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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Hybrid Parallel Computing Strategies for Scientific Computing Applications

Lee, Joo Hong 10 October 2012 (has links)
Multi-core, multi-processor, and Graphics Processing Unit (GPU) computer architectures pose significant challenges with respect to the efficient exploitation of parallelism for large-scale, scientific computing simulations. For example, a simulation of the human tonsil at the cellular level involves the computation of the motion and interaction of millions of cells over extended periods of time. Also, the simulation of Radiative Heat Transfer (RHT) effects by the Photon Monte Carlo (PMC) method is an extremely computationally demanding problem. The PMC method is example of the Monte Carlo simulation method—an approach extensively used in wide of application areas. Although the basic algorithmic framework of these Monte Carlo methods is simple, they can be extremely computationally intensive. Therefore, an efficient parallel realization of these simulations depends on a careful analysis of the nature these problems and the development of an appropriate software framework. The overarching goal of this dissertation is develop and understand what the appropriate parallel programming model should be to exploit these disparate architectures, both from the metric of efficiency, as well as from a software engineering perspective. In this dissertation we examine these issues through a performance study of PathSim2, a software framework for the simulation of large-scale biological systems, using two different parallel architectures’ distributed and shared memory. First, a message-passing implementation of a multiple germinal center simulation by PathSim2 is developed and analyzed for distributed memory architectures. Second, a germinal center simulation is implemented on shared memory architecture with two parallelization strategies based on Pthreads and OpenMP. Finally, we present work targeting a complete hybrid, parallel computing architecture. With this work we develop and analyze a software framework for generic Monte Carlo simulations implemented on multiple, distributed memory nodes consisting of a multi-core architecture with attached GPUs. This simulation framework is divided into two asynchronous parts: (a) a threaded, GPU-accelerated pseudo-random number generator (or producer), and (b) a multi-threaded Monte Carlo application (or consumer). The advantage of this approach is that this software framework can be directly used within any Monte Carlo application code, without requiring application-specific programming of the GPU. We examine this approach through a performance study of the simulation of RHT effects by the PMC method on a hybrid computing architecture. We present a theoretical analysis of our proposed approach, discuss methods to optimize performance based on this analysis, and compare this analysis to experimental results obtained from simulations run on two different hybrid, parallel computing architectures. / Ph. D.
132

