High-level services for networks-on-chip

Future technology trends envision that next-generation Multiprocessors Systems-on- Chip (MPSoCs) will be composed of a combination of a large number of processing and storage elements interconnected by complex communication architectures. Communication and interconnection between these basic blocks play a role of crucial importance when the number of these elements increases. Enabling reliable communication channels between cores becomes therefore a challenge for system designers. Networks-on-Chip (NoCs) appeared as a strategy for connecting and managing the communication between several design elements and IP blocks, as required in complex Systems-on-Chip (SoCs). The topic can be considered as a multidisciplinary synthesis of multiprocessing, parallel computing, networking, and on- chip communication domains. Networks-on-Chip, in addition to standard communication services, can be employed for providing support for the implementation of system-level services. This dissertation will demonstrate how high-level services can be added to an MPSoC platform by embedding appropriate hardware/software support in the network interfaces (NIs) of the NoC. In this dissertation, the implementation of innovative modules acting in parallel with protocol translation and data transmission in NIs is proposed and evaluated. The modules can support the execution of the high-level services in the NoC at a relatively low cost in terms of area and energy consumption. Three types of services will be addressed and discussed: security, monitoring, and fault tolerance. With respect to the security aspect, this dissertation will discuss the implementation of an innovative data protection mechanism for detecting and preventing illegal accesses to protected memory blocks and/or memory mapped peripherals. The second aspect will be addressed by proposing the implementation of a monitoring system based on programmable multipurpose monitoring probes aimed at detecting NoC internal events and run-time characteristics. As last topic, new architectural solutions for the design of fault tolerant network interfaces will be presented and discussed

Proceedings of the 5th International Workshop on Reconfigurable Communication-centric Systems on Chip 2010 - ReCoSoC\u2710 - May 17-19, 2010 Karlsruhe, Germany. (KIT Scientific Reports ; 7551)

ReCoSoC is intended to be a periodic annual meeting to expose and discuss gathered expertise as well as state of the art research around SoC related topics through plenary invited papers and posters. The workshop aims to provide a prospective view of tomorrow\u27s challenges in the multibillion transistor era, taking into account the emerging techniques and architectures exploring the synergy between flexible on-chip communication and system reconfigurability

Combined Dynamic Thermal Management Exploiting Broadcast-Capable Wireless Network-on-Chip Architecture

With the continuous scaling of device dimensions, the number of cores on a single die is constantly increasing. This integration of hundreds of cores on a single die leads to high power dissipation and thermal issues in modern Integrated Circuits (ICs). This causes problems related to reliability, timing violations and lifetime of electronic devices. Dynamic Thermal Management (DTM) techniques have emerged as potential solutions that mitigate the increasing temperatures on a die. However, considering the scaling of system sizes and the adoption of the Network-on-Chip (NoC) paradigm to serve as the interconnection fabric exacerbates the problem as both cores and NoC elements contribute to the increased heat dissipation on the chip. Typically, DTM techniques can either be proactive or reactive. Proactive DTM techniques, where the system has the ability to predict the thermal profile of the chip ahead of time are more desirable than reactive DTM techniques where the system utilizes thermal sensors to determine the current temperature of the chip. Moreover, DTM techniques either address core or NoC level thermal issues separately. Hence, this thesis proposes a combined proactive DTM technique that integrates both core level and NoC level DTM techniques. The combined DTM mechanism includes a dynamic temperature-aware routing approach for the NoC level elements, and includes task reallocation heuristics for the core level elements. On-chip wireless interconnects recently envisioned to enable energy-efficient data exchange between cores in a multicore chip will be used to provide a broadcast-capable medium to efficiently distribute thermal control messages to trigger and manage the DTM. Combining the proactive DTM technique with on-chip wireless interconnects, the on-chip temperature is restricted within target temperatures without significantly affecting the performance of the NoC based interconnection fabric of the multicore chip

Resource-aware Programming in a High-level Language - Improved performance with manageable effort on clustered MPSoCs

