A Study on Demand Paging For NAND Flash Memory Storages

NAND 플래시 메모리 저장장치를 위한 요구 페이징 기법 연구

  • 유윤석 (명지대학교 컴퓨터소프트웨어학과) ;
  • 류연승 (명지대학교 컴퓨터소프트웨어학과)
  • Published : 2007.05.30

Abstract

We study the page replacement algorithms for demand paging, called CFLRU/C, CFLRU/E and DL-CFLRU/E, that reduce the number of erase operations and improve the wear-leveling degree of flash memory. Under the CFLRU/C and CFLRU/E algorithms, the victim page is the least recently used dean page within the pre-specified window. However, when there is not any dean page within the window, the CFLRU/C evicts the dirty page with the lowest frequency while the CFLRU/E evicts the dirty page with the highest number of erase operations. The DL-CFLRU/E algorithm maintains two page lists called the dean page list and the dirty page list, and first finds the page within the dean page list when it selects a victim. However, when it can not find any dean page within the dean page list, it evicts the dirty page with the highest number of erase operations within the window of the dirty page list. In this thesis, we show through simulation that the proposed schemes reduce the number of erase operations and improve the wear-leveling than the existing schemes like LRU.