Comp111 - Quiz 2 Review 2 Answers

Quiz 2 Dec 8, 2009 - closed book



Please fill in the blanks. Each blank is worth 5 points.

  1. I/o subsystems form ____producer-consumer____ relationships with one another in order to simplify coding. The disk ____pager/scheduler____ has no idea of the meaning of the data it manages, which can consist of descriptions of inodes, file blocks, and ____directory____ blocks.
  2. An inode for a file contains information on its ____owner____, ____group____, and ____protection/mode____ but contains no information on the files's ____name or path____.
  3. The root directory (/) is the only one whose ____parent____ is itself. We exploit this in determining the ____pathname/name____ of a file, by traversing the directory tree ____upward____ to the root and remembering the name of each ____directory____ encountered.
  4. The virtual memory subsystem utilizes ____disk/swap____ space to augment physical memory. To speed up memory access, a typical VM system ____hashes____ the address of a page.
  5. Round-robin scheduling is optimal for minimizing ____response____ time (in many cases) while ____non-premptive/batch____ scheduling is optimal for maximizing throughput. The scheduler cannot predict when ____blocking/delays____ will occur and has to approximate this based at most upon prior behavior of the process.
  6. One reason that scheduling is not a simple problem is that ____context____ switching does not occur in no time at all. It takes time to save and restore both the values of ____registers____ and the memory ____map____. Some time is saved if the context switch is between ____threads____ rather than between normal processes.