Tunable WCET for hard real-time multicore system

Yoon, Man-Ki

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https://hdl.handle.net/2142/24171 Copy

Description

Title

Tunable WCET for hard real-time multicore system

Author(s)

Yoon, Man-Ki

Issue Date

2011-05-25T15:00:21Z

Director of Research (if dissertation) or Advisor (if thesis)

Sha, Lui R.

Department of Study

Computer Science

Discipline

Computer Science

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Hard real-time multicore system
• Worst-case execution time
• Tunable Worst-Case Execution Time (WCET)
• Harmonic round-robin arbitration

Abstract

In recent years, multicore processors have been receiving a significant amount of attention from avionic and automotive industries as the demand for high-end real-time applications drastically increases. However, the unpredictable worst-case timing behavior that mainly arises from shared resource contention in current multicore architectures has been the biggest stumbling block for a widespread use of multicores in hard real-time systems. A great deal of research efforts have been devoted to address the issue. Among others, the development of a new multicore architecture has emerged as an attractive solution because it is possible to eliminate the sources of unpredictable interferences in the first place, or at least to turn them into predictable ones. Accordingly, this opens a new possibility of system-level optimizations with multicore-based hard real-time systems. To address this issue, this study proposes a new perspective of WCET model called tunable WCET, in which the WCET of a task is partitioned into fixed execution time and tunable delay. Our tunable WCET model enables WCET-aware shared resource allocation/arbitration by elastically deforming the tunable delays of tasks. For this, we also propose novel shared bus arbitration and cache partitioning methods called harmonic round-robin bus scheduling and two-level cache partitioning. We present a mixed integer linear programming (MILP) formulation as the solution to the optimization problem of tunable WCETs. Our experimental results show that the proposed methods can significantly lower overall system utilization.

Graduation Semester

2011-05

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http://hdl.handle.net/2142/24171

Copyright and License Information

Copyright 2011 Man Ki Yoon

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