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This thesis presents the design and evaluation of an object-oriented (OO) operating system kernel for real-time embedded systems based on dataflow architecture. Dataflow is a software architecture that is well suited to applications that involve signal flows and value transformations. Typically, these systems comprise numerous processes with heavy inter-process communications. The dataflow style has been adopted for the control software for PEBB (Power Electronic Building Block) systems by the Center for Power Electronic Systems (CPES), Virginia Tech., which is involved in a research effort to modularize and standardize power electronic components. The goal of our research is to design and implement an efficient object-oriented kernel for the PEBB system and compare its performance vis-à-vis that of a non-OO kernel. It presents strategies for efficient OO design and a discussion of how OO performance issues can be ameliorated. We conclude the thesis with an evaluation of the advantages gained by using the OO paradigm both from the standpoint of the classically cited advantages of OO programming and other crucial aspects. / Master of Science

De nos jours, des processeurs à mémoire partagée cohérente ayant jusqu’à 100 coresintégrés sur la même puce sont une réalité et des processeurs many-cores ayant plusieurs centaines, voire, un millier de cores sont à prévoir prochainement.Dans ces architectures, la question de la localité du trafic lié aux miss decaches L1 (data, instruction et TLB) est primordiale à la fois pour passer àl’échelle et pour réduire la consommation électrique (énergie consommée par bittransféré). Notre thèse est que : (i) la gestion de la localité des accès mémoiredoit être prise en compte au niveau du noyau du système d’exploitation et elle doitêtre effectuée d’une manière transparente aux applications utilisateur; et (ii) les noyaux monolithiques actuels sont incapables de renforcer la localité des accès mémoire des threads d’une même application parallèle, car la notion de threadsdans ces noyaux est intrinsèquement inadaptée pour les processeurs many-cores.Par conséquent, nous pensons que la démarche suivie jusqu’à présent pour faireévoluer les noyaux monolithiques n’est pas suffisante et qu’il est impératif demettre la question de la localité des accès mémoire au centre de cette évolution.Pour prouver notre thèse, nous avons conçu et réalisé ALMOS (Advanced Locality Management Operating System), un système d’exploitation expérimental à base de noyau monolithique distribué. ALMOS dispose d’un nouveau concept de thread, nommé Processus Hybrides. Il permet à son noyau de renforcer, d’une manière transparente, la localité des accès mémoire liés à l'exécution de chaque thread. La gestion des ressources (cores et mémoires physiques) dans le noyau d’ALMOS est distribuée renforçant la localité des accès mémoire lors de la réalisation des services systèmes. La prise de décision concernant l’allocation mémoire, le placement des tâches et l’équilibrage de charge dans le noyau d’ALMOS est décentralisée, multi-critères et sans prise de verrou. Elle repose sur une infrastructure distribuée coordonnant d’une manière scalable l’accès aux ressources.En utilisant le prototype virtuel précis au cycle et au bit près du processeur many-core TSAR, nous avons expérimentalement démontré que : (i) les performances(scalabilité et temps d’exécution) du schéma d'ordonnancement distribué du noyaud’ALMOS sur 256 cores dépassent celles des noyaux monolithiques existants; (ii) la réalisation répartie de l’appel système fork permet de passer à l’échellece service système sur 512 cores; (iii) le coût de la mise à jour de l’infrastructure distribué de prise de décisions du noyau d’ALMOS ne nécessiteque 0.05% de la puissance de calcul totale du processeur TSAR; (iv) les performances(scalabilité, temps d’exécution et trafic distant) de la stratégie d’affinitémémoire du noyau d’ALMOS, nommé Auto-Next-Touch, dépassent celles des deuxstratégies First-Touch et Interleave sur 64 cores; (v) le modèle de processushybrides d’ALMOS permet de passer à l’échelle deux applications hautementmulti-threads existantes sur 256 cores et une troisième sur 1024 cores; et enfin (vi) le couple ALMOS/TSAR (64 cores) offre systématiquement une bien meilleure scalabilité que le couple Linux/AMD (Interlagos 64 cores) pour 8 applications de classe HPC et traitement d’images. / Nowadays, single-chip cache-coherent many-core processors having up to 100 coresare a reality. Many-cores with hundreds or even a thousand of cores are planned in the near future. In theses architectures, the question of the locality of L1 cache-miss related traffic (data, instruction and TLB) is essential for both scalability and power consumption (energy by moved bit). Our thesis is that: (i) handling the locality of memory accesses should be done at kernel level of an operating system in a transparent manner to user applications; and (ii) the current monolithic kernels are not able to enforce the locality of memory accesses of multi-threaded applications, because the concept of thread in these kernels is inherently unsuitable for many-core processors. Therefore, we believe that the evolution approach of monolithic kernels undertaken until now is insufficient and it is imperative to put the question of the locality of memory accesses in the heart of this evolution.To prove our thesis, we designed and implemented ALMOS (Advanced Locality Management Operating System), an experimental operating system based on a distributed monolithic kernel. ALMOS has a new concept of thread, called Hybrid Process. It allows its kernel to enforce the locality of memory accesses of each thread. The resources (cores and physical memory) management in ALMOS's kernel is distributed enforcing the locality of memory accesses when performing system services. Decision making regarding memory allocation, tasks placement and load balancing in ALMOS's kernel is decentralized, multi-criteria and without locking. It is based on a distributed infrastructure coordinating, in a scalable manner, the accesses to resources.Using the cycle accurate and bit accurate virtual prototype of TSAR many-core processor, we experimentally demonstrated that: (i) performance (scalability and execution time) on 256 cores of the distributed scheduling scheme of ALMOS's kernel outperform those of the shared scheduling scheme found in existing monolithic kernels; (ii) distributed realization of the fork system call enables this system service to scale on 512 cores; (iii) updating the distrusted decision-making infrastructure of ALMOS's kernel costs just 0.05 % of the total computing power of TSAR processor; (iv) performance (scalability, execution time and remote traffic) of memory affinity strategy of ALMOS's kernel, called Auto-Next-Touch, outperform those of two existing strategies First-Touch and Interleave on 64 cores; (v) concept of Hybrid Process of ALMOS's kernel scales up two existing highly multi-threads applications on 256 cores and a third one on 1024 cores; and finally (vi) the couple ALMOS/TSAR (64 cores) gives systematically much better scalability than the couple Linux/AMD (Interlagos 64 cores) for 8 multi-threads applications belonging to HPC and image processing domains.

