STORM: a Simulation Tool for Real-time Multiprocessor Scheduling Evaluation

STORM est un outil de simulation destiné à l'analyse du comportement et l'évaluation de performances de politiques d'ordonnancement. Il permet, à partir de la spécification des caractéristiques d'une architecture logicielle (les tâches à ordonnancer), d'une architecture matérielle (les ressources d'exécution) de simuler une exécution de ces tâches sur ces ressources selon les règles de cette politique, ceci sur une durée d'étude donnée

Simulation of Efficient Real-Time Scheduling and Power Optimisation

International audienceSophisticated applications turn out to be executed upon more than one CPU for practical and economic reasons. Due to advances in circuit technology and performance limitation, multi-core technology has become the mainstream in CPU designs. However, the most serious limitation of these devices is the battery lifetime since battery technology is not keeping up with the rest of the power-hungry processors and peripherals used in today's mobile devices. As a solution, many investigations have turned toward the algorithms of power management combined with some scheduling policies. They can make significant energy saving while preserving the temporal constraints of these embedded systems. Reducing energy, especially, affect not only the battery lifetime, but also aim to reduce the heat generated by real-time embedded controller in various products or even to decrease the conditions of cooling and the costs, in the large scale, of giant multiprocessor computers. To assess the behavior and performance of the strategy of scheduling a flexible multiprocessor scheduling simulation and evaluation platform is needed. This paper puts forth the claim that the STORM simulator improves application quality both in terms of execution time and energy consumption for a high performance mobile computing embedded system design

YARTISS: A Tool to Visualize, Test, Compare and Evaluate Real-Time Scheduling Algorithms

International audienceIn this paper, we present a free software written in Java, YARTISS, which is a real-time multiprocessor scheduling simulator. It is aimed at comparing user-customized algorithms with ones from the literature on real-time scheduling. This simulator is designed as an easy-to-use modular tool in which new modules can be added without the need to decompress, edit nor recompile existing parts. It can simulate the execution of a large number of concurrent periodic independent task sets on multiprocessor systems and generate clear visual results of the scheduling process (both schedules and tunable metrics presentations). Other task models are already implemented in the simulator, like graph tasks with precedence constraints and it is easily extensible to other task models. Moreover, YARTISS can simulate task sets in which energy consumption is a scheduling parameter in the same manner as Worst Case Execution Time (WCET)

Simulation of Real-Time Scheduling with Various Execution Time Models

Presented during the Work-in-Progress session (WiP session)International audienceIn this paper, we present SimSo, a simulator that aims at facilitating the design of experimental evaluations for real-time scheduling algorithms. Currently, more than twenty-five algorithms were implemented. Special attention is paid to the execution time model of tasks. We show that the worst-case execution time for experimental simulation can introduce a bias in evaluation and we discuss as a work in progress how cache effects could be taken into consideration in the simulation

YARTISS: A Generic, Modular and Energy-Aware Scheduling Simulator for Real-Time Multiprocessor Systems

In this report, we present a free software written in Java, YARTISS, which is a real-time multiprocessor scheduling simulator. It is aimed at comparing user-customized algorithms with ones from the literature on real-time scheduling. This simulator is designed as an easy-to-use modular tool in which new modules can be added without the need to decompress, edit nor recompile existing parts. It can sim-ulate the execution of a large number of concurrent periodic independent tasksets on multiprocessor platforms and generate clear visual results of the scheduling process (both schedules and tunable metrics presentations). Other task models are already implemented in the simulator, like graph tasks with precedence constraints and it is easily extensible to other task models. Moreover, YARTISS can simulate tasksets in which energy consumption is a scheduling parameter in the same manner as Worst Case Execution Time (WCET)

GEN4MAST: A Tool for the Evaluation of Real-Time Techniques Using a Supercomputer

REACTION 2014. 3rd International Workshop on Real-time and Distributed Computing in Emerging Applications. Rome, Italy. December 2nd, 2014.The constant development of new approaches in real-time systems makes it necessary to create tools or methods to perform their evaluations in an efficient way. It is not uncommon for these evaluations to be constrained by the processing power of current personal computers. Thus, it is still a challenging issue to know whether a specific technique could perform better than another one, or the improvement remains invariable in all circumstances. In this paper we present the GEN4MAST tool, which can take advantage of the performance of a supercomputer to execute longer evaluations that wouldn’t be possible in a common computer. GEN4MAST is built around the widely used MAST tool, automating the whole process of distributed systems generation, execution of the requested analysis or optimization techniques, and the processing of the results. GEN4MAST integrates several generation methods to create realistic workloads. We show that the different methods can have a great impact on the results of distributed systems.This work has been funded in part by the Spanish Government and FEDER funds under grant number TIN2011-28567-C03-02 (HI-PARTES)

