Question 648 – Operating-Systems

Penultimate means in second last working set model.
The set of pages that a process is currently using is called its working set. If the entire working set is in memory, the process will run without causing many faults until it moves into another execution phase (e.g., the next pass of the compiler).
Many paging systems try to keep track of each process’ working set and make sure that it is in memory before letting the process run. This approach is called the working set model.. It is designed to greatly reduce the page fault rate.
Working sets are as below:
9 – {9}
6 – {9,6}
2 – {9,6,2}
3 – {9,6,2,3}
4 – {9,6,2,3,4}
4 – {6,2,3,4}
4 – {2,3,4}
4 – {3,4}
3 – {3,4}
4 – {3,4}
4 – {3,4}
2 – {3,4,2}
5 – {3,4,2,5}
8 – {2,4,5,8}
6 – {2,4,5,8,6}
8 – {2,5,8,6}
5 – {5,8,6}
5 – {5,8,6}
3 – {3,5,8,6}
2 – {2,3,5,8}
3 – {2,3,5}
9 – {2,3,9}
6 – {2,3,9,6}
2 – {3,9,6,2}
7 – {3,9,6,2,7}