Q4. Consider a system that uses pure demand paging. (10 pts) When a process first starts executing, how would you characterize the page fault rate? Once the working set for the process is loaded into memory, how would you characterize the page fault rate? Assume that a process changes its locality and the size of the new working set is too large in available free memory. Identify some options system designers could choose from to handle this situation.

At the first can be stage of execution, page fault rate is has equal number of page fault rate that is occurred in the page and which is divided by the number of instructions carried out.

Secondly, when an entire working system is added, the page fault can only take place when the required number of pages to execute the process cannot be included or added into the physical memory.

When a Virtual memory is used, the space on the logical memory will be bigger than that of the primary memory, and so a part of the program that is not used presently by a process will remain in the secondary memory.

Explanation:

(A) At first when a process starts an execution or implementation, we can categorize the page fault rate has the same the number of fault that is occurred in the page which is divided by the number of executed instructions.

So the more number of instructions available per page, the lower rate of page faults.

(B) When the whole number of pages is loaded, the page fault can only happen only when the needed number of pages to carry on the process cannot be accommodate into the physical memory all at once.

(C) Another way is to apply the virtual memory, where the logical memory space is larger or bigger than the primary memory and so, part of the program that is not used currently by process that stays in the secondary memory, so with regards to the demand, the pages from the secondary memory can be taken to the primary memory.