"ASIDE : SOMETIMES LIFE ISN’T PERFECT Even when you design a beautiful system, sometimes all the corner cases don’t work out exactly as you might like. Take the mkdir example above; one could redesign mkdir to have different semantics, thus making it idempotent (think about how you might do so); howe"
"因此我们的页的大小为 1KB(256x4字节)"
"DESIGN TIP : SEPARATION OF POLICY/MECHANISM In many operating systems, a common design paradigm is to separate high-level policies from their low-level mechanisms. You can think of the mechanism as providing the answer to a how question about a system; for example, how does an operating system perfo"
"You may have noticed this book is free and available online. There is one major reason for this: textbooks are generally too expensive. This book, we hope, represents a new wave of free materials to help those in pursuit of their education, regardless of which part of the world they come from or how"
"More generally, any policy (such as RR) that is fair, i.e., that evenly divides the CPU among active processes on a small time scale, will perform poorly on metrics such as turnaround time. Indeed, this is an inherent trade-off: if you are willing to be unfair, you can run shorter jobs to completion"
"[O11] “John Ousterhout’s Home Page” John Ousterhout Available: http://www.stanford.edu/˜ouster/ The home page of the famous Professor Ousterhout. The two co-authors of this book had the pleasure of taking graduate operating systems from Ousterhout while in graduate school; indeed, this is where the "
"DESIGN TIP: IF 1000 SOLUTIONS EXIST, NO GREAT ONE DOES The fact that so many different algorithms exist to try to minimize external fragmentation is indicative of a stronger underlying truth: there is no one “best” way to solve the problem. Thus, we settle for something reasonable and hope it is goo"
"DESIGN TIP: RAM ISN’T ALWAYS RAM The term random-access memory, or RAM, implies that you can access any part of RAM just as quickly as another. While it is generally good to think of RAM in this way, you can probably see that because of hardware/OS features such as the TLB, accessing a particular pa"