CS2200 Summer 2005 Practice Final

Use this test to help you prepare for the final.

Bring a calculator to the final. A powerful calculator.

1. A memory reference is broken down as follows:

        Offset   6 bits
        Index   12 bits
        Tag     14 bits
        
    The cache is a 3-way set associative cache.
    
    It uses a write back policy and an LRU replacement policy.
    
    How much data memory is needed?
    
    Layout the cache in detail
    
    How many total bits are required for the cache?        

2. Define spatial locality, temporal locality and working set. How 
   do cache designs exploit these characteristics of patterns of 
   memory access?
   
3. We have a very complex scientific calculation that takes 9 hours 
   on a supercomputer. We decide to use 4 identical supercomputers 
   but note that only 75% of the work may be parallelized. How long 
   will the program take to run using the 4 supercomputer setup and 
   what speedup does this represent?
   
4. Explain what each of the following do:

    mutex_lock
    
    mutex_unlock
    
    cond_signal
    
    cond_wait
    
    
    
5.  Examine typical producer-consumer code. Construct a possible
    timeline of the execution of this code. At any point in the
    timeline be able to indicate which threads are waiting for
    mutexes and which threads are waiting for condition variables.
    Mark where in time these conditions change.
    
6.  Compare and contrast Repeaters/Hubs, Bridges, Switches, Routers,
    NIC's and Hosts. What layers of the TCP/IP protocol stack are
    used by each device?
    
7.  Suppose a disk drive has 4096 cylinders, numbered from 0 to 
    4095. There are 8 platters and both sides of each are used.
    Each track has 16 sectors. Each sector holds 256 bytes.
    
    How many total bytes on the drive?
        
     
8.  Look up technical information about Inodes and determine the maximum
    file size that can be handled by an Inode.
    
9.  Draw a state diagram which indicates the various states a process
    can be in. Label the diagram to indicate where your P4 accomplished
    each state transition.
    
10. Compare and contrast preemptive and non-preemptive scheduling. Include
    in your answer a discussion of problems such as starvation.
    
11. Given these parameters:

    Wire Band Width = 10Mbps  (107 bits per second),   full-duplex

    Time-of-flight    = 10ms    (10-2 seconds)

    Sender overhead   = 100us   (10-4 seconds)

    Receiver overhead = 100us   (10-4 seconds)

    What's the effective bandwidth if you send 10000-bit messages 
    with acknowledgements.  i.e you can only have one message out on 
    the network at a time.  Acknowlegement messages have a size of 
    100bits.
    
12. How do networks deal with sources of unreliability? Which of these
    did you implement in Project 5.