Es wird ein Konzept für ein zukünftiges Betriebssystem vorgestellt, das den Anforderungen und Möglichkeiten der zunehmenden Vernetzung von Rechnern und anderen Endgeräten Rechnung trägt. Es erweitert den bekannten Grundgedanken, mit Hilfe von Peer-to-Peer Technologien explorierbare virtuelle 3D-Landschaften zu erzeugen, ohne dabei von einem zentralen Anbieter abhängig zu sein. Es soll Nutzern die Möglichkeit bieten, das Serviceangebot im Internet ohne Einschränkungen zu durchsuchen und dabei anhand eigener semantischer Kriterien die für sie interessanten Services hervorzuheben. Über Parameter der Darstellung sollen Netzwerkeigenschaften, die für den Nutzer von Belang sein können, intuitiv erfassbar sein. Das System beinhaltet darüber hinaus Möglichkeiten zur Last- und Verkehrsbalancierung. In diesem Artikel werden Anforderungen an die zu Grunde liegende Infrastruktur und die grafische Benutzeroberfläche definiert, erste Skizzen des zukünftigen Systems vorgestellt und die weiteren Schritte bis zur Verwirklichung eines Prototyps diskutiert.

Es wird ein Konzept für ein zukünftiges Betriebssystem vorgestellt, das den Anforderungen und Möglichkeiten der zunehmenden Vernetzung von Rechnern und anderen Endgeräten Rechnung trägt. Es erweitert den bekannten Grundgedanken, mit Hilfe von Peer-to-Peer Technologien explorierbare virtuelle 3D-Landschaften zu erzeugen, ohne dabei von einem zentralen Anbieter abhängig zu sein. Es soll Nutzern die Möglichkeit bieten, das Serviceangebot im Internet ohne Einschränkungen zu durchsuchen und dabei anhand eigener semantischer Kriterien die für sie interessanten Services hervorzuheben. Über Parameter der Darstellung sollen Netzwerkeigenschaften, die für den Nutzer von Belang sein können, intuitiv erfassbar sein. Das System beinhaltet darüber hinaus Möglichkeiten zur Last- und Verkehrsbalancierung. In diesem Artikel werden Anforderungen an die zu Grunde liegende Infrastruktur und die grafische Benutzeroberfläche definiert, erste Skizzen des zukünftigen Systems vorgestellt und die weiteren Schritte bis zur Verwirklichung eines Prototyps diskutiert.

