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LRFU: A Spectrum of Policies that Subsumes the Least Recently Used and Least Frequently Used Policies
December 2001 (vol. 50 no. 12)
pp. 1352-1361

Efficient and effective buffering of disk blocks in main memory is critical for better file system performance due to a wide speed gap between main memory and hard disks. In such a buffering system, one of the most important design decisions is the block replacement policy that determines which disk block to replace when the buffer is full. In this paper, we show that there exists a spectrum of block replacement policies that subsumes the two seemingly unrelated and independent Least Recently Used (LRU) and Least Frequently Used (LFU) policies. The spectrum is called the LRFU (Least Recently/Frequently Used) policy and is formed by how much more weight we give to the recent history than to the older history. We also show that there is a spectrum of implementations of the LRFU that again subsumes the LRU and LFU implementations. This spectrum is again dictated by how much weight is given to recent and older histories and the time complexity of the implementations lies between O(1) (the time complexity of LRU) and {\rm O}(\log_2 n) (the time complexity of LFU), where n is the number of blocks in the buffer. Experimental results from trace-driven simulations show that the performance of the LRFU is at least competitive with that of previously known policies for the workloads we considered.

[1] M.J. Bach, The Design of the UNIX Operating System. Prentice Hall, 1990.
[2] E.G. Coffman and P.J. Denning,Operating Systems Theory, Prentice-Hall Inc., Englewood Cliffs, N.J., 1973.
[3] P. Cao, E.W. Felten, and K. Li, “Application-Controlled File Caching Policies,” Proc. Summer 1994 USENIX Conf., pp. 171-182, 1994.
[4] R. Karedla, J.S. Love, and B. Wherry, "Caching Strategies to Improve Disk System Performance," Computer, Mar. 1994, pp. 38-46.
[5] V. Phalke and B. Gopinath, "An Inter-Reference Gap Model for Temporal Locality in Program Behavior," Proc. ACM SIGMETRICS 1995 Conf. Measurement&Modeling of Computer Systems, May 1995.
[6] G. Glass and P. Cao, “Adaptive Page Replacement Based on Memory Reference Behavior,” Proc. 1997 ACM SIGMETRICS Conf., pp. 115-126, 1997
[7] Y. Smaragdakis, S. Kaplan, and P. Wilson, “EELRU: Simple and Effective Adaptive Page Replacement,” Proc. 1999 ACM SIGMETRICS Conf., pp. 122-133, 1999.
[8] H. Chon and D. DeWitt, “An Evaluation of Buffer Management for Relational Database Systems,” Proc. 11th Int'l Conf. Very Large Data Bases, 1985.
[9] C. Faloutsos, R. Ng, and T. Sellis, “Flexible and Adaptable Buffer Management Techniques for Database Management Systems,” IEEE Trans. Computers, vol. 44, no. 4, pp. 546-560, Apr. 1995.
[10] T. Johnson and D. Shasha, "2Q: A Low Overhead High Performance Buffer Management Replacement Algorithm," Proc. 20th Int'l Conf. Very Large Data Bases, VLDB '94, pp. 439-450,Santiago de Chile, Chile, Sept.12-15, 1994.
[11] E.J. O'Neil, P.E. O'Neil, and G. Weikum, "The LRU-k Page Replacement Algorithm for Database Disk Buffering," Proc. 1993 ACM Sigmod Int'l Conf. Management of Data, ACM Press, New York, 1993, pp. 297-306.
[12] J.T. Robinson and M.V. Devarakonda, "Data Cache Management Using Frequency-Based Replacement," Proc. 1990 ACM SIGMETRICS Conf. Measurement&Modeling of Computer Systems, May 1990.
[13] L.A. Belady, “A Study of Replacement Algorithms for Virtual-Storage Computers,” IBM Systems J., vol. 5, no. 2, pp. 78-101, 1966.
[14] R.L. Mattson, J. Gecsei, D.R. Slutz, and I.L. Traiger, “Evaluation Techniques for Storage Hierarchies,” IBM Systems J., vol. 9, no. 2, pp. 78-117, 1970.
[15] W. Effelsberg, "Principles of Database Buffer Management," ACM Trans. Database Systems, Vol.9, No. 4, Dec. 1984, pp. 560-595.
[16] J. Choi, S.H. Noh, S.L. Min, and Y. Cho, “An Implementation Study of a Detection-Based Adaptive Block Replacement Scheme,” Proc. 1999 USENIX Conf., pp. 239-252, 1999.
[17] D. Lee, J. Choi, J.-H. Kim, S.H. Noh, S.L. Min, Y. Cho, and C.S. Kim, “LRFU: A Spectrum of Policies that Subsumes the Least Recently Used and Least Frequently Used Policies,” technical report, School of Computer Science and Eng., Seoul Nat'l Univ., 2001. http://www.ee.binghatom.edu/faculty/phatakhttp:/ /archi.snu.ac.kr/syminlrfutr.ps .
[18] M. Baker, J.H. Hartman, M.D. Kupfer, K.W. Shirriff, and J. Ousterhout, "Measurements of a Distributed File System," Proc. 13th ACM Symp. Operating Systems Principles, pp. 198-211, Oct. 1991.
[19] J.R. Spirn,Program Behavior: Models and Measurement, Operating and programming systems series. New York: Elsevier, 1976.
[20] G.S. Gao, “Performance Analysis of Cache Memories,” J. ACM, vol. 25, no. 3, pp. 378-395, 1978.

Index Terms:
Buffer cache, LFU, LRU, replacement policy, trace-driven simulation
Citation:
D. Lee, J. Choi, J.H. Kim, S.H. Noh, S.L. Min, Y. Cho, C.S. Kim, "LRFU: A Spectrum of Policies that Subsumes the Least Recently Used and Least Frequently Used Policies," IEEE Transactions on Computers, vol. 50, no. 12, pp. 1352-1361, Dec. 2001, doi:10.1109/TC.2001.970573
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