11) Given six memory partitions of 300 KB, 600 KB, 350 KB, 200 KB, 750 KB, and 1
ID: 3533246 • Letter: 1
Question
11) Given six memory partitions of 300 KB, 600 KB, 350 KB, 200 KB, 750 KB, and 125 KB (in order), how would the first-fit, best-fit, and worst-fit algorithms place processes of size 115 KB, 500 KB, 358 KB, 200 KB, and 375 KB (in order)? Rank the algorithms in terms of how efficiently they use memory.
21) The BTV operating system has a 21-bit virtual address, yet on certain embedded devices, it has only a 16-bit physical address. It also has a 2-KB page size. How many entries are there in each of the following?
a) A conventional, single-level page table.
b) An inverted page table.
Explanation / Answer
11)
First fit:
115 KB -> 300KB
500 KB -> 600KB
358 KB -> 750KB
200 KB -> 350KB
375 KB -> 750KB
Best fit:
115 KB -> 125KB
500 KB -> 600KB
358 KB -> 750KB
200 KB -> 200KB
375 KB -> 750KB
Worst fit:
115 KB -> 750KB
500 KB -> 750KB
358 KB -> 600KB
200 KB -> 350KB
375 KB -> Internal fragmentation. waits for 750KB or 600KB memory to get free.
Efficiency
Best fit > First fit > Worst fit
21)
Entries on page table = 2^21 / 2^11
= 2^10 or 1KB entries on the page table
In inverted page table: 2^16 / 2^11
= 2^5 = 32 entries
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.