Why Do We Always Blame The Storage Stack?

Much research effort has been devoted to improving the performance of the I/O stack in mobile devices, but limited time has been spent evaluating mobile application performance from the user’s perspective. In this paper, we try to understand how applications running on the newest devices behave with respect to this metric. We develop a methodology for quantifying user-perceived latency and use it to evaluate four common application benchmarks with I/O stack optimization on two of the latest smartphones. Contrary to our expectation, we find that (i) these applications respond reasonably fast and (ii) the user-perceived latency does not drastically (at most 11:8%) benefit from I/O stack optimizations.