Homework 2

The following problems will be due in class.

  1. Do problem 5.1 parts b, d, and f from the book.
  2. Do problem 5.2 from the book. Add part c:
    1. When will the aperiodic job mentioned in (b) complete, if the system does do slack stealing?

    When doing parts b and c use the system from previous parts. That is, if any sporadic jobs are scheduled in part a, they will be in the system in parts b and c.

  3. Imagine a digital audio effects processor implemented with three periodic tasks. The input task, Tin samples data at a frequency of 44.1 KHz, and takes 5 μs to execute for each sample. Likewise, the output task, Tout outputs samples at a frequency of 44.1 KHz and takes 6 μs to run. The filter task, Tfilter operates on 64 samples at a time, thus it runs at a frequency 1/64th that of the input and output tasks. The filter takes 500 μs to run.

    A fourth, aperiodic task controls the user interface. The arrival rate of user-interface jobs is 10 jobs/s. The mean execution and mean square execution time 10 ms and 125 ms, respectively.

    What is the average response time of jobs in the aperiodic task? Is the user likely feel that the user-interface is responsive?