CS 3733 Operating Systems, Spring 2005 Midterm 2 Comments

The grade distribution for the second midterm exams was as follows:

• 90-98: 4
• 80-89: 8
• 70-79: 5
• 60-69: 5
• 50-59: 8
• below 50: 15

Comments on particular problems

1. The question asked about the System File Table and only the System File Table.
   Anything else is extraneous.
   Don't say "the entry" when you have not indicated what entry you are referring to.
   When a file is opened, a new entry is created. It does not matter whether a process already has the same file open.
2. Part b) asks about the signal mask of the process, not about other data structures.
3. These are general questions, not specifically about producer-consumer or a case with only two processes.
4. Some people confused C-LOOK with SCAN.
5. This problem does not concern virtual memory. There are no disk accesses.
6. Parts c) and d) should have the same answer. These must be calculated first.