Model Driven Engineering with Capella and AADL

The development of real time embedded equipments is a challenging task that requires the elaboration of multiple models in several domains, notably system, electronics and software, spanning a large spectrum of multiple abstraction levels and viewpoints: structural, behavioral, dependability, etc. These models serve various purposes: specification, design, evaluation or verification and validation. Today, no single modeling language and environment covers all these aspects. While Capella – an open source modeling language and environment for system engineering developed by Thales – fits well to the most early stages of the development process, AADL – the Architecture Analysis and Design Language defined by the Society of Automotive Engineers – provides powerful capabilities to describe and analyze the design artifacts of the software point of view that appear during the latest phase of the design. This is why they have both been selected in the project INGEQUIP of IRT Saint Exupéry. While using different modeling languages for different purpose is perfectly acceptable in a development process, it is important to guarantee that information remain consistent across all models. This is why building a formalized bridge between Capella and AADL is an essential piece of INGEQUIP process. In this paper, after an introduction to the context of INGEQUIP, the high level semantics of Capella and AADL are compared. The mapping used in INGEQUIP between Capella physical models and AADL abstract models is then described. The whole approach is illustrated by some elements coming from the design of TwIRTee – the robotic demonstrator of INGEQUIP – before concluding

Comparing the schedulers and power saving strategies with SPARTS

We have developed SPARTS, a simulator of a generic embedded real-time device. It is designed to be extensible to accommodate different task properties, scheduling algorithms and/or hardware models for the wide variety of applications. SPARTS was developed to help the community investigate the behaviour of the real-time embedded systems and to quantify the associated constraints/overheads

The work/exchange model: a generalized approach to dynamic load balancing

A crucial concern in software development is reducing program execution time. Parallel processing is often used to meet this goal. However, parallel processing efforts can lead to many pitfalls and problems. One such problem is to distribute the workload among processors in such a way that minimum execution time is obtained. The common approach is to use a load balancer to distribute equal or nearly equal quantities of workload on each processor. Unfortunately, this approach relies on a naive definition of load imbalance and often fails to achieve the desired goal. A more sophisticated definition should account for the affects of additional factors including communication delay costs, network contention, and architectural issues. Consideration of additional factors led us to the realization that optimal load distribution does not always result from equal load distribution. In this dissertation, we tackle the difficult problem of defining load imbalance. This is accomplished through the development of a parallel program model called the Generalized Work/Exchange Model. Associated with the model are equations for a restricted set of deterministically balanced programs that characterize idle time, elapsed time, and potential speedup. With the aid of the model, several common myths about load imbalance are exposed. A useful application called a load balancer enhancer is also presented which is applicable to the more general, quasi-static load unbalanced program

A Framework for Fixed Priority Periodic Scheduling Synthesis from Synchronous Data-flow Graphs

International audienceUnlabelled - Medicinally active compounds in the flavonoid class of phytochemicals are being studied for antiviral action against various DNA and RNA viruses. Quercetin is a flavonoid present in a wide range of foods, including fruits and vegetables. It is said to be efficient against a wide range of viruses. This research investigated the usefulness of Quercetin against Hepatitis C virus, Dengue type 2 virus, Ebola virus, and Influenza A using computational models. A molecular docking study using the online tool PockDrug was accomplished to identify the best binding sites between Quercetin and PubChem-based receptors. Network-pharmacological assay to opt to verify function-specific gene-compound interactions using STITCH, STRING, GSEA, Cytoscape plugin cytoHubba. Quercetin explored tremendous binding affinity against NS5A protein for HCV with a docking score of - 6.268 kcal/mol, NS5 for DENV-2 with a docking score of - 5.393 kcal/mol, VP35 protein for EBOV with a docking score of - 4.524 kcal/mol, and NP protein for IAV with a docking score of - 6.954 kcal/mol. In the network-pharmacology study, out of 39 hub genes, 38 genes have been found to interact with Quercetin and the top interconnected nodes in the protein-protein network were (based on the degree of interaction with other nodes) and Negative binding energies were noticed in Quercetin-receptor interaction. Results demonstrate that Quercetin could be a potential antiviral agent against these viral diseases with further study in models. Supplementary information - The online version contains supplementary material available at 10.1007/s40203-022-00132-2