High-Performance Network-on-Chip Design for Many-Core Processors

Wang, Boqian January 2020 (has links)
With the development of on-chip manufacturing technologies and the requirements of high-performance computing, the core count is growing quickly in Chip Multi/Many-core Processors (CMPs) and Multiprocessor System-on-Chip (MPSoC) to support larger scale parallel execution. Network-on-Chip (NoC) has become the de facto solution for CMPs and MPSoCs in addressing the communication challenge. In the thesis, we tackle a few key problems facing high-performance NoC designs. For general-purpose CMPs, we encompass a full system perspective to design high-performance NoC for multi-threaded programs. By exploring the cache coherence under the whole system scenario, we present a smart communication service called Advance Virtual Channel Reservation (AVCR) to provide a highway to target packets, which can greatly reduce their contention delay in NoC. AVCR takes advantage of the fact that we can know or predict the destination of some packets ahead of their arrival at the Network Interface (NI). Exploiting the time interval before a packet is ready, AVCR establishes an end-to-end highway from the source NI to the destination NI. This highway is built up by reserving the Virtual Channel (VC) resources ahead of the target packet transmission and offering priority service to flits in the reserved VC in the wormhole router, which can avoid the target packets’ VC allocation and switch arbitration delay. Besides, we also propose an admission control method in NoC with a centralized Artificial Neural Network (ANN) admission controller, which can improve system performance by predicting the most appropriate injection rate of each node using the network performance information. In the online control process, a data preprocessing unit is applied to simplify the ANN architecture and make the prediction results more accurate. Based on the preprocessed information, the ANN predictor determines the control strategy and broadcasts it to each node where the admission control will be applied. For application-specific MPSoCs, we focus on developing high-performance NoC and NI compatible with the common AMBA AXI4 interconnect protocol. To offer the possibility of utilizing the AXI4 based processors and peripherals in the on-chip network based system, we propose a whole system architecture solution to make the AXI4 protocol compatible with the NoC based communication interconnect in the many-core system. Due to possible out-of-order transmission in the NoC interconnect, which conflicts with the ordering requirements specified by the AXI4 protocol, in the first place, we especially focus on the design of the transaction ordering units, realizing a high-performance and low cost solution to the ordering requirements. The microarchitectures and the functionalities of the transaction ordering units are also described and explained in detail for ease of implementation. Then, we focus on the NI and the Quality of Service (QoS) support in NoC. In our design, the NI is proposed to make the NoC architecture independent from the AXI4 protocol via message format conversion between the AXI4 signal format and the packet format, offering high flexibility to the NoC design. The NoC based communication architecture is designed to support high-performance multiple QoS schemes. The NoC system contains Time Division Multiplexing (TDM) and VC subnetworks to apply multiple QoS schemes to AXI4 signals with different QoS tags and the NI is responsible for traffic distribution between two subnetworks. Besides, a QoS inheritance mechanism is applied in the slave-side NI to support QoS during packets’ round-trip transfer in NoC. / Med utvecklingen av tillverkningsteknologi av on-chip och kraven på högpresterande da-toranläggning växer kärnantalet snabbt i Chip Multi/Many-core Processors (CMPs) ochMultiprocessor Systems-on-Chip (MPSoCs) för att stödja större parallellkörning. Network-on-Chip (NoC) har blivit den de facto lösningen för CMP:er och MPSoC:er för att mötakommunikationsutmaningen. I uppsatsen tar vi upp några viktiga problem med hög-presterande NoC-konstruktioner.Allmänna CMP:er omfattas ett fullständigt systemperspektiv för att design högprester-ande NoC för flertrådad program. Genom att utforska cachekoherensen under hela system-scenariot presenterar vi en smart kommunikationstjänst, AVCR (Advance Virtual ChannelReservation) för att tillhandahålla en motorväg till målpaket, vilket i hög grad kan min-ska deras förseningar i NoC. AVCR utnyttjar det faktum att vi kan veta eller förutsägadestinationen för vissa paket före deras ankomst till nätverksgränssnittet (Network inter-face, NI). Genom att utnyttja tidsintervallet innan ett paket är klart, etablerar AVCRen ände till ände motorväg från källan NI till destinationen NI. Denna motorväg byggsupp genom att reservera virtuell kanal (Virtual Channel, VC) resurser före målpaket-söverföringen och erbjuda prioriterade tjänster till flisar i den reserverade VC i wormholerouter. Dessutom föreslår vi också en tillträdeskontrollmetod i NoC med en centraliseradartificiellt neuronät (Artificial Neural Network, ANN) tillträdeskontroll, som kan förbättrasystemets prestanda genom att förutsäga den mest lämpliga injektionshastigheten för varjenod via nätverksprestationsinformationen. I onlinekontrollprocessen används en förbehan-dlingsenhet på data för att förenkla ANN-arkitekturen och göra förutsägningsresultatenmer korrekta. Baserat på den förbehandlade informationen bestämmer ANN-prediktornkontrollstrategin och sänder den till varje nod där tillträdeskontrollen kommer att tilläm-pas.För applikationsspecifika MPSoC:er fokuserar vi på att utveckla högpresterande NoCoch NI kompatibla med det gemensamma AMBA AXI4 protokoll. För att erbjuda möj-ligheten att använda AXI4-baserade processorer och kringutrustning i det on-chip baseradenätverkssystemet föreslår vi en hel systemarkitekturlösning för att göra AXI4 protokolletkompatibelt med den NoC-baserade kommunikation i det multikärnsystemet. På grundav den out-of-order överföring i NoC, som strider mot ordningskraven som anges i AXI4-protokollet, fokuserar vi i första hand på utformningen av transaktionsordningsenheterna,för att förverkliga en hög prestanda och låg kostnad-lösning på ordningskraven. Sedanfokuserar vi på NI och Quality of Service (QoS)-stödet i NoC. I vår design föreslås NI attgöra NoC-arkitekturen oberoende av AXI4-protokollet via meddelandeformatkonverteringmellan AXI4 signalformatet och paketformatet, vilket erbjuder NoC-designen hög flexi-bilitet. Den NoC-baserade kommunikationsarkitekturen är utformad för att stödja fleraQoS-schema med hög prestanda. NoC-systemet innehåller Time-Division Multiplexing(TDM) och VC-subnät för att tillämpa flera QoS-scheman på AXI4-signaler med olikaQoS-taggar och NI ansvarar för trafikdistribution mellan två subnät. Dessutom tillämpasen QoS-arvsmekanism i slav-sidan NI för att stödja QoS under paketets tur-returöverföringiNoC / <p>QC 20201008</p>
133

