MPSoCBench : um framework para avaliação de ferramentas e metodologias para sistemas multiprocessados em chip

Orientador: Rodolfo Jardim de AzevedoTese (doutorado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Recentes metodologias e ferramentas de projetos de sistemas multiprocessados em chip (MPSoC) aumentam a produtividade por meio da utilização de plataformas baseadas em simuladores, antes de definir os últimos detalhes da arquitetura. No entanto, a simulação só é eficiente quando utiliza ferramentas de modelagem que suportem a descrição do comportamento do sistema em um elevado nível de abstração. A escassez de plataformas virtuais de MPSoCs que integrem hardware e software escaláveis nos motivou a desenvolver o MPSoCBench, que consiste de um conjunto escalável de MPSoCs incluindo quatro modelos de processadores (PowerPC, MIPS, SPARC e ARM), organizado em plataformas com 1, 2, 4, 8, 16, 32 e 64 núcleos, cross-compiladores, IPs, interconexões, 17 aplicações paralelas e estimativa de consumo de energia para os principais componentes (processadores, roteadores, memória principal e caches). Uma importante demanda em projetos MPSoC é atender às restrições de consumo de energia o mais cedo possível. Considerando que o desempenho do processador está diretamente relacionado ao consumo, há um crescente interesse em explorar o trade-off entre consumo de energia e desempenho, tendo em conta o domínio da aplicação alvo. Técnicas de escalabilidade dinâmica de freqüência e voltagem fundamentam-se em gerenciar o nível de tensão e frequência da CPU, permitindo que o sistema alcance apenas o desempenho suficiente para processar a carga de trabalho, reduzindo, consequentemente, o consumo de energia. Para explorar a eficiência energética e desempenho, foram adicionados recursos ao MPSoCBench, visando explorar escalabilidade dinâmica de voltaegem e frequência (DVFS) e foram validados três mecanismos com base na estimativa dinâmica de energia e taxa de uso de CPUAbstract: Recent design methodologies and tools aim at enhancing the design productivity by providing a software development platform before the definition of the final Multiprocessor System on Chip (MPSoC) architecture details. However, simulation can only be efficiently performed when using a modeling and simulation engine that supports system behavior description at a high abstraction level. The lack of MPSoC virtual platform prototyping integrating both scalable hardware and software in order to create and evaluate new methodologies and tools motivated us to develop the MPSoCBench, a scalable set of MPSoCs including four different ISAs (PowerPC, MIPS, SPARC, and ARM) organized in platforms with 1, 2, 4, 8, 16, 32, and 64 cores, cross-compilers, IPs, interconnections, 17 parallel version of software from well-known benchmarks, and power consumption estimation for main components (processors, routers, memory, and caches). An important demand in MPSoC designs is the addressing of energy consumption constraints as early as possible. Whereas processor performance comes with a high power cost, there is an increasing interest in exploring the trade-off between power and performance, taking into account the target application domain. Dynamic Voltage and Frequency Scaling techniques adaptively scale the voltage and frequency levels of the CPU allowing it to reach just enough performance to process the system workload while meeting throughput constraints, and thereby, reducing the energy consumption. To explore this wide design space for energy efficiency and performance, both for hardware and software components, we provided MPSoCBench features to explore dynamic voltage and frequency scalability (DVFS) and evaluated three mechanisms based on energy estimation and CPU usage rateDoutoradoCiência da ComputaçãoDoutora em Ciência da Computaçã

