Providing sustainable performance in thermally constrained mobile devices

State-of-the-art smartphones can generate excessive amounts of heat during high computational activity or long durations of use. While throttling mechanisms ensure safe component and outer skin level temperatures, frequent throttling can largely degrade the user-perceived performance. This work explores the impact of multiple different thermal constraints in a real-life smartphone on user experience. In addition to high processor temperatures, which have traditionally been a major point of interest, we show that applications can also quickly elevate battery and device skin temperatures to critical levels. We introduce and evaluate various thermally-efficient runtime management techniques that slow down heating under performance guarantees so as to sustain a desirable performance for maximum durations. Our techniques achieve up to 8x longer sustainable QoS.