What is a Good Buffer Cache Replacement Scheme for Mobile Flash Storage? Hyojun Kim Moonkyung Ryu Umakishore Georgia Institute of Georgia Institute of Ramachandran Technology Technology Georgia Institute of Altanta, GA Altanta, GA Technology
[email protected] [email protected] Altanta, GA
[email protected] ABSTRACT lives. According to a recent Gartner report, within the next Smartphones are becoming ubiquitous and powerful. The three years, mobile platforms will surpass the PC as the most Achilles’ heel in such devices that limits performance is the common web access device worldwide [10]. By 2013, over storage. Low-end flash memory is the storage technology of 40% of the enhanced phone installed-base will be equipped choice in such devices due to energy, size, and cost consid- with advanced browsers [28]. erations. Although mobile systems have become unbelievably pop- In this paper, we take a critical look at the performance of ular today, only few studies have been conducted for deep flash on smartphones for mobile applications. Specifically, understanding of mobile systems. Mobile systems are not we ask the question whether the state-of-the-art buffer cache just miniatures of personal computer systems, and thus, the replacement schemes proposed thus far (both flash-agnostic previous research insights from desktop and server systems and flash-aware ones) are the right ones for mobile flash stor- should not be simply applied to mobile systems without age. To answer this question, we first expose the limitations careful reexamination. For example, a recent study reveals of current buffer cache performance evaluation methods, and that the storage subsystem has a much bigger performance propose a novel evaluation framework that is a hybrid be- effect on application performance on smartphones than it tween trace-driven simulation and real implementation of does on conventional computer systems [21].