I have attached an image with the problem. Student/my Question Part 1. In questi

Question

I have attached an image with the problem.

Student/my Question Part 1.

In question 5.11.1 it says from hennesey/patterson 5th edition, it says "If pages must be brought in from disk, increment the next largest page number". It is not clear to me what "increment the largest page number" means. The solution in chegg does not explain this and they do not seem to follow any logic. I feel like I understand TLB and Page Table in computer architecture. But, it is not clear to me how "increment the largest page number" determines the virtual to physical page translation when you have to go to disk. In 5.11.1 the first address is 4669 (hex 123D) which is not in the TLB or Page Table. Thus, I have to get VirtualPage #1 from disk, but what is the Physical Page # and how is it determined.

Student/my question Part 2.

I have another problem also. The last virtual address in the sequence is 49225 (hex C049). But, page C is not listed in the Page Table given in the problem. The page table only goes up to B (11) while C is 12. How do I find out the Physical Page # of Virtual Page C when it is not in the Page Table given in the problem?

Thank you for any help you can provide. The question is confusing me...

5.11 As described in Section 5.7, virtual memory uses a page table to track the mapping of virtual addresses to physical addresses. This exercise shows how this table must uLya sociative t be updated as addresses are accessed. The following data constitutes a stream of virtual a dresses as seen on a system Ass me·k B pages a 4 entr and true LRU replacement. If pages must be brought in from disk, increment the next largest page number. 4669,2227,13916, 34587,48870, 12608, 49225 TLB Valid Tag Physical Page Number 1 1112 Page table Valid Physical Page or in Disk 0 Disk 0 Disk 0 Disk Disk 0 Disk 1 12 5.11.1 10 S5.7> Given the address stream shown, and the initial TLB and page table states provided above, show the final state of the system. Also list for each reference if it is a hit in the TLB, a hit in the page table, or a page fault.

Explanation / Answer

5.11.1 Part1

When there is a page fault, which means the virtual memory page is not found in physical memory. So it has to be brought from disk and placed in physical memory.

Physical memory are referred interms of frames.

When a new page has to be brought and placed in physical memory, the next available frame should be selected. This number can be obtained from the page table entries.

If there are any frames that are free, whose number can be obtained from the page table entry by fetching the largest frame number in the page table entry plus one, gives the next available frame that can be used to move the virtual memory page from disk to main memory(physical memory frame).

In the above example, upon page fault, frame number (physical memory ) which will be mapped to the required virtual memory(page) will be 12+1=13.

Thus " Increment next largest number"

Thus for virtual memory page 1 is mapped to frame number 13. This will be updated in page table in the second row.

Part 2:

For all the virtual pages there will be entry for each in the page table. Either with frame number if it is present in main memory or a invalid bit stating its present only in disk and its a page fault. In this case, the next available frame(largest frame number +1) is used to map to the virtual page 12.

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