Automatic Monitoring for Interactive Performance and Power Reduction

– Metric: response time. – Automatic, no user program modifications required. – Run-time feedback to the kernel. • Multiprocessing to improve response times. • Slow down processor to save energy when response times are fast enough. Research contributions • A metric (TLP) and a portable methodology for quantifying the amount of concurrency in a multiprocessor system. • An automatic technique for detecting execution episodes that directly impact the user-perceived response times of interactive applications. • Quantifying how much multiprocessing improves the responsiveness of interactive applications. • Faster is not always better. – Fundamental limit to what is perceptible to humans. The time it takes for the computer to respond to user initiated events. The goal is to run fast enough to meet the perception threshold, no point to running any faster.