I/O Characteristics of Android Applications | Optimization of I/O Characteristics of Android Applications

Prior works performed extensive study of Android I/O characterization and found that a significant fraction of the I/O’s are generated by SQLite operation  found that most I/Os in Android platform are related to SQLite database operations. performed extensive I/O characterization study and found that dominant fraction of Android I/O is synchronous random write caused by misaligned interaction between SQLite and EXT4 file system. We analyzed the I/O behavior of Facebook and Twitter apps, both of which are highly popular smartphone applications. We present the analysis results only for Facebook and Twitter apps because the results are well aligned with our prior study on fourteen popular Android apps and exhibits similar characteristics

The results of the study presented here are based on the Galaxy S3 (Samsung Exynos 4412 1.4 GHz Quadcore,  32 GB eMMC ,2 GB RAM,  Android 4.0.4 with Linux kernel 3.0.15) 4. We use MOST (Mobile Storage Analyzer)  to collect and analyze the I/O trace. Illustrates the results of the analysis. The numbers on the top of each bar represent the number of I/O requests.We briefly summarize our findings as follows:

•  * 90% of the write requests are to the SQLite database.
•  * Of all writes, 70% are synchronous.shows the number of buffered and synchronous
• writes. 70% of all writes are synchronous I/O operations, initiated primarily by SQLite.
• * 75% of all writes are random.  shows the spatial characteristics of the write operations.
• * 64%of the I/O operations involve data with size less than 4 KB. 
• *The interrupt requests issued by the eMMC comprise 18% of all interrupts.