Fault Tolerant Systems Israel Koren, C. Mani Krishna
2007, 2010, 2010-07-19T00:00:00, 2010-07-19, c2007
eBook
There are many applications in which the reliability of the overall system must be far higher than the reliability of its individual components. In such cases, designers devise mechanisms and ...architectures that allow the system to either completely mask the effects of a component failure or recover from it so quickly that the application is not seriously affected. This is the work of fault-tolerant designers and their work is increasingly important and complex not only because of the increasing number of “mission critical” applications, but also because the diminishing reliability of hardware means that even systems for non-critical applications will need to be designed with fault-tolerance in mind. Reflecting the real-world challenges faced by designers of these systems, this book addresses fault tolerance design with a systems approach to both hardware and software. No other text on the market takes this approach, nor offers the comprehensive and up-to-date treatment the authors provide. Students, designers and architects of high performance processors will value this comprehensive overview of the field.
Intelligent transportation systems (ITS) achieve improved throughput and safety using periodic vehicle-to-vehicle and vehicle-to-infrastructure wireless communication. Vehicles use pseudonyms which ...are frequently exchanged to protect against eavesdroppers using such messages for tracking. Such exchange takes place in mix zones where all wireless transmission is forbidden in order to prevent matching the new pseudonym of a vehicle with its previous one. Mix zones are not free: in addition to infrastructure cost, they impose a cost in terms of reduced vehicular throughput and disruption to vehicular communication. We present a scheme to manage traffic within a mix zone to make it more resilient to attacks against privacy. Second, we introduce a heuristic to place mix zones appropriately so that the gain in privacy is balanced against the cost in reduced throughput. We evaluate our schemes assuming a powerful attacker who has access to all wireless transmissions and uses a simple but powerful machine learning algorithm. Our algorithms are evaluated using detailed traffic simulations in two US cities: New York, NY, and Cambridge, MA.
Cool-cache for hot multimedia Unsal, O.S.; Ashok, R.; Koren, I. ...
Proceedings of the annual International Symposium on Microarchitecture,
2001
Conference Proceeding, Journal Article
We claim that the unique characteristics of multimedia applications dictate media-sensitive architectural and compiler approaches to reduce the power consumption of the data cache. Our motivation is ...exploring energy savings for real-time multimedia workloads without sacrificing performance. In this paper, we present two complementary media-sensitive energy-saving techniques that leverage static information. While our first technique is applicable to existing architectures, in our second technique we adopt a more radical approach and propose a new caching architecture by re-evaluating the architecture-compiler interface. Our experiments show that substantial energy savings are possible in the data cache. Across a wide range of cache and architectural configurations we obtain up to 77% energy savings, while the performance varies from 14% improvement to 4% degradation depending on the application.
Simultaneous multithreading (SMT) increases processor throughput by allowing parallel execution of several threads. However, fully sharing processor resources may cause resource monopolization by a ...single thread or other misallocations, resulting in overall performance degradation. Static resource partitioning techniques have been suggested, but are not as effective as dynamic ones since program behavior does change over the course of its execution. In this paper, we propose an Adaptive Resource Partitioning Algorithm (ARPA) that dynamically assigns resources to threads according to changes in thread behavior. ARPA analyzes the resource usage efficiency of each thread in a given time period and assigns more resources to threads which can use them more efficiently. Its purpose is to improve the efficiency of resource utilization, thereby improving overall instruction throughput. Our simulation results on a set of 42 multiprogramming workloads show that ARPA outperforms the traditional fetch policy ICOUNT by 55.8 percent with regard to overall instruction throughput and achieves a 33.8 percent improvement over Static Partitioning. It also outperforms the current best dynamic resource allocation technique, Hill-climbing, by 5.7 percent. Considering fairness accorded to each thread, ARPA attains 43.6, 18.5, and 9.2 percent improvements over ICOUNT, Static Partitioning, and Hill-climbing, respectively, using a common fairness metric. We also explore the energy efficiency of dynamically controlling the number of powered-on reorder buffer entries for ARPA. Compared with ARPA, our energy-aware resource partitioning algorithm achieves 10.6 percent energy savings, while the performance loss is negligible.
Emerging nano-device based architectures are expected to experience high defect rates associated with the manufacturing process. In this paper, we introduce a novel built-in heterogeneous ...fault-tolerance scheme, which incorporates redundant circuitry into the design to provide fault tolerance. A thorough analysis of the new scheme was carried out for various system level metrics. The implementation and analysis were carried out on WISP-0, a stream processor implemented on the Nanoscale Application Specific Integrated Circuits (NASIC) fabric. We show that intelligent assignment of redundancy levels and nanoscale-voting strategies across WISP-0 greatly improves area, effective yield and performance for the nano-processor. The new scheme outperforms homogeneous schemes for a defect range of 3% to 9.75% where the metric used is the product of performance and effective yield.
Simultaneous Multithreading (SMT) increases processor throughput by allowing the parallel execution of several threads. However, fully sharing processor resources may cause resource monopolization by ...a single thread or other misallocations, resulting in overall performance degradation. Static resource partitioning techniques have been suggested, but are not as effective as dynamically controlling the resource usage of each thread since program behavior does change during its execution. In this paper, we propose an Adaptive Resource Partitioning Algorithm (ARPA) that dynamically assigns resources to threads according to thread behavior changes. ARPA analyzes the resource usage efficiency of each thread in a time period and assigns more resources to threads which can use them in a more efficient way. The purpose of ARPA is to improve the efficiency of resource utilization, thereby improving overall instruction throughput. Our simulation results on a set of 42 multiprogramming workloads show that ARPA outperforms the traditional fetch policy ICOUNT by 55.8% with regard to overall instruction throughput and achieves a 33.8% improvement over Static Partitioning. It also outperforms the current best dynamic resource allocation technique, Hill-climbing, by 5.7%. Considering fairness accorded to each thread, ARPA attains 43.6%, 18.5% and 9.2% improvements over ICOUNT, Static Partitioning and Hill-climbing, respectively, using a common fairness metric.
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