Randomized Caches Considered Harmful in Hard Real-Time Systems

Author Jan Reineke

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Jan Reineke
  • Saarland University

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Jan Reineke. Randomized Caches Considered Harmful in Hard Real-Time Systems. In LITES, Volume 1, Issue 1 (2014). Leibniz Transactions on Embedded Systems, Volume 1, Issue 1, pp. 03:1-03:13, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2014)


We investigate the suitability of caches with randomized placement and replacement in the context of hard real-time systems. Such caches have been claimed to drastically reduce the amount of information required by static worst-case execution time (WCET) analysis, and to be an enabler for measurement-based probabilistic timing analysis. We refute these claims and conclude that with prevailing static and measurement-based analysis techniques caches with deterministic placement and least-recently-used replacement are preferable over randomized ones.

Subject Classification

ACM Subject Classification
  • Computer systems organization → Real-time system architecture
  • Theory of computation → Caching and paging algorithms
  • Hardware → Safety critical systems
  • Real-time systems
  • Caches
  • Randomization
  • WCET analysis


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