Given five memory partitions of 100 kb 400 kb 200 kb 300 kb

Question

operating system hw

• What is the difference between external and internal fragmentation?
• Given five memory partitions of 100 KB, 400 KB, 200 KB, 300 KB, and 700 KB (in order), how would each of the first-fit, best-fit, and worst-fit algorithms place processes of 312 KB, 217 KB, 112 KB, and 426 KB
• Consider a computer system with a 32-bit logical address and 2-KB page size. The system supports up to 256 MB of physical memory. How many entries are there in a conventional page table? Explain your answer.
• Consider a paging system with the page table stored in memory.
• If a memory reference takes 120 nanoseconds, how long does a paged memory reference take? Explain your answer.
• 
  If we add TLBs, and 70% of all page-table references are found in the TLBs, what is the effective memory reference time? (Assume that finding a page-table entry in the TLBs takes zero time, if the entry is there.)