What Matters is an Application: on the Excessive I/Os in Smartphones

Abstract

As the number of mobile phone users are increasing, the importance of understanding its I/O behavior is also increasing. In this paper, after analyzing the basic I/O behavior of fourteen popular smartphone workloads, we chose three applications for deeper analysis. The three applications, Contacts, Web Browser, and Camera, are not only the heaviest I/O generator on Android and Tizen, but also the ones with the highest End-to-End Write Amplification, which is the ratio between the actual volume of data written to the storage and the volume of data user or application intended to create; Contacts Manager, for example, has 1.7 × 105 and 3.9 × 104 on Android and Tizen, respectively. We observed that although background applications, such as spell checker and auto-input-completion are not essential part of using aforementioned applications, but they the critical root of generating heavy I/O overhead on Android devices. We also find that applications keep records of numerous auxiliary information on many different databases and a lot of index tables to enhance the user experience; but some of them are merely a duplicate of same information. The fact that each insert in a table creates ripples of side-effect on index tables and on other related tables, the I/Os are easily amplified and causes heavy overhead on the storage system.