CUCU-GROSJEAN , Liliana

In Chapter 1 we present our contributionto the scheduling of real-time systems on multiprocessor platforms. We start thechapter by providing an exhaustive list of all results we proposed on this topic andthen we detail two contributions: the predictability results and the schedulabilityanalysis. We present the proofs of these results as their...

Proposed originally as stochastic scheduling, the probabilistic real-time scheduling concerns real-time systems with at least one parameter described by a random variable. Any parameter of the task may have such description, but the existing work concentrates on the probabilistic worst-case execution times. This lecture will provide the main...

Since the early work of Lehoczky on real-time queuing theory, probabilistic approaches have addressed many aspects of real-time systems. This presentation concentrates on the migration of probabilistic methods from modelling soft real-time systems to analysing hard real-time systems. The history of this migration is outlined over the last two...

Proposed originally as stochastic scheduling, the probabilistic real-time scheduling concerns real-time systems with at least one parameter described by a random variable. Any parameter of the task may have such description, but the existing work concentrates on the probabilistic worst-case execution times. This lecture will provide the main...

During the last twenty years different design solutions have been proposed for time critical embeddedsystems through pessimistic estimation of performances of the processors (thus increased costs) whileusing average time behavior processors. A possible solution to decrease the pessimism while designingtime critical embedded systems is to enrich...

In this paper we show for the first time that the probabilistic real-time analyses do not have stronger requirements from the task systems than a deterministic real-time analysis (with respect to the hypothesis of independence originally introduced by Liu and Layland), as long as pWCETs are used.

In this paper we show for the first time that the probabilistic real-time analyses do not have stronger requirements from the task systems than a deterministic real-time analysis (with respect to the hypothesis of independence originally introduced by Liu and Layland), as long as pWCETs are used.

Since the early work of Lehoczky on real-time queuing theory, probabilistic approaches have addressed many aspects of real-time systems. This presentation concentrates on the migration of probabilistic methods from modelling soft real-time systems to analysing hard real-time systems. The history of this migration is outlined over the last two...

In this paper, we consider a probabilistic model for real-time task systems with probabilistic worst-case execution times, probabilistic minimum inter-arrival times and probabilistic deadlines. We propose an analysis computing response time distributions of the tasks scheduled on one processor under a task-level fixed-priority preemptive...

National audience

In this paper, we consider a probabilistic model for real-time task systems with probabilistic worst-case execution times, probabilistic minimum inter-arrival times and probabilistic deadlines. We propose an analysis computing response time distributions of the tasks scheduled on one processor under a task-level fixed-priority preemptive...

International audience

In this paper we provide a schedulability test for dependant periodic task systems scheduled using non-preemptive policies. We consider the case of one processor and the schedulability test is based on the periodicity of a feasible schedule. A feasible schedule is periodic if it repeats from a time instant s with a period p. In the case of one...

International audience

Challenges within the real-time research are mostly in terms of modeling and analyzing the complexity of actual real-time embed- ded systems. Probabilities are effective in both modeling and analyzing embedded systems by increasing the amount of information for the description of elements composing the system. Elements are tasks and...

International audience

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International audience

In this paper, we investigate Static Probabilistic Timing Analysis (SPTA) for sin- gle processor real-time systems that use a cache with an evict-on-miss random replacement policy. We show that previously published formulae for the probability of a cache hit can produce results that are optimistic and unsound when used to compute probabilistic...

This paper gives and proves correct a simulation interval for any schedule generated by a deterministic and memoryless scheduler (i.e., one where the scheduling decision is the same and unique for any two identical system states) for identical multiprocessor platforms. We first consider independent periodic tasks, then generalize the simulation...

Probabilistic analysis are considered nowadays an interesting solution for real-time systems as the probabilityof appearance of worst-case values is small (10−45 per hour of functioning) compared to the acceptedprobability of failure (10−9 per hour of functioning for the highest safety level in avionics). In order to takeinto account this...

This paper is proposing a general periodicity result concerning any deterministic and memoryless scheduling algorithm (including non-work-conserving algorithms), for any context, on identical multiprocessor platforms. By context we mean the hardware architecture (uniprocessor, multicore), as well as task constraints like critical sections,...

International audience

This paper is proposing a general periodicity result concerning any deterministic and memoryless scheduling algorithm (including non-work-conserving algorithms), for any context, on identical multiprocessor platforms. By context we mean the hardware architecture (uniprocessor, multicore), as well as task constraints like critical sections,...