Stratégie de réduction des cycles thermiques pour systèmes temps-réel multiprocesseurs sur puce / Strategy to reduce thermal cycles for real-time multiprocessor systems-on-chip

Baati, Khaled 19 December 2013 (has links)
L'augmentation de la densité des transistors dans les circuits électroniques conduit à une augmentation de la consommation d'énergie induisant des phénomènes thermiques plus complexes à maitriser. Dans le cas de systèmes embarqués en environnement où la température ambiante varie dans des proportions importantes (automobile par exemple), ces phénomènes peuvent conduire à des problèmes de fiabilité. Parmi les mécanismes de défaillance observés, on peut citer les cycles thermiques (CT) qui induisent des déformations dans les couches métalliques de la puce pouvant conduire à des fissurations. L’objectif de la thèse est de proposer pour des architectures de type multiprocesseur sur puce une technique de réduction des CT subis par les processeurs, et ce en respectant les contraintes temps réel des applications. L’exemple du circuit MPC5517 de Freescale a été considéré. Dans un premier temps un modèle thermique de ce circuit a été élaboré à partir de mesures par une caméra thermique sur ce circuit décapsulé. Un environnement de simulation a été mis en oeuvre pour permettre d’effectuer simultanément des analyses thermiques et d’ordonnancement de tâches et mettre en évidence l’influence de la température sur la puissance dissipée. Une heuristique globale pour réduire à la fois les CT et la température maximale des processeurs a été étudiée. Elle tient compte des variations de la température ambiante et se base sur les techniques DVFS et DPM. Les résultats de simulation avec les algorithmes d’ordonnancement globaux RM, EDF et EDZL et avec différentes charges processeur (sur un circuit type MPC5517 et un UltraSparc T1) illustrent l’efficacité de la technique proposée. / Increasing the density of transistors in electronic circuits leads to an increase in energy consumption resulting in more complex thermal phenomena to master. For systems embedded in environments where the ambient temperature can vary in large range (e.g. automotive), these thermal effects can induce reliability problems. Among classical failure mechanisms thermal cycles (CTs) produce deformations in materials and play a major role in the cracking of the metal layers in the chip. The aim of the thesis is to propose a reduction technique of CTs suffered by the processor cores in a multiprocessor on chip architecture such that real-time application constraints are met. The example of the Freescale MPC5517 circuit has been considered. In a first step a thermal model of this circuit was developed. This was achieved from measurements taken by a thermal camera on a decapsulated circuit. Next, a simulation environment has been implemented allowing both the analysis of thermal behavior and the scheduling of tasks so as to highlight the influence of temperature on the dissipated power. A global heuristic to reduce both the CTs and the maximum temperature of processors has been studied. It takes into account variations in the ambient temperature and is based on DVFS and DPM techniques. Simulation results with global scheduling algorithms RM, EDF and EDZL and different processor loads (for a MPC5517 type circuit and a T1 UltraSparc from Sun Microsystems) illustrate the effectiveness of the proposed technique.
134

