如果你手邊有書的話 9/e page.20 最下面
In a time-sharing system, the OS must ensure reasonable
response time. This goal is sometimes accomplished through
swapping, whereby processes are swapped in and out of main
memory to the disk.
A more common method for ensuring reasonable response time
is virtual memory,a technique that allows the execution of
a process that is not completely in memory. The main
advantage of the virtual-memory scheme is that it enables
users to run programs that are larger than actual physical
memory. Futher, it abstracts main memory into a large,
uniform array of storage, separating logical memory as
view by the user from physical memory.
我記得之前有一題多選題 有一個選項抄這邊前兩三行的
不過他把 response time 改成 turnaround time
結果我還想說是因為swap不能改善時間 然後就看到這段話
所以說為什麼swap或是virtual memory可以改善response??