Optimizing storage performance of Android smartphone.

ABSTRACTRecently, mobile platform devices such as smartphone and tablet have spread widely. These devices have embedded NAND flash storage devices. For example, recent smartphones use embedded multimedia cards (eMMC) to store application and data. The performance of smart devices is strongly related with the embedded storage. Recent products of eMMC provide several special features for higher performance. In this paper, we investigated the performance-related features of eMMC device at Android-based smartphone. First, we study the effect of packed command which is introduced at eMMC 4.5 specification. Second, we examine the performance degradation by Least Significant Bit (LSB) backup on MLC eMMC devices. Finally, we observed the performance difference under different ext4 file system configurations such as flex group. From experiments, we found that the storage subsystem of current Android platform needs further optimizations considering the special features of eMMC.