Towards Low-Complexity Scalable Shared-Memory Architectures

Zeffer, Håkan January 2006 (has links)
<p>Plentiful research has addressed low-complexity software-based shared-memory systems since the idea was first introduced more than two decades ago. However, software-coherent systems have not been very successful in the commercial marketplace. We believe there are two main reasons for this: lack of performance and/or lack of binary compatibility.</p><p>This thesis studies multiple aspects of how to design future binary-compatible high-performance scalable shared-memory servers while keeping the hardware complexity at a minimum. It starts with a software-based distributed shared-memory system relying on no specific hardware support and gradually moves towards architectures with simple hardware support.</p><p>The evaluation is made in a modern chip-multiprocessor environment with both high-performance compute workloads and commercial applications. It shows that implementing the coherence-violation detection in hardware while solving the interchip coherence in software allows for high-performing binary-compatible systems with very low hardware complexity. Our second-generation hardware-software hybrid performs on par with, and often better than, traditional hardware-only designs.</p><p>Based on our results, we conclude that it is not only possible to design simple systems while maintaining performance and the binary-compatibility envelope, it is often possible to get better performance than in traditional and more complex designs.</p><p>We also explore two new techniques for evaluating a new shared-memory design throughout this work: adjustable simulation fidelity and statistical multiprocessor cache modeling.</p>
135

Towards Low-Complexity Scalable Shared-Memory Architectures

Zeffer, Håkan January 2006 (has links)
Plentiful research has addressed low-complexity software-based shared-memory systems since the idea was first introduced more than two decades ago. However, software-coherent systems have not been very successful in the commercial marketplace. We believe there are two main reasons for this: lack of performance and/or lack of binary compatibility. This thesis studies multiple aspects of how to design future binary-compatible high-performance scalable shared-memory servers while keeping the hardware complexity at a minimum. It starts with a software-based distributed shared-memory system relying on no specific hardware support and gradually moves towards architectures with simple hardware support. The evaluation is made in a modern chip-multiprocessor environment with both high-performance compute workloads and commercial applications. It shows that implementing the coherence-violation detection in hardware while solving the interchip coherence in software allows for high-performing binary-compatible systems with very low hardware complexity. Our second-generation hardware-software hybrid performs on par with, and often better than, traditional hardware-only designs. Based on our results, we conclude that it is not only possible to design simple systems while maintaining performance and the binary-compatibility envelope, it is often possible to get better performance than in traditional and more complex designs. We also explore two new techniques for evaluating a new shared-memory design throughout this work: adjustable simulation fidelity and statistical multiprocessor cache modeling.
136

Schedulability Tests for Real-Time Uni- and Multiprocessor Systems / Planbarkeitstests für Ein- und Mehrprozessor-Echtzeitsysteme unter besonderer Berücksichtigung des partitionierten Ansatzes

Müller, Dirk 07 April 2014 (has links) (PDF)
This work makes significant contributions in the field of sufficient schedulability tests for rate-monotonic scheduling (RMS) and their application to partitioned RMS. Goal is the maximization of possible utilization in worst or average case under a given number of processors. This scenario is more realistic than the dual case of minimizing the number of necessary processors for a given task set since the hardware is normally fixed. Sufficient schedulability tests are useful for quick estimates of task set schedulability in automatic system-synthesis tools and in online scheduling where exact schedulability tests are too slow. Especially, the approach of Accelerated Simply Periodic Task Sets (ASPTSs) and the concept of circular period similarity are cornerstones of improvements in the success ratio of such schedulability tests. To the best of the author's knowledge, this is the first application of circular statistics in real-time scheduling. Finally, the thesis discusses the use of sharp total utilization thresholds for partitioned EDF. A constant-time admission control is enabled with a controlled residual risk. / Diese Arbeit liefert entscheidende Beiträge im Bereich der hinreichenden Planbarkeitstests für ratenmonotones Scheduling (RMS) und deren Anwendung auf partitioniertes RMS. Ziel ist die Maximierung der möglichen Last im Worst Case und im Average Case bei einer gegebenen Zahl von Prozessoren. Dieses Szenario ist realistischer als der duale Fall der Minimierung der Anzahl der notwendigen Prozessoren für eine gegebene Taskmenge, da die Hardware normalerweise fixiert ist. Hinreichende Planbarkeitstests sind für schnelle Schätzungen der Planbarkeit von Taskmengen in automatischen Werkzeugen zur Systemsynthese und im Online-Scheduling sinnvoll, wo exakte Einplanungstests zu langsam sind. Insbesondere der Ansatz der beschleunigten einfach-periodischen Taskmengen und das Konzept der zirkulären Periodenähnlichkeit sind Eckpfeiler für Verbesserungen in der Erfolgsrate solcher Einplanungstests. Nach bestem Wissen ist das die erste Anwendung zirkulärer Statistik im Echtzeit-Scheduling. Schließlich diskutiert die Arbeit plötzliche Phasenübergänge der Gesamtlast für partitioniertes EDF. Eine Zugangskontrolle konstanter Zeitkomplexität mit einem kontrollierten Restrisiko wird ermöglicht.
137

