Characterizing the Effects of Intermittent Faults on a Processor for Dependability Enhancement Strategy

As semiconductor technology scales into the nanometer regime, intermittent faults have become an increasing threat. This paper focuses on the effects of intermittent faults on NET versus REG on one hand and the implications for dependability strategy on the other. First, the vulnerability characteristics of representative units in OpenSPARC T2 are revealed, and in particular, the highly sensitive modules are identified. Second, an arch-level dependability enhancement strategy is proposed, showing that events such as core/strand running status and core-memory interface events can be candidates of detectable symptoms. A simple watchdog can be deployed to detect application running status (IEXE event). Then SDC (silent data corruption) rate is evaluated demonstrating its potential. Third and last, the effects of traditional protection schemes in the target CMT to intermittent faults are quantitatively studied on behalf of the contribution of each trap type, demonstrating the necessity of taking this factor into account for the strategy

Hard real-time performances in multiprocessor-embedded systems using ASMP-Linux

Multiprocessor systems, especially those based on multicore or multithreaded processors, and new operating system architectures can satisfy the ever increasing computational requirements of embedded systems.ASMP-LINUX is a modified, high responsiveness, open-source hard real-time operating system for multiprocessorsystems capable of providing high real-time performance while maintaining the code simple and not impacting on theperformances of the rest of the system. Moreover, ASMP-LINUX does not require code changing or application recompiling/relinking.In order to assess the performances of ASMP-LINUX, benchmarks have been performed on several hardware platformsand configurations

Towards Efficient Abstractions for Concurrent Consensus

Consensus is an often occurring problem in concurrent and distributed programming. We present a programming language with simple semantics and build-in support for consensus in the form of communicating transactions. We motivate the need for such a construct with a characteristic example of generalized consensus which can be naturally encoded in our language. We then focus on the challenges in achieving an implementation that can efficiently run such programs. We setup an architecture to evaluate different implementation alternatives and use it to experimentally evaluate runtime heuristics. This is the basis for a research project on realistic programming language support for consensus.Comment: 15 pages, 5 figures, symposium: TFP 201

How giving away CMT chip hardware implementations creates value for Sun microsystems

Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2009.Includes bibliographical references (p. 79-81).This thesis uses systems thinking and system dynamics modeling to explore how open source communities such as OpenSPARC can lead to enhancement of the performance of Sun's multithreaded systems and thereby increase its market share by increasing its share of the CMT ecosystem, and the share that CMT systems have within the overall computer server business ecosystem. This study explores Sun's motivation behind its investment in the OpenSPARC community, and explains how OpenSPARC creates value for Sun. The insight into Sun's value creation and capture strategy gained from this study can be generalized and applied to similar companies who are entering a new market where the ecosystem is not yet fully developed. The companies who benefit most from this study are ones which are strategically positioned to disclose relevant knowledge of a critical component within the ecosystem that enables its development without thereby compromising the full potential for value capture within the market. The key findings of this study include: a) Market adoption of multitcore and multithreaded servers is dependent on the rewriting of software applications with parallelization in order to boost the performance of multicore and multithreaded systems. b) The overhaul of these software applications will take the coordination and involvement of all the major players in the computer industry. c) The specific business structure of Sun allows for open sourcing the components of its systems while still gaining revenue on the sale of the system as a whole.(cont.) d) Factors attracting open source developers to write software for a particular platform include a developer's belief that his program will be successful in the market. e) The information leakage to competitors from open sourcing Sun's multithreaded processor implementation does not diminish Sun's value capture of the market. f) The benefits that open source communities can have on market adoption of multicore and multithreaded servers, provided that the disclosure of the chip hardware implementation actually improves the technical performance and economics of the application software. This thesis will explore the reasons that Sun believes the open source community can be a catalyst for the wide-spread adoption of multithreaded processors and multithreaded software required simultaneously by all the major players in the computer industry.by Julie Mitchell.S.M

Acceleration of Spiking Neural Networks on Multicore Architectures

The human cortex is the seat of learning and cognition. Biological scale implementations of cortical models have the potential to provide significantly more power problem solving capabilities than traditional computing algorithms. The large scale implementation and design of these models has attracted significant attention recently. High performance implementations of the models are needed to enable such large scale designs. This thesis examines the acceleration of the spiking neural network class of cortical models on several modern multicore processors. These include the Izhikevich, Wilson, Morris-Lecar, and Hodgkin-Huxley models. The architectures examined are the STI Cell, Sun UltraSPARC T2+, and Intel Xeon E5345. Results indicate that these modern multicore processors can provide significant speed-ups and thus are useful in developing large scale cortical models. The models are then implemented on a 50 TeraFLOPS 336 node PlayStation 3 cluster. Results indicate that the models scale well on this cluster and can emulate 108 neurons and 1010 synapses. These numbers are comparable to the large scale cortical model implementation studies performed by IBM using the Blue Gene/L supercomputer. This study indicates that a cluster of PlayStation 3s can provide an economical, yet powerful, platform for simulating large scale biological models