V-edge: Fast Self-constructive Power Modeling of Smartphones Based on Battery Voltage Dynamics

System power models are important for power management
and optimization on smartphones. However, existing
approaches for power modeling have several limitations.
Some require external power meters, which is not convenient
for people to use. Other approaches either rely
on the battery current sensing capability, which is not
available on many smartphones, or take a long time to
generate the power model. To overcome these limitations,
we propose a new way of generating power models from
battery voltage dynamics, called V-edge. V-edge is selfconstructive
and does not require current-sensing. Most
importantly, it is fast in model building. Our implementation
supports both component level power models and
per-application energy accounting. Evaluation results using
various benchmarks and applications show that the
V-edge approach achieves high power modeling accuracy,
and is two orders of magnitude faster than existing selfmodeling
approaches requiring no current-sensing.