High Level Design and Control of Adaptive Multiprocessor Systems-on-Chip

An, Xin 16 October 2013 (has links) (PDF)
La conception de systèmes embarqués modernes est de plus en plus complexe, car plus de fonctionnalités sont intégrées dans ces systèmes. En même temps, afin de répondre aux exigences de calcul tout en conservant une consommation d'énergie de faible niveau, MPSoCs sont apparus comme les principales solutions pour tels systèmes embarqués. En outre, les systèmes embarqués sont de plus en plus adaptatifs, comme l'adaptabilité peut apporter un certain nombre d'avantages, tels que la flexibilité du logiciel et l'efficacité énergétique. Cette thèse vise la conception sécuritaire de ces MPSoCs adaptatifs. Tout d'abord, chaque configuration de système doit être analysée en ce qui concerne ses propriétés fonctionnelles et non fonctionnelles. Nous présentons un cadre abstraite de conception et d'analyse qui permet des décisions d'implémentation rapide et rentable. Ce cadre est conçu comme un support de raisonnement intermédiaire pour les environnements de co-conception de logiciel / matériel au niveau de système. Il peut élaguer l'espace de conception à sa plus grande portée, et identifier les candidats de solutions de conception de manière rapide et efficace. Dans ce cadre, nous utilisons un codage basé sur l'horloge abstraite pour modéliser les comportements du système. Différents scénarios d'applications de mapping et de planification sur MPSoCs sont analysés via les traces d'horloge qui représentent les simulations du système. Les propriétés d'intérêt sont l'exactitude du comportement fonctionnel, la performance temporelle et la consommation d'énergie. Deuxièmement, la gestion de la reconfiguration de MPSoCs adaptatifs doit être abordée. Nous sommes particulièrement intéressés par les MPSoCs implémentés sur des architectures reconfigurables (ex. FPGAs) qui offrent une bonne flexibilité et une efficacité de calcul pour les MPSoCs adaptatifs. Nous proposons un cadre général de conception basé sur la technique de la synthèse de contrôleurs discrets (DCS) pour résoudre ce problème. L'avantage principal de cette technique est qu'elle permet une synthèse d'un contrôleur automatique selon une spécification des objectifs de contrôle. Dans ce cadre, le comportement de reconfiguration du système est modélisé en termes d'automates synchrones en parallèle. Le problème de calcul de la gestion reconfiguration selon de multiples objectifs concernant, par exemple, les usages des ressources, la performance et la consommation d'énergie, est codé comme un problème de DCS. Le langage de programmation BZR existant et l'outil Sigali sont employés pour effectuer DCS et générer un contrôleur qui satisfait aux exigences du système. Finalement, nous étudions deux façons différentes de combiner les deux cadres de conception proposées pour MPSoCs adaptatifs. Tout d'abord, ils sont combinés pour construire un flot de conception complet pour MPSoCs adaptatifs. Deuxièmement, ils sont combinés pour présenter la façon dont le manager run-time calculé par le second cadre peut être intégré dans le premier cadre afin de réaliser des simulations et des analyses combinées de MPSoCs adaptatifs.
138

Projeto de Sistemas Integrados de Prop?sito Geral Baseados em Redes em Chip Expandindo as Funcionalidades dos Roteadores para Execu??o de Opera??es: A plataforma IPNoSys

