Speaker: Gang Zhou
Time：8:30 -10:00 am , June 17,2015
Venue：Room 202, Second Floor, Office Building, Software Campus
Host: Xiaohui Yu
Title：Reducing Smartphone Application Delay through Read/Write Isolation
Abstract: The smartphone has become an important part of our daily lives. However, the user experience is still far from being optimal. In particular, despite the rapid hardware upgrades, current smartphones often suffer various unpredictable delays during operation, e.g., when launching an app, leading to poor user experience. In this talk, I will present our investigation on the behavior of reads and writes in smartphones. We conduct the first large-scale measurement study on the Android I/O delay using the data collected from our Android application running on 2611 devices within nine months. Among other factors, we observe that reads experience up to 626% slowdown when blocked by concurrent writes for certain workloads. Additionally, we show the asymmetry of the slowdown of one I/O type due to another, and elaborate the speedup of concurrent I/Os over serial ones. We use this obtained knowledge to design and implement a system prototype called SmartIO that reduces the application delay by prioritizing reads over writes, and grouping them based on assigned priorities. SmartIO issues I/Os with optimized concurrency parameters. The system is implemented on the Android platform and evaluated extensively on several groups of popular applications. The results show that our system reduces launch delays by up to 37.8%, and run-time delays by up to 29.6%.
Bio: Dr. Gang Zhou is an Associate Professor in the Computer Science Department at the College of William and Mary. He received his Ph.D. degree from the University of Virginia in 2007 under Professor John A. Stankovic. He has published over 70 academic papers in prestigious conferences and journals in the areas of ubiquitous computing, mobile computing, sensor networks, and wireless networks. The total citations of his papers are more than 4500 according to 谷歌 Scholar, among which five of them have been transferred into patents and the MobiSys’04 paper has been cited 797 times. Thirteen of his papers have each attracted more than 100 citations since 2004. He is currently serving in the Journal Editorial Board of IEEE Internet of Things as well as Elsevier Computer Networks. He served as technical program vice chair, session chair, member, and doctor colloquium panelist for over 70 academic conferences. He has served as NSF, NIH, and GENI proposal review panelists multiple times since 2008. He received an award for his outstanding service to the IEEE Instrumentation and Measurement Society in 2008. He also won the Best Paper Award of IEEE ICNP 2010, which was given to only one paper from among the 170 papers submitted (acceptance rate: 18%). He received NSF CAREER Award in 2013. He received Plumeri Award for Faculty Excellence at W&M in 2015. He is a Senior Member of ACM and also a Senior Member of IEEE.