Copyright © 2008 The Institute of Electronics, Information and Communication Engineers
Regular Section -- Papers -- System Programs |
DAC: A Device-Aware Cache Management Algorithm for Heterogeneous Mobile Storage Systems
1 The author is now with the Department of Computer Science and Engineering, Sun Moon University, Kalsan 100, Tangjeong, Asan, 336–708, Korea., 2 The author is with the School of Computer Science and Engineering, Seoul National University, 599 Gwanangno, Gwanak-gu, Seoul, 151–742, Korea. E-mail: jihong{at}davinci.snu.ac.kr
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Abstract |
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In recent years, heterogeneous devices have been employed frequently in mobile storage systems because a combination of such devices can supply a synergistically useful storage solution by taking advantage of each device. One important design constraint in heterogeneous storage systems is to mitigate I/O performance degradation stemming from the difference between access times of different devices. To this end, there has not been much work to devise proper buffer cache management algorithms. This paper presents a novel buffer cache management algorithm which considers both I/O cost per device and workload patterns in mobile computing systems with a heterogeneous storage pair of a hard disk and a NAND flash memory. In order to minimize the total I/O cost under varying workload patterns, the proposed algorithm employs a dynamic cache partitioning technique over different devices and manages each partition according to request patterns and I/O types along with the temporal locality. Trace-based simulations show that the proposed algorithm reduces the total I/O cost and flash write count significantly over the existing buffer cache algorithms on typical mobile traces.
Key Words: heterogeneous mobile storage, performance optimization, device-aware cache management, dynamic cache partitioning, workload-aware management
Manuscript received January 9, 2008. Manuscript revised July 20, 2008.