109 lines
3.1 KiB
Cheetah
109 lines
3.1 KiB
Cheetah
+----------------------+
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| OS 211 |
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| TASK 1: SCHEDULING |
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| DESIGN DOCUMENT |
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---- GROUP ----
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>> Fill in the names and email addresses of your group members.
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FirstName LastName <email@domain.example>
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FirstName LastName <email@domain.example>
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FirstName LastName <email@domain.example>
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---- PRELIMINARIES ----
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>> If you have any preliminary comments on your submission, or notes for the
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>> markers, please give them here.
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>> Please cite any offline or online sources you consulted while preparing your
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>> submission, other than the PintOS documentation, course text, lecture notes
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>> and course staff.
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PRIORITY SCHEDULING
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===================
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---- DATA STRUCTURES ----
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>> A1: (2 marks)
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>> Copy here the declaration of each new or changed `struct' or `struct' member,
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>> global or static variable, `typedef', or enumeration.
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>> Identify the purpose of each in roughly 25 words.
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>> A2: (4 marks)
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>> Draw a diagram that illustrates a nested donation in your structure and
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>> briefly explain how this works.
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---- ALGORITHMS ----
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>> A3: (3 marks)
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>> How do you ensure that the highest priority waiting thread wakes up first for
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>> a (i) semaphore, (ii) lock, or (iii) condition variable?
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>> A4: (3 marks)
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>> Describe the sequence of events when a call to lock_acquire() causes a
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>> priority donation.
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>> How is nested donation handled?
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>> A5: (3 marks)
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>> Describe the sequence of events when lock_release() is called on a lock that
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>> a higher-priority thread is waiting for.
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---- SYNCHRONIZATION ----
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>> A6: (2 marks)
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>> How do you avoid a race condition in thread_set_priority() when a thread
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>> needs to recompute its effective priority, but the donated priorities
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>> potentially change during the computation?
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>> Can you use a lock to avoid the race?
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---- RATIONALE ----
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>> A7: (3 marks)
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>> Why did you choose this design?
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>> In what ways is it superior to another design you considered?
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ADVANCED SCHEDULER
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==================
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---- DATA STRUCTURES ----
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>> B1: (2 marks)
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>> Copy here the declaration of each new or changed `struct' or `struct' member,
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>> global or static variable, `typedef', or enumeration.
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>> Identify the purpose of each in roughly 25 words.
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---- ALGORITHMS ----
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>> B2: (3 marks)
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>> Suppose threads A, B, and C have nice values 0, 1, and 2 and each has a
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>> recent_cpu value of 0.
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>> Fill in the table below showing the scheduling decision, the priority and the
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>> recent_cpu values for each thread after each given number of timer ticks:
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timer recent_cpu priority thread
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ticks A B C A B C to run
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----- -- -- -- -- -- -- ------
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0
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4
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8
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12
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16
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20
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24
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28
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32
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36
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>> B3: (2 marks)
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>> Did any ambiguities in the scheduler specification make values in the table
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>> uncertain?
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>> If so, what rule did you use to resolve them?
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---- RATIONALE ----
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>> B4: (3 marks)
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>> Briefly critique your design, pointing out advantages and disadvantages in
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>> your design choices.
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