Probabilistic WCET estimation in presence of hardware for mitigating the impact of permanent faults - Inria - Institut national de recherche en sciences et technologies du numérique Access content directly
Conference Papers Year : 2016

Probabilistic WCET estimation in presence of hardware for mitigating the impact of permanent faults

Abstract

Fine-grained disabling and reconfiguration of hardware elements (functional units, cache blocks) will become economically necessary to recover from permanent failures, whose rate is expected to increase dramatically in the near future. This fine-grained disabling will lead to degraded performance as compared to a fault-free execution. Until recently, all static worst-case execution time (WCET) estimations methods were assuming fault-free processors, resulting in unsafe estimates in the presence of faults. The first static WCET estimation technique dealing with the presence of permanent faults in instruction caches was proposed in [1]. This study probabilistically quantified the impact of permanent faults on WCET estimates. It demonstrated that the probabilistic WCET (pWCET) estimates of tasks increase rapidly with the probability of faults as compared to fault-free WCET estimates. In this paper, we show that very simple reliability mechanisms allow mitigating the impact of faulty cache blocks on pWCETs. Two mechanisms, that make part of the cache resilient to faults are analyzed. Experiments show that the gain in pWCET for these two mechanisms are on average 48% and 40% as compared to an architecture with no reliability mechanism.
Fichier principal
Vignette du fichier
final.pdf (382.64 Ko) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

hal-01259493 , version 1 (25-03-2016)

Identifiers

  • HAL Id : hal-01259493 , version 1

Cite

Damien Hardy, Isabelle Puaut, Yiannakis Sazeides. Probabilistic WCET estimation in presence of hardware for mitigating the impact of permanent faults. Design, Automation and Test in Europe, Mar 2016, Dresden, Germany. ⟨hal-01259493⟩
180 View
188 Download

Share

Gmail Facebook X LinkedIn More