Midterm Grading Policy:

PART A
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Q1: (Grader: Douglass Davis)

1. (1 point) Correct answers were a and f!

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Q2: (Grader: Douglass Davis)

    2 points each for internal and external fragmentation

1.  for external: not mentioning that there is not enough 
        contiguous space to allocate another process. (-1)
2.  insufficient explanation. (-1)
3.  giving unrelated/incorrect information in explanation. (-1)
4.  switching internal/external definitions (-2)

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Q3: (Grader: Wende Long)

1.  only "pipeline flush", not enough detailed explanation (-1)
2.  Don't save the PC and the current  process state             (-1)
3.  Nothing related to interrupt  vetor or the  handler address (-2)
4.  If there are nothing related to Pipeline processor (-2)
5.  save all the pipeline buffer registers state and don't let some
    instruction to finish, which means that they will resume the
    instruction in the ID , EX stage                               (-2)
6.  Have no idea of the interrupt handling concept   (-4)

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Q4: (Grader: Wende Long)

1. If they not metion the case : pf-rate <L low water mark   (-1)
2. if the instantaneous pf-rate for the current process is high, give it
   more frames or just suspend it and let other process go (-2)
3. give the scheme with working set model     (-2)
4. choose those process  need less memory to run first  (-2) 
5. increase the physical memory                 (-4) 
6. just explain what pf-rate is and it's bad influence with no scheme
   provided                                      (-4)

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Q5: (Grader:  Drew Littlefield)

True/False with no explanation   0 points
True with very bad explanation showing you did not understand VM  1 point
True with good VM explanation    2 points
False, very bad explanation    2 points
False, wrong explanation        3 points
False, correct answer mentioning TLB  5 points

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Q6 (Grader:  Drew Littlefield)

True/False with no explanation  0 points
True with explanation about CPI 1 point
True with above and assuming everything else constant 2 points
False with wrong explanation 3 points
False with good reasoning, but not entirely correct 4 points
False and mentioned clock cycle time or execution time tradeoff 5 points

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Q7: (Grader: Kishore Ramachandran)
  - insufficient explanation (take off 2 points)
  - procedure call/return overhead (take off 3 points)
  - not all registers need be saved (take off 3 points)
  - unrelated explanation (take off 3 points)
  - T/F but no real explanation (take off 4 points)


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PART B
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Q1: (Grader: Namgeun Jeong)
  - Correct calculation of avg CPI  :3 points each
  - Correct way of calculation of cycle time increase : 5 points
  - Correct calculation of cycle time increase : 3~5 points

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Q2: (Grader: He Qi)
  - give 2 points if he gives the expression: effective memory access time
    = hit time*hit rate + miss penalty* miss rate;
  - give 2-5 more points(depending on the degree it's close to the correct
    answer) if he details the above expression in terms of hit time and hit
    rate of L1, L2 and memory;
  - give 3 more points if he placed the correct numbers into the above
    expression;
  - give 5 more points if he solved the equation correctly and gave the
    right answer.

  - give full credit if he gave the correct answer and his work procedure
    was close to complete, even if missing some small details.



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Q3: (Grader: Tianying Chang)

  - Turnaround time P1 correct: give 3 points
  - Turnaround time P2 correct: give 3 points
  - Turnaround time P3 correct: give 3 points
  - If all the three are right, get 10 points

  - Waiting time P1 correct: give 3 points
  - Waiting time P2 correct: give 3 points
  - Waitong time P3 correct: give 3 points
  - Average Waiting time correct: 1 points

  - start time of P2 or P3 incorrect: take off 1 point


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Q4: (Grader: Anand and Steve)

 - Simple replacment policy based on dirty bit and reference bit  (12 points)
	- Correct Pseudocode (5 points)
	- Correct Data Structures (3 points)

 - LRU policies (with reference counting idea) (12 points)
	- Correct Pseudocode (5 points)
	- Correct Data Structures ( 3 points)

 - Second chance algorithm and any others ( 12 points)
	- Pseudocode and Data Structures (8 points)
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