Timing analysis research Nutshell: predict how long a computer program will take to execute. I need 2 students this summer Aspects of problem: Hardware issues Software: understanding the structure of a program, like a compiler would Output: Worst case execution time Overall distribution of execution times Maybe it’s unknown because of parameter input?
Why? A real-time system is an OS or entire computer system in which jobs must be completed by some deadline Military Automotive, aviation Factories The OS must schedule jobs on the CPU, to insure efficiency and that jobs meet deadlines. Requires accurate knowledge of program’s execution time.
Benefits to you Gain deeper understanding of: Gain experience with: computer organization features of a programming language how a compiler works operating system scheduling algorithm efficiency Gain experience with: data structures like linked lists, trees breaking a big problem into smaller tasks Getting your work published/presented
Current work Predict the execution time distribution of a simple computer program The WCET may be wildly pessimistic! Sources of variation Input data The probability that an if-condition is true or false Verify results Run the program on Raspberry Pi many times, see if we get a similar distribution Open question: how can we tell if our prediction is good enough? Different metrics are possible.
How do we do it? Timing analyzer: our program, similar to a compiler To determine execution time of entire program, or any part of it Ongoing modification to handle the ARM7 architecture specs. Is our probability formula accurate? Simulation Actually run the program, and compare execution times. To generate meaningful distribution, need to run thousands of times!
Venues Real-Time Systems Symposium Real-Time Technology and Applications Symposium Euromicro Real-Time Systems Conference International Workshop on Worst-Case Execution Time Analysis National Conference on Undergraduate Research IEEE Southeast Conference Consortium for Computing Sciences in Colleges