Midterm

1
Midterm

• This overview is NOT comprehensive!!
• Cover 5,6, and 8.

2
Midterm

• This overview is NOT comprehensive!!
• Cover 5,6, and 8.
• Scheduling Responsible for material up to 5.4
  (Multi-processor scheduling).
• Pay very close attention to homework assignments
  and make sure you understand the question (and
  answer!).
• Need to understand idea of CPU/IO cycles in
  processes.
• Scheduling criteria
• Preemptive/Non-preemptive scheduling.
• Know how to use a Gantt chart and how to
  determine things such as turn-around time,
  throughput, etc.

3

• Need to understand all of the scheduling
  algorithms discussed.
• Understand the relationship between context
  switching time and the time slice allocated to
  the processes.

4
Synchronization

• Material up to section 6.7 (Monitors)
• Pay very close attention to the homework
  problems.
• Need to understand race conditions (what they are
  and how they can occur).
• Understand the critical section problem.
• Understand the use of synchronization hardware,
  and how the TestandSet instruction can be used to
  enforce access to critical sections.

5
Use the TestandSet Instruction to enforce mutual
exclusion of the critical sections. Shared int
lock 0
P0 P1 while (1) while (1) ltCritical
Sectiongt ltCritical Sectiongt
6
Semaphores

• You need to understand semaphores.
• How they are used to enforce critical sections.
• How they can provide process synchronization.
• How they can deadlock.
• How they are implemented.
• Precisely what the wait() and signal() routines
  are doing.
• How they can be used in the Bounded Buffer and
  Dining Philosophers problems.
• You really need to understand semaphores!!!

7
Memory Management

• Up to Section 8.6 (Segmentation).
• Pay very close attention to any homework problems
  assigned.
• Need to understand the background information.
• You really need to understand paging!!!

8

• Understand the process of converting a logical
  address to a physical address.
• E.g., here is a processes page table. Pages are
  1K. Assume the CPU outputs logical address 2044.
  What is the physical address?
• Understand how paging works!!!
• Understand what a Translation Look-aside buffer
  is, what it does, and how it works in an address
  translation.

9

• How pages are shared in a paging system.
• How page tables are structured.
• Talked about normal page tables, as well as
  hierarchical, hashed, and inverted page tables.
• Why are these needed?
• How do they work?