Use of Measurements in Worst-Case Execution Time Estimation for Real-Time Systems

2021 ◽  
Author(s):  
Jessica Junia Santillo Costa ◽  
Romulo Silva de Oliveira ◽  
Luis Fernando Arcaro
Keyword(s):  
Real Time ◽  
Execution Time ◽  
Time Estimation ◽  
Real Time Systems ◽  
Worst Case ◽  
Worst Case Execution Time ◽  
Time Systems

scholarly journals Worst-case execution-time analysis for embedded real-time systems

2003 ◽  
Vol 4 (4) ◽  
pp. 437-455 ◽  
Author(s):  
Jakob Engblom ◽  
Andreas Ermedahl ◽  
Mikael Sjödin ◽  
Jan Gustafsson ◽  
Hans Hansson
Keyword(s):  
Real Time ◽  
Execution Time ◽  
Real Time Systems ◽  
Time Analysis ◽  
Worst Case ◽  
Worst Case Execution Time ◽  
Time Systems

An Overview of Worst-Case Execution Time Estimation for Embedded Programs

2014 ◽  
Vol 651-653 ◽  
pp. 624-629
Author(s):  
Liang Liang Kong ◽  
Lin Xiang Shi ◽  
Lin Chen
Keyword(s):  
Embedded Systems ◽  
Real Time ◽  
Execution Time ◽  
Time Estimation ◽  
Worst Case ◽  
Performance Metric ◽  
Worst Case Execution Time ◽  
Hard Real Time ◽  
Time Systems

Most embedded systems are real-time systems, so real-time is an important performance metric for embedded systems. The worst-case execution time (WCET) estimation for embedded programs could satisfy the requirement of hard real-time evaluation, so it is widely used in embedded systems evaluation. Based on sufficient survey on the progress of WCET estimation around the world, it proposes a new classification of WCET estimation. After introducing the principle of WCET estimation, it mainly demonstrates various types of technologies to estimate WCET and classifies them into two main streams, namely, static and dynamic WCET estimations. Finally, it shows the development of WCET analysis tools.

Reconfiguration of Uniprocessor Sporadic Real-Time Systems

2011 ◽  
pp. 167-189 ◽  
Author(s):  
Laurent George ◽  
Pierre Courbin
Keyword(s):  
Sensitivity Analysis ◽  
Real Time ◽  
Performance Tuning ◽  
Real Time Systems ◽  
Software Faults ◽  
Worst Case ◽  
Task Model ◽  
Worst Case Execution Time ◽  
On Line ◽  
Time Systems

In this chapter the authors focus on the problem of reconfiguring embedded real-time systems. Such reconfiguration can be decided either off-line to determine if a given application can be run on a different platform, while preserving the timeliness constraints imposed by the application, or on-line, where a reconfiguration should be done to adapt the system to the context of execution or to handle hardware or software faults. The task model considered in this chapter is the classical sporadic task model defined by a Worst Case Execution Time (WCET), a minimum inter-arrival time (also denoted the minimum Period) and a late termination deadline. The authors consider two preemptive scheduling strategies: Fixed Priority highest priority first (FP) and Earliest Deadline First (EDF). They propose a sensitivity analysis to handle reconfiguration issues. Sensitivity analysis aims at determining acceptable deviations from the specifications of a problem due to evolutions in system characteristics (reconfiguration or performance tuning). They present a state of the art for sensitivity analysis in the case of WCETs, Periods and Deadlines reconfigurations and study to what extent sensitivity analysis can be used to decide on the possibility of reconfiguring a system.

Interactive WCET Prediction with Warning for Timeout Risk

2017 ◽  
Vol 31 (05) ◽  
pp. 1750012 ◽  
Author(s):  
Fanqi Meng ◽  
Xiaohong Su ◽  
Zhaoyang Qu
Keyword(s):  
Execution Time ◽  
Control Flow ◽  
Real Time Systems ◽  
Wcet Analysis ◽  
Running Speed ◽  
Worst Case ◽  
Worst Case Execution Time ◽  
Level Model ◽  
Hard Real Time ◽  
Time Systems

Worst case execution time (WCET) analysis is essential for exposing timeliness defects when developing hard real-time systems. However, it is too late to fix timeliness defects cheaply since developers generally perform WCET analysis in a final verification phase. To help developers quickly identify real timeliness defects in an early programming phase, a novel interactive WCET prediction with warning for timeout risk is proposed. The novelty is that the approach not only fast estimates WCET based on a control flow tree (CFT), but also assesses the estimated WCET with a trusted level by a lightweight false path analysis. According to the trusted levels, corresponding warnings will be triggered once the estimated WCET exceeds a preset safe threshold. Hence developers can identify real timeliness defects more timely and efficiently. To this end, we first analyze the reasons of the overestimation of CFT-based WCET calculation; then we propose a trusted level model of timeout risks; for recognizing the structural patterns of timeout risks, we develop a risk data counting algorithm; and we also give some tactics for applying our approach more effectively. Experimental results show that our approach has almost the same running speed compared with the fast and interactive WCET analysis, but it saves more time in identifying real timeliness defects.

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