 15

Solution 15

Solution 15 …cont’d

Problem 16For a paging system for which PTE size is 32 bytes, page size 1K, and considering a process of size 5MB, compare the page table sizes in terms of number of PTEs, memory needed for the page tables, EAT and TAT using the following paging schemes.• Two level• Three levelAssume memory access time to be 20ns and disk access

time to be 10ms.Assume that the process pages are referenced such that

each of its page is referenced only once. However, the order of reference is not known.

Problem 17 and 18• Considering an TLB of 512 bytes, physical memory of

1MB, PTE of 32 bytes, page size 1K, and a process size of 750K, compute memory needed for the page tables, EAT and TAT for a four-level paging scheme. Assume memory access time to be 10ns and disk access time to be 10ms. Assume that only half of the process pages are referenced twice arbitrarily.

• Compare the performance using the above memory characteristics for page sizes of 2K and 4K respectively and a process of size 500K.