Section: New Results

Probabilistic Real-Time Systems

Participants : Liliana Cucu-Grosjean, Adriana Gogonel, Codé Lo, Dorin Maxim, Cristian Maxim.

The adventof complex hardware, in response to the increasing demand for computing power in next generation systems, exacerbates some of the limitations of static timing analysis for the estimation of the worst-case execution time (WCET) estimation. In particular, the effort of acquiring (1) detail information on the hardware to develop an accurate model of its execution latency as well as (2) knowledge of the timing behaviour of the program in the presence of varying hardware conditions, such as those dependent on the history of previously executed instructions. These problems are also known as the timing analysis walls. The probabilistic timing analysis, a novel approach to the analysis of the timing behaviour of next-generation real-time embedded systems, provides answers to timing analysis walls. In [17] , [48] , [31] timing analysis attacks the timing analysis walls. We have also presented experimental evidence that shows how probabilistic timing analysis reduces the extent of knowledge about the execution platform required to produce probabilistically-safe and tight WCET estimations.

Based on existing estimations of WCET or minimal inter-arrival time, one may propose different probabilistic schedulability analyses [39] . These results were reported in the (PhD thesis of Dorin Maxim , mostly conducted in the Inria TRIO team (before its completion and the move to Aoste in Sept 2013).

2013 was also the year when through several invited talks [26] , [28] , [27] , we had the opportunity to underline historical misunderstandings on probabilistic real-time systems. The most common is related to the notion of independence that is used with a wrong meaning by different papers.