Impact of DM-LRU on WCET: A Static Analysis Approach

Authors Renato Mancuso, Heechul Yun, Isabelle Puaut

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Author Details

Renato Mancuso
  • Boston University, MA, USA
Heechul Yun
  • University of Kansas, Lawrence, KS, USA
Isabelle Puaut
  • University of Rennes 1/IRISA, France


We are especially grateful to Daniel Grund for making his research thesis [Grund, 2012] promptly available to us.

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Renato Mancuso, Heechul Yun, and Isabelle Puaut. Impact of DM-LRU on WCET: A Static Analysis Approach. In 31st Euromicro Conference on Real-Time Systems (ECRTS 2019). Leibniz International Proceedings in Informatics (LIPIcs), Volume 133, pp. 17:1-17:25, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2019)


Cache memories in modern embedded processors are known to improve average memory access performance. Unfortunately, they are also known to represent a major source of unpredictability for hard real-time workload. One of the main limitations of typical caches is that content selection and replacement is entirely performed in hardware. As such, it is hard to control the cache behavior in software to favor caching of blocks that are known to have an impact on an application’s worst-case execution time (WCET). In this paper, we consider a cache replacement policy, namely DM-LRU, that allows system designers to prioritize caching of memory blocks that are known to have an important impact on an application’s WCET. Considering a single-core, single-level cache hierarchy, we describe an abstract interpretation-based timing analysis for DM-LRU. We implement the proposed analysis in a self-contained toolkit and study its qualitative properties on a set of representative benchmarks. Apart from being useful to compute the WCET when DM-LRU or similar policies are used, the proposed analysis can allow designers to perform WCET impact-aware selection of content to be retained in cache.

Subject Classification

ACM Subject Classification
  • Computer systems organization → Real-time systems
  • Theory of computation → Caching and paging algorithms
  • real-time
  • static cache analysis
  • abstract interpretation
  • LRU
  • deterministic memory
  • static cache locking
  • dynamic cache locking
  • cache profiling
  • WCET analysis


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