Real-Time Systems

, Volume 44, Issue 1–3, pp 1–25 | Cite as

DESH: overhead reduction algorithms for deferrable scheduling

  • Ming Xiong
  • Song HanEmail author
  • Deji Chen
  • Kam-Yiu Lam
  • Shan Feng


Although the deferrable scheduling algorithm for fixed priority transactions (DS-FP) has been shown to be a very effective approach for minimizing real-time update transaction workload, it suffers from its on-line scheduling overhead. In this work, we propose two extensions of DS-FP to minimize the on-line scheduling overhead. The proposed algorithms produce a hyperperiod from DS-FP so that the schedule generated by repeating the hyperperiod infinitely satisfies the temporal validity constraint of the real-time data. The first algorithm, named DEferrable Scheduling with Hyperperiod by Schedule Construction (DESH-SC), searches the DS-FP schedule for a hyperperiod. The second algorithm, named DEferrable Scheduling with Hyperperiod by Schedule Adjustment (DESH-SA), adjusts the DS-FP schedule in an interval to form a hyperperiod. Our experimental results demonstrate that while both DESH-SC and DESH-SA can reduce the scheduling overhead of DS-FP, DESH-SA outperforms DESH-SC by accommodating significantly more update transactions in the system. Moreover, DESH-SA can also achieve near-optimal update workload.


Real-Time databases Temporal validity constraint Fixed priority scheduling Deferrable scheduling 


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Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Ming Xiong
    • 1
  • Song Han
    • 2
    Email author
  • Deji Chen
    • 3
  • Kam-Yiu Lam
    • 4
  • Shan Feng
    • 5
  1. 1.Bell Labs, Alcatel-LucentMurray HillUSA
  2. 2.Department of Computer SciencesUniversity of Texas at AustinAustinUSA
  3. 3.Emerson Process ManagementAustinUSA
  4. 4.Department of Computer ScienceCity University of Hong KongKowloonHong Kong
  5. 5.The Mathematics and Software Science CollegeSichuan Normal UniversityChengduChina

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