Ara?jo, S?lvio Roberto Fernandes de 30 March 2012 (has links)
Made available in DSpace on 2014-12-17T15:47:00Z (GMT). No. of bitstreams: 1 SilvioRFA_TESE.pdf: 5797455 bytes, checksum: 65da3be6db5be8c8185888e31c1f294c (MD5) Previous issue date: 2012-03-30 / It bet on the next generation of computers as architecture with multiple processors and/or multicore processors. In this sense there are challenges related to features interconnection, operating frequency, the area on chip, power dissipation, performance and programmability. The mechanism of interconnection and communication it was considered ideal for this type of architecture are the networks-on-chip, due its scalability, reusability and intrinsic parallelism. The networks-on-chip communication is accomplished by transmitting packets that carry data and instructions that represent requests and responses between the processing elements interconnected by the network. The transmission of packets is accomplished as in a pipeline between the routers in the network, from source to destination of the communication, even allowing simultaneous communications between pairs of different sources and destinations. From this fact, it is proposed to transform the entire infrastructure communication of network-on-chip, using the routing mechanisms, arbitration and storage, in a parallel processing system for high performance. In this proposal, the packages are formed by instructions and data that represent the applications, which are executed on routers as well as they are transmitted, using the pipeline and parallel communication transmissions. In contrast, traditional processors are not used, but only single cores that control the access to memory. An implementation of this idea is called IPNoSys (Integrated Processing NoC System), which has an own programming model and a routing algorithm that guarantees the execution of all instructions in the packets, preventing situations of deadlock, livelock and starvation. This architecture provides mechanisms for input and output, interruption and operating system support. As proof of concept was developed a programming environment and a simulator for this architecture in SystemC, which allows configuration of various parameters and to obtain several results to evaluate it / Aposta-se na pr?xima gera??o de computadores como sendo de arquitetura com m?ltiplos processadores e/ou processadores com v?rios n?cleos. Neste sentido h? desafios relacionados aos mecanismos de interconex?o, frequ?ncia de opera??o, ?rea ocupada em chip, pot?ncia dissipada, programabilidade e desempenho. O mecanismo de interconex?o e comunica??o considerado ideal para esse tipo de arquitetura s?o as redes em chip, pela escalabilidade, paralelismo intr?nseco e reusabilidade. A comunica??o nas redes em chip ? realizada atrav?s da transmiss?o de pacotes que carregam dados e instru??es que representam requisi??es e respostas entre os elementos processadores interligados pela rede. A transmiss?o desses pacotes acontece como em um pipeline entre os roteadores da rede, da origem at? o destino da comunica??o, permitindo inclusive comunica??es simult?neas entre pares de origem e destinos diferentes. Partindo desse fato, prop?ese transformar toda a infraestrutura de comunica??o de uma rede em chip, aproveitando os mecanismos de roteamento, arbitragem e memoriza??o em um sistema de processamento paralelo de alto desempenho. Nessa proposta os pacotes s?o formados por instru??es e dados que representam as aplica??es, os quais s?o executados nos roteadores enquanto s?o transmitidos, aproveitando o pipeline das transmiss?es e a comunica??o paralela. Em contrapartida, n?o s?o utilizados processadores tradicionais, mas apenas n?cleos simples que controlam o acesso a mem?ria. Uma implementa??o dessa ideia ? a arquitetura intitulada IPNoSys (Integrated Processing NoC System), que conta com um modelo de programa??o pr?prio e um algoritmo de roteamento que garante a execu??o de todas as instru??es presentes nos pacotes, prevenindo situa??es de deadlock, livelock e starvation. Essa arquitetura apresenta mecanismos de entrada e sa?da, interrup??o e suporte ao sistema operacional. Como prova de conceito foi desenvolvido um ambiente de programa??o e simula??o para esta arquitetura em SystemC, o qual permite a configura??o de v?rios par?metros da arquitetura e obten??o dos resultados para avalia??o da mesma
139

Simula??o de reservat?rios de petr?leo em ambiente MPSoC / Reservoir simulation in a MPSOC environment