Bis 2001 bedeutete Moores und Dennards Gesetz eine Verdoppelung der Ausführungszeit alle 18 Monate durch verbesserte CPUs. Heute ist Nebenläufigkeit das dominante Mittel zur Beschleunigung von Supercomputern bis zu mobilen Geräten. Allerdings behindern neuere Phänomene wie "Dark Silicon" zunehmend eine weitere Beschleunigung durch Hardware. Um weitere Beschleunigung zu erreichen muss sich auch die Soft­ware mehr ihrer Hardware Resourcen gewahr werden. Verbunden mit diesem Phänomen ist eine immer heterogenere Hardware. Supercomputer integrieren Beschleuniger wie GPUs. Mobile SoCs (bspw. Smartphones) integrieren immer mehr Fähigkeiten. Spezialhardware auszunutzen ist eine bekannte Methode, um den Energieverbrauch zu senken, was ein weiterer wichtiger Aspekt ist, welcher mit der reinen Geschwindigkeit abgewogen werde muss. Zum Beispiel werden Supercomputer auch nach "Performance pro Watt" bewertet. Zur Zeit sind systemnahe low-level Programmierer es gewohnt über Hardware nachzudenken, während der gemeine high-level Programmierer es vorzieht von der Plattform möglichst zu abstrahieren (bspw. Cloud). "High-level" bedeutet nicht, dass Hardware irrelevant ist, sondern dass sie abstrahiert werden kann. Falls Sie eine Java-Anwendung für Android entwickeln, kann der Akku ein wichtiger Aspekt sein. Irgendwann müssen aber auch Hochsprachen resourcengewahr werden, um Geschwindigkeit oder Energieverbrauch zu verbessern. Innerhalb des Transregio "Invasive Computing" habe ich an diesen Problemen gearbeitet. In meiner Dissertation stelle ich ein Framework vor, mit dem man Hochsprachenanwendungen resourcengewahr machen kann, um so die Leistung zu verbessern. Das könnte beispielsweise erhöhte Effizienz oder schnellerer Ausführung für das System als Ganzes bringen. Ein Kerngedanke dabei ist, dass Anwendungen sich nicht selbst optimieren. Stattdessen geben sie alle Informationen an das Betriebssystem. Das Betriebssystem hat eine globale Sicht und trifft Entscheidungen über die Resourcen. Diesen Prozess nennen wir "Invasion". Die Aufgabe der Anwendung ist es, sich an diese Entscheidungen anzupassen, aber nicht selbst welche zu fällen. Die Herausforderung besteht darin eine Sprache zu definieren, mit der Anwendungen Resourcenbedingungen und Leistungsinformationen kommunizieren. So eine Sprache muss ausdrucksstark genug für komplexe Informationen, erweiterbar für neue Resourcentypen, und angenehm für den Programmierer sein. Die zentralen Beiträge dieser Dissertation sind: Ein theoretisches Modell der Resourcen-Verwaltung, um die Essenz des resourcengewahren Frameworks zu beschreiben, die Korrektheit der Entscheidungen des Betriebssystems bezüglich der Bedingungen einer Anwendung zu begründen und zum Beweis meiner Thesen von Effizienz und Beschleunigung in der Theorie. Ein Framework und eine Übersetzungspfad resourcengewahrer Programmierung für die Hochsprache X10. Zur Bewertung des Ansatzes haben wir Anwendungen aus dem High Performance Computing implementiert. Eine Beschleunigung von 5x konnte gemessen werden. Ein Speicherkonsistenzmodell für die X10 Programmiersprache, da dies ein notwendiger Schritt zu einer formalen Semantik ist, die das theoretische Modell und die konkrete Implementierung verknüpft. Zusammengefasst zeige ich, dass resourcengewahre Programmierung in Hoch\-sprachen auf zukünftigen Architekturen mit vielen Kernen mit vertretbarem Aufwand machbar ist und die Leistung verbessert