Christiane is a 7 meter sailing vessel and a 1:30 scale model of Oceanbird, a wind powered car carrier planned to be launched by the year 2024. The model is used for design validation and to research control algorithms. However, the development of new algorithms is limited to the microcontrollers used, which are not able to run resource intense applications. Furthermore, there is no easy way for new computational nodes to interact with the vessels system. In this thesis, a high-level, easy to use, interface was proposed, designed and implemented. This was done by identifying the the requirements and limitations of the project and examining the system to find a suitable solution. The two biggest limitations found were that the solution had to include a single-board computer and that the implementation could not drastically alter the system architecture of the model. The implementation included a single-board computer being added on top of the models architecture which publishes all gathered sensor data and actuator commands on a robotics operating system interface. The interface was an immediate improvement to the usability of the vessel since it allows for graphical presentation of gathered data in real time. / Christiane är en 7 meter lång segellfarkost och en modell i skala 1:30 av Oceanbird, ett vinddrivet lastfartyg för fordon som är planerad att sjösättas år 2024. Modellen används för att validera designen samt för forskning kring kontrollalgoritmer. Utvecklingen av nya algoritmer är dessvärre begränsad till systemets mikrokroller, vilka inte klarar av att köra resursintensiva applikationer. Det finns inte heller något enkelt sätt för nya beräkningsnoder att interagera med båtens system. Denna rapport föreslår ett högnivå-gränssnitt till modellen som är enkelt att använda och presenterar en implementation av det som underlättar framtida forskning. Detta gjordes genom att först identifiera projektets krav och begränsningar samt genom att undersöka modellens system för att hitta en lämplig lösning. De två största funna begränsningarna var att lösningen var tvungen att inkludera en enkortsdator och att implementationen inte fick innebära några större förändringar av modellens system-arkitektur. Implementationen bestod av att en enkortsdator lades till ovanpå modellens arkitektur som publicerar all samlad sensordata och alla kommandon för ställdon på ett robotics operating system gränssnitt. Gränssnittet gav en direkt förbättring av fartygets användarvänlighet då det möjliggjorde grafisk presentation av den samlade datan i realtid.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / In this paper we describe the design of the REAL/STAR 2000 system, a highperformance real-time computer for telemetry applications. The REAL/STAR 2000 is a symmetric, tightly-coupled multiprocessor, optimized for real-time processing. The system provides a high level of scalability and flexibility by supporting three configurations: single, dual, and quad processor configurations, based on Motorola 88100 RISC processors. The system runs the multiprocessor REAL/IX operating system, a real-time implementation of the AT&T UNIX System V. It compiles with BCS and OCS standards, meets the POSIX 1003.1 standard, and has the current functionality of the emerging POSIX 1003.4 real-time standard. The REAL/STAR 2000 promotes an open system approach to real-time computing by supporting major industry standards. Benchmark results are also presented in the paper.

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The Advanced Telemetry Processing System (ATPS) is the result of a joint development project between Harris Corporation and Veda Systems, Incorporated. The mission of the development team was to produce a high-performance, cost-effective, supportable telemetry system; one that would utilize commercial-off-the-shelf (COTS) hardware and software, thereby eliminating costly customization typically required for range and telemetry applications. A critical element in the 'cost-effective, supportable' equation was the ability to easily incorporate system performance upgrades as well as future hardware and software technology advancements. The ATPS combines advanced hardware and software technology that includes a high-speed, top-down data management environment; a mature man-machine interface; a B1-level Trusted operating system and network; and stringent real-time multiprocessing capabilities into a single, fully integrated, 'open' platform. In addition, the system incorporates a unique direct memory transfer feature that allows incoming data to pass directly into local memory space where it can be displayed and analyzed, thereby reducing I/O bottleneck and freeing processors for other specialized tasks.

This thesis compares the file organization techniques that are implemented on two different types of computer systems, the large-scale and the small-scale. File organizations from representative computers in each class are examined in detail: the IBM System/370 (OS/370) and the Harris 1600 Distributed Processing System with the Extended Communications Operating System (ECOS). In order to establish the basic framework for comparison, an introduction to file organizations is presented. Additionally, the functional requirements for file organizations are described by their characteristics and user demands. Concluding remarks compare file organization techniques and discuss likely future developments of file systems.