Oliveira, Bruno Cruz de 22 May 2009 (has links)
Made available in DSpace on 2014-12-17T15:47:50Z (GMT). No. of bitstreams: 1 BrunoCO.pdf: 708202 bytes, checksum: 3eb4368a0c268064bcd6ad892e1f2c0c (MD5) Previous issue date: 2009-05-22 / The constant increase of complexity in computer applications demands the development of more powerful hardware support for them. With processor's operational frequency reaching its limit, the most viable solution is the use of parallelism. Based on parallelism techniques and the progressive growth in the capacity of transistors integration in a single chip is the concept of MPSoCs (Multi-Processor System-on-Chip). MPSoCs will eventually become a cheaper and faster alternative to supercomputers and clusters, and applications developed for these high performance systems will migrate to computers equipped with MP-SoCs containing dozens to hundreds of computation cores. In particular, applications in the area of oil and natural gas exploration are also characterized by the high processing capacity required and would benefit greatly from these high performance systems. This work intends to evaluate a traditional and complex application of the oil and gas industry known as reservoir simulation, developing a solution with integrated computational systems in a single chip, with hundreds of functional unities. For this, as the STORM (MPSoC Directory-Based Platform) platform already has a shared memory model, a new distributed memory model were developed. Also a message passing library has been developed folowing MPI standard / O constante aumento da complexidade das aplica??es demanda um suporte de hardware computacionalmente mais poderoso. Com a aproxima??o do limite de velocidade dos processadores, a solu??o mais vi?vel ? o paralelismo. Baseado nisso e na crescente capacidade de integra??o de transistores em um ?nico chip surgiram os chamados MPSoCs (Multiprocessor System-on-Chip) que dever?o ser, em um futuro pr?ximo, uma alternativa mais r?pida e mais barata aos supercomputadores e clusters. Aplica??es tidas como destinadas exclusivamente a execu??o nesses sistemas de alto desempenho dever?o migrar para m?quinas equipadas com MPSoCs dotados de dezenas a centenas de n?cleos computacionais. Aplica??es na ?rea de explora??o de petr?leo e g?s natural tamb?m se caracterizam pela enorme capacidade de processamento requerida e dever?o se beneficiar desses novos sistemas de alto desempenho. Esse trabalho apresenta uma avalia??o de uma tradicional e complexa aplica??o da ind?stria de petr?leo e g?s natural, a simula??o de reservat?rios, sob a nova ?tica do desenvolvimento de sistemas computacionais integrados em um ?nico chip, dotados de dezenas a centenas de unidades funcionais. Para isso, um modelo de mem?ria distribu?da foi desenvolvido para a plataforma STORM (MPSoC Directory-Based Platform), que j? contava com um modelo de mem?ria compartilhada. Foi desenvolvida, ainda, uma biblioteca de troca de mensagens para esse modelo de mem?ria seguindo o padr?o MPI
140

Distribution d'une architecture modulaire intégrée dans un contexte hélicoptère / Distribution of an integrated modular architecture in a helicopter context

