Charlie Hu Seminar: Energy Debugging in Smartphones
Charlie Hu
Professor, Department of Electrical and Computer Engineering and Computer Science
Purdue University
Energy Debugging in Smartphones
February 20, 2013 | 4:00pm | Elings 1605
Abstract
Despite
the incredible market penetration of smartphones and exponential growth of the
app market, utility of smartphones has been and will remain severely limited by
the battery life. As such, energy has increasingly become the scarcest resource
on smartphones which critically affects user experience. In this talk, I will
start with a first study that characterizes smartphone energy bugs, or ebugs,
broadly defined as an error in the smartphone system (apps, framework, OS,
hardware) that results in unexpected smartphone battery drainage and leads to
significant user frustration.
As
a first step towards taming ebugs, we built the first fine-grained energy
profiler, eprof, that performs energy accounting and hence enables
energy-efficient app development by answering the very question "where was
the energy spent inside the app?". Building eprof in turn requires a
fine-grained, online power model which we have developed that captures the
unique asynchronous power behavior of modern smartphones, which defies the
power models developed in the past decade. Using eprof, we dissected the energy drain of some
of the most popular apps in Google Play and discovered ebugs in popular apps
like Facebook.
While
essential, eprof only provides a semi-automatic tool for energy debugging, as
the developer has to be involved in the iterative profiling/debugging process.
The “holy grail” in energy debugging in smartphones is to develop fully
automatic debugging techniques and tools. Time permitting, I will articulate
the fate of energy bugs in smartphone apps and OSes as a consequence of adopting
aggressive sleeping policies and exposing explicit power control APIs to the developers,
and highlight several automatic ebug detection systems we have developed so
far.
Biography 
Y.
Charlie Hu is a Professor of
Electrical and Computer Engineering and Computer Science (by courtesy) and a
University Faculty Scholar at Purdue University. He received his Ph.D. in
Computer Science from Harvard in 1997, and was a research scientist at Rice University
and a co-founder of the iMimic Networking, Inc. before joining Purdue in 2002. His
research interests lie broadly in distributed systems, operating systems,
computer networking, and wireless networking. Charlie received the NSF CAREER
Award in 2003 and the 2009 Early Career Research Award from Purdue College of
Engineering, was named an ACM Distinguished Member in 2010, and is a co-recipient of
EuroSys 2012 Best Student Paper Award.
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