High level design and control of adaptive multiprocessor system-on-chips

The design of modern embedded systems is getting more and more complex, as more func- tionality is integrated into these systems. At the same time, in order to meet the compu- tational requirements while keeping a low level power consumption, MPSoCs have emerged as the main solutions for such embedded systems. Furthermore, embedded systems are be- coming more and more adaptive, as the adaptivity can bring a number of benefits, such as software flexibility and energy efficiency. This thesis targets the safe design of such adaptive MPSoCs. First, each system configuration must be analyzed concerning its functional and non- functional properties. We present an abstract design and analysis framework, which allows for faster and cost-effective implementation decisions. This framework is intended as an intermediate reasoning support for system level software/hardware co-design environments. It can prune the design space at its largest, and identify candidate design solutions in a fast and efficient way. In the framework, we use an abstract clock-based encoding to model system behaviors. Different mapping and scheduling scenarios of applications on MPSoCs are analyzed via clock traces representing system simulations. Among properties of interest are functional behavioral correctness, temporal performance and energy consumption. Second, the reconfiguration management of adaptive MPSoCs must be addressed. We are specially interested in MPSoCs implemented on reconfigurable hardware architectures (i.e., FPGA fabrics), which provide a good flexibility and computational efficiency for adap- tive MPSoCs. We propose a general design framework based on the discrete controller syn- thesis (DCS) technique to address this issue. The main advantage of this technique is that it allows the automatic controller synthesis w.r.t. a given specification of control objectives. In the framework, the system reconfiguration behavior is modeled in terms of synchronous parallel automata. The reconfiguration management computation problem w.r.t. multiple objectives regarding e.g., resource usages, performance and power consumption is encoded as a DCS problem. The existing BZR programming language and Sigali tool are employed to perform DCS and generate a controller that satisfies the system requirements. Finally, we investigate two different ways of combining the two proposed design frame- works for adaptive MPSoCs. Firstly, they are combined to construct a complete design flow for adaptive MPSoCs. Secondly, they are combined to present how the designed run-time manager by the second framework can be integrated into the first framework so that high level simulations can be performed to assess the run-time manager.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 plus rapide et plus 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 abstrait 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 de hardware (ex. FPGA tissus) qui offrent une bonne flexibilité et une efficacité de calcul pour les MPSoCs adaptatifs. Nous proposons un cadre général de conception basésur la technique de la synthèse de contrôleurs discrets (SCD) pour résoudre ce problème. L’avantage principal de cette technique est qu'elle permet une synthèse d'un contrôleur automatique vis-à-vis d’une spécification donnée 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 vis-à-vis de multiples objectifs concernant, par exemple, les usages des ressources, la performance et la consommation d’énergie est codé comme un problème de SCD . Le langage de programmation BZR existant et l’outil Sigali sont employés pour effectuer SCD 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 gestionnaire d'exécution conçu dans le second cadre peut être intégré dans le premier cadre de sorte que les simulations de haut niveau peuvent être effectuées pour évaluer le gestionnaire d'exécution

Design Space Exploration and Resource Management of Multi/Many-Core Systems

The increasing demand of processing a higher number of applications and related data on computing platforms has resulted in reliance on multi-/many-core chips as they facilitate parallel processing. However, there is a desire for these platforms to be energy-efficient and reliable, and they need to perform secure computations for the interest of the whole community. This book provides perspectives on the aforementioned aspects from leading researchers in terms of state-of-the-art contributions and upcoming trends

Dynamic Resource Allocation in Embedded, High-Performance and Cloud Computing

The availability of many-core computing platforms enables a wide variety of technical solutions for systems across the embedded, high-performance and cloud computing domains. However, large scale manycore systems are notoriously hard to optimise. Choices regarding resource allocation alone can account for wide variability in timeliness and energy dissipation (up to several orders of magnitude). Dynamic Resource Allocation in Embedded, High-Performance and Cloud Computing covers dynamic resource allocation heuristics for manycore systems, aiming to provide appropriate guarantees on performance and energy efficiency. It addresses different types of systems, aiming to harmonise the approaches to dynamic allocation across the complete spectrum between systems with little flexibility and strict real-time guarantees all the way to highly dynamic systems with soft performance requirements. Technical topics presented in the book include: Load and Resource Models Admission Control Feedback-based Allocation and Optimisation Search-based Allocation Heuristics Distributed Allocation based on Swarm Intelligence Value-Based Allocation Each of the topics is illustrated with examples based on realistic computational platforms such as Network-on-Chip manycore processors, grids and private cloud environments.Note.-- EUR 6,000 BPC fee funded by the EC FP7 Post-Grant Open Access Pilo