Nemer, Fadia (1980....).
Overview
Works:  2 works in 3 publications in 1 language and 3 library holdings 

Roles:  Author 
Publication Timeline
.
Most widely held works by
Fadia Nemer
Optimisation de l'estimation du WCET par analyse intertâche du cache d'intructions by
Fadia Nemer(
Book
)
2 editions published in 2008 in French and held by 2 WorldCat member libraries worldwide
The main characteristic of hard realtime systems is that they must guarantee a correct timing behaviour. Schedulability analysis methods are commonly used in hard realtime systems to check whether or not all tasks deadlines will be met. Most of them rely on the knowledge of an upper bound on the computation time of every task, named WCET (WorstCase Execution Time). The WCET of a program can be computed by simulation or by performing a static analysis. Dynamic analyses give the actual WCET of a program if we can simulate all possible combinations of input data values and initial system states. Which is clearly impractical due to the exponentially number of simulations required. As a result, we compute an estimate of the actual WCET by performing a static analysis of the program despite of the pessimism generated by the approximations. Most of these analyses are performed at the task so they don't take advantage from the features of the multitasking realtime systems such as the tasks' chaining that affects straightforwardly the accuracy of the WCET estimation. We propose an approach that studies the instruction cache behavior of a static tasks scheduling for a single processor multitasking realtime application assuming that no preemption is allowed between and inside the tasks. The main goal consists of replacing the conservative approximations that consider an empty or undefined cache state before the task execution, by an abstract cache state. The WCET estimation is thus improved. We also present a free realtime benchmark, PapaBench. This benchmark is designed to be valuable for experimental works in WCET computation and may be also useful for scheduling analysis
2 editions published in 2008 in French and held by 2 WorldCat member libraries worldwide
The main characteristic of hard realtime systems is that they must guarantee a correct timing behaviour. Schedulability analysis methods are commonly used in hard realtime systems to check whether or not all tasks deadlines will be met. Most of them rely on the knowledge of an upper bound on the computation time of every task, named WCET (WorstCase Execution Time). The WCET of a program can be computed by simulation or by performing a static analysis. Dynamic analyses give the actual WCET of a program if we can simulate all possible combinations of input data values and initial system states. Which is clearly impractical due to the exponentially number of simulations required. As a result, we compute an estimate of the actual WCET by performing a static analysis of the program despite of the pessimism generated by the approximations. Most of these analyses are performed at the task so they don't take advantage from the features of the multitasking realtime systems such as the tasks' chaining that affects straightforwardly the accuracy of the WCET estimation. We propose an approach that studies the instruction cache behavior of a static tasks scheduling for a single processor multitasking realtime application assuming that no preemption is allowed between and inside the tasks. The main goal consists of replacing the conservative approximations that consider an empty or undefined cache state before the task execution, by an abstract cache state. The WCET estimation is thus improved. We also present a free realtime benchmark, PapaBench. This benchmark is designed to be valuable for experimental works in WCET computation and may be also useful for scheduling analysis
Optimisation de l'estimation du WCET par analyse intertâche du cache d'intructions by
Fadia Nemer(
)
1 edition published in 2008 in French and held by 1 WorldCat member library worldwide
The main characteristic of hard realtime systems is that they must guarantee a correct timing behaviour. Schedulability analysis methods are commonly used in hard realtime systems to check whether or not all tasks deadlines will be met. Most of them rely on the knowledge of an upper bound on the computation time of every task, named WCET (WorstCase Execution Time). The WCET of a program can be computed by simulation or by performing a static analysis. Dynamic analyses give the actual WCET of a program if we can simulate all possible combinations of input data values and initial system states. Which is clearly impractical due to the exponentially number of simulations required. As a result, we compute an estimate of the actual WCET by performing a static analysis of the program despite of the pessimism generated by the approximations. Most of these analyses are performed at the task so they don't take advantage from the features of the multitasking realtime systems such as the tasks' chaining that affects straightforwardly the accuracy of the WCET estimation. We propose an approach that studies the instruction cache behavior of a static tasks scheduling for a single processor multitasking realtime application assuming that no preemption is allowed between and inside the tasks. The main goal consists of replacing the conservative approximations that consider an empty or undefined cache state before the task execution, by an abstract cache state. The WCET estimation is thus improved. We also present a free realtime benchmark, PapaBench. This benchmark is designed to be valuable for experimental works in WCET computation and may be also useful for scheduling analysis
1 edition published in 2008 in French and held by 1 WorldCat member library worldwide
The main characteristic of hard realtime systems is that they must guarantee a correct timing behaviour. Schedulability analysis methods are commonly used in hard realtime systems to check whether or not all tasks deadlines will be met. Most of them rely on the knowledge of an upper bound on the computation time of every task, named WCET (WorstCase Execution Time). The WCET of a program can be computed by simulation or by performing a static analysis. Dynamic analyses give the actual WCET of a program if we can simulate all possible combinations of input data values and initial system states. Which is clearly impractical due to the exponentially number of simulations required. As a result, we compute an estimate of the actual WCET by performing a static analysis of the program despite of the pessimism generated by the approximations. Most of these analyses are performed at the task so they don't take advantage from the features of the multitasking realtime systems such as the tasks' chaining that affects straightforwardly the accuracy of the WCET estimation. We propose an approach that studies the instruction cache behavior of a static tasks scheduling for a single processor multitasking realtime application assuming that no preemption is allowed between and inside the tasks. The main goal consists of replacing the conservative approximations that consider an empty or undefined cache state before the task execution, by an abstract cache state. The WCET estimation is thus improved. We also present a free realtime benchmark, PapaBench. This benchmark is designed to be valuable for experimental works in WCET computation and may be also useful for scheduling analysis
Audience Level
0 

1  
General  Special 
Related Identities
 Bahsoun, JeanPaul (1953....). Thesis advisor
 Université Toulouse 3 Paul Sabatier (1969....). Degree grantor
 Cassé, Hugues (19......; enseignantchercheur en informatique) Thesis advisor
Languages