Standart-konformes Snapshotting für SystemC Virtuelle Plattformen

The steady increase in complexity of high-end embedded systems goes along with an increasingly complex design process. We are currently still in a transition phase from Hardware-Description Language (HDL) based design towards virtual-platform-based design of embedded systems. As design complexity rises faster than developer productivity a gap forms. Restoring productivity while at the same time managing increased design complexity can also be achieved through focussing on the development of new tools and design methodologies. In most application areas, high-level modelling languages such as SystemC are used in early design phases. In modern software development Continuous Integration (CI) is used to automatically test if a submitted piece of code breaks functionality. Application of the CI concept to embedded system design and testing requires fast build and test execution times from the virtual platform framework. For this use case the ability to save a specific state of a virtual platform becomes necessary. The saving and restoring of specific states of a simulation requires the ability to serialize all data structures within the simulation models. Improving the frameworks and establishing better methods will only help to narrow the design gap, if these changes are introduced with the needs of the engineers and developers in mind. Ultimately, it is their productivity that shall be improved. The ability to save the state of a virtual platform enables developers to run longer test campaigns that can even contain randomized test stimuli. If the saved states are modifiable the developers can inject faulty states into the simulation models. This work contributes an extension to the SoCRocket virtual platform framework to enable snapshotting. The snapshotting extension can be considered a reference implementation as the utilization of current SystemC/TLM standards makes it compatible to other frameworkds. Furthermore, integrating the UVM SystemC library into the framework enables test driven development and fast validation of SystemC/TLM models using snapshots. These extensions narrow the design gap by supporting designers, testers and developers to work more efficiently.Die stetige Steigerung der Komplexität eingebetteter Systeme geht einher mit einer ebenso steigenden Komplexität des Entwurfsprozesses. Wir befinden uns momentan in der Übergangsphase vom Entwurf von eingebetteten Systemen basierend auf Hardware-Beschreibungssprachen hin zum Entwurf ebendieser basierend auf virtuellen Plattformen. Da die Entwurfskomplexität rasanter steigt als die Produktivität der Entwickler, entsteht eine Kluft. Die Produktivität wiederherzustellen und gleichzeitig die gesteigerte Entwurfskomplexität zu bewältigen, kann auch erreicht werden, indem der Fokus auf die Entwicklung neuer Werkzeuge und Entwurfsmethoden gelegt wird. In den meisten Anwendungsgebieten werden Modellierungssprachen auf hoher Ebene, wie zum Beispiel SystemC, in den frühen Entwurfsphasen benutzt. In der modernen Software-Entwicklung wird Continuous Integration (CI) benutzt um automatisiert zu überprüfen, ob eine eingespielte Änderung am Quelltext bestehende Funktionalitäten beeinträchtigt. Die Anwendung des CI-Konzepts auf den Entwurf und das Testen von eingebetteten Systemen fordert schnelle Bau- und Test-Ausführungszeiten von dem genutzten Framework für virtuelle Plattformen. Für diesen Anwendungsfall wird auch die Fähigkeit, einen bestimmten Zustand der virtuellen Plattform zu speichern, erforderlich. Das Speichern und Wiederherstellen der Zustände einer Simulation erfordert die Serialisierung aller Datenstrukturen, die sich in den Simulationsmodellen befinden. Das Verbessern von Frameworks und Etablieren besserer Methodiken hilft nur die Entwurfs-Kluft zu verringern, wenn diese Änderungen mit Berücksichtigung der Bedürfnisse der Entwickler und Ingenieure eingeführt werden. Letztendlich ist es ihre Produktivität, die gesteigert werden soll. Die Fähigkeit den Zustand einer virtuellen Plattform zu speichern, ermöglicht es den Entwicklern, längere Testkampagnen laufen zu lassen, die auch zufällig erzeugte Teststimuli beinhalten können oder, falls die gespeicherten Zustände modifizierbar sind, fehlerbehaftete Zustände in die Simulationsmodelle zu injizieren. Mein mit dieser Arbeit geleisteter Beitrag beinhaltet die Erweiterung des SoCRocket Frameworks um Checkpointing Funktionalität im Sinne einer Referenzimplementierung. Weiterhin ermöglicht die Integration der UVM SystemC Bibliothek in das Framework die Umsetzung der testgetriebenen Entwicklung und schnelle Validierung von SystemC/TLM Modellen mit Hilfe von Snapshots

Nouvelles approches pour la conception d'outils CAO pour le domaine des systèmes embarqués

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Modeling and Simulation in Engineering

This book provides an open platform to establish and share knowledge developed by scholars, scientists, and engineers from all over the world, about various applications of the modeling and simulation in the design process of products, in various engineering fields. The book consists of 12 chapters arranged in two sections (3D Modeling and Virtual Prototyping), reflecting the multidimensionality of applications related to modeling and simulation. Some of the most recent modeling and simulation techniques, as well as some of the most accurate and sophisticated software in treating complex systems, are applied. All the original contributions in this book are jointed by the basic principle of a successful modeling and simulation process: as complex as necessary, and as simple as possible. The idea is to manipulate the simplifying assumptions in a way that reduces the complexity of the model (in order to make a real-time simulation), but without altering the precision of the results