Bérard-Deroche, Émilie 12 December 2017 (has links)
Les architectures modulaires intégrées (IMA) sont une évolution majeure de l'architecture des systèmes avioniques. Elles permettent à plusieurs systèmes de se partager des ressources matérielles sans interférer dans leur fonctionnement grâce à un partitionnement spatial (zones mémoires prédéfinies) et temporel (ordonnancement statique) dans les processeurs ainsi qu'une réservation des ressources sur les réseaux empruntés. Ces allocations statiques permettent de vérifier le déterminisme général des différents systèmes: chaque système doit respecter des exigences de bout-en-bout dans une architecture asynchrone. Une étude pire cas permet d'évaluer les situations amenant aux limites du système et de vérifier que les exigences de bouten- bout sont satisfaites dans tous les cas. Les architectures IMA utilisés dans les avions centralisent physiquement des modules de calcul puissants dans des baies avioniques. Dans le cadre d'une étude de cas hélicoptère, ces baies ne sont pas envisageables pour des raisons d'encombrement: des processeurs moins puissants, utilisés à plus de 80%, composent ces architectures. Pour ajouter de nouvelles fonctionnalités ainsi que de nouveaux équipements, le souhait est de distribuer la puissance de traitement sur un plus grand nombre de processeurs dans le cadre d'une architecture globale asynchrone. Deux problématiques fortes ont été mises en avant tout au long de cette thèse. La première est la répartition des fonctions avioniques associée à une contrainte d'ordonnancement hors-ligne sur les différents processeurs. La deuxième est la satisfaction des exigences de communication de bout-en-bout, dépendantes de l'allocation et l'ordonnancement des fonctions ainsi que des latences de communication sur les réseaux. La contribution majeure de cette thèse est la recherche d'un compromis entre la distribution des architectures IMA sur un plus grand nombre de processeurs et la satisfaction des exigences de communication de bout-en-bout. Nous répondons à cet enjeu de la manière suivante: - Nous formalisons dans un premier temps un modèle de partitions communicantes tenant en compte des contraintes d'allocation et d'ordonnancement des partitions d'une part et des contraintes de communication de bout-en-bout entre partitions d'autre part. - Nous présentons dans un deuxième temps une recherche exhaustive des architectures valides. Nous proposons l'allocation successive des fonctions avioniques en considérant au même niveau la problématique d'ordonnancement et la satisfaction des exigences de bout-en-bout avec des latences de communication figées. Cette méthode itérative permet de construire des allocations de partitions partiellement valides. La construction des ordonnancements dans chacun des processeurs est cependant une démarche coûteuse dans le cadre d'une recherche exhaustive. - Nous avons conçu dans un troisième temps une heuristique gloutonne pour réduire l'espace de recherche associé aux ordonnancements. Elle permet de répondre aux enjeux de distribution d'une architecture IMA dans un contexte hélicoptère. - Nous nous intéressons dans un quatrième temps à l'impact des latences de communication de bout-en-bout sur des architectures distribuées données. Nous proposons pour celles-ci les choix de réseaux basés sur les latences de communication admissibles entre les différentes fonctions avioniques. Les méthodes que nous proposons répondent au besoin industriel de l'étude de cas hélicoptère, ainsi qu'à celui de systèmes de plus grande taille. / Integrated Modular Architectures (IMA) is a major evolution of avionics systems. A spatial (predefined memory zones) and temporal (off-line scheduling) partitioning as well as communication resources reservation permit several systems not to interfere in this architecture. The determinism of systems is proved thanks to these static allocations: each system must respect end-to-end requirements in an asynchronous architecture. A worst-case study permits to assess the bounds of systems in order to verify that end-to-end requirements are satisfied in all the cases. IMA architectures physically centralize powerful computing resources in avionics bays in aircraft. These aren't feasible in helicopters due to size reasons: powerless processors, at least 80% used, set these architectures. In order to add new functionalities and equipment, the aim is to distribute processing power over a larger number of processors in the context of a globally asynchronous architecture. Two strong issues have been advanced throughout this thesis. The first one is the distribution of avionics functions with an off-line scheduling constraint on the different processors. The second one is the satisfaction of end-to-end requirements, depending on allocation and scheduling of functions as well as communication latencies over the networks. This thesis proposes a trade-off between the distribution of IMA architectures on a larger number of processors and the satisfaction of end-to-end communication requirements. We answer at this topic as follows: - First, we formalize a communicating partitions model based on the partitions allocation and scheduling constraints on the one hand and end-to-end communication constraints on the other hand. - Second, we present an exhaustive search of valid architectures. We introduce a successive allocation of avionics functions considering altogether the scheduling and the satisfaction of end-to-end constraints with fixed communication latencies. This iterative method allows the building of partially valid allocations schemes, but the scheduling search is expensive here. - Third, we create a greedy heuristic to reduce the scheduling search space. It permits to meet the challenges of the distribution of IMA architecture in a helicopter context. - Finally, we focus on the impact of end-to-end communication latencies on given distributed architectures. We define for them the networks based on eligible communication latencies between the different avionics functions. Our methods answer the industrial case study needs as well as bigger size systems needs.

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