Optimizing deterministic garbage collection in NAND flash storage systems

Qi Zhang, Xuandong Li, Linzhang Wang, Tian Zhang, Yi Wang, Zili Shao

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

8 Citations (Scopus)

Abstract

NAND flash has been widely adopted as storage devices in real-time embedded systems. However, garbage collection is needed to reclaim space and introduces a lot of time overhead. As the worst system latency is determined by the worst-case execution time of garbage collection in NAND flash, it is important to optimize garbage collection so as to give a deterministic worst system latency. On the other hand, since the garbage collection does not happen very often, optimizing garbage collection should not bring too much overhead to the average system latency. This paper presents for the first time a worst-case and average-case joint optimization scheme for garbage collection in NAND flash. With our scheme, garbage collection can be postponed to the latest stage so improves the average system latency. By combining partial garbage collection and over-provisioning, our scheme can guarantee that one free block is enough to hold all pages from both write requests and valid-page copies. The experiments have been conducted on a real embedded platform and the results show that our technique can improve both worstcase and average-case system latency compared with the previous works.
Original languageEnglish
Title of host publicationProceedings - 21st IEEE Real Time and Embedded Technology and Applications Symposium, RTAS 2015
PublisherIEEE
Pages14-23
Number of pages10
Volume2015-May
ISBN (Electronic)9781479986033
DOIs
Publication statusPublished - 1 Jan 2015
Event21st IEEE Real Time and Embedded Technology and Applications Symposium, RTAS 2015 - Seattle, United States
Duration: 13 Apr 201516 Apr 2015

Conference

Conference21st IEEE Real Time and Embedded Technology and Applications Symposium, RTAS 2015
Country/TerritoryUnited States
CitySeattle
Period13/04/1516/04/15

ASJC Scopus subject areas

  • Engineering(all)

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