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A Dependability Model for TMR system

International Journal of Automation and computing 2012年第3期9卷 315-324页

作者： Peng, Jun-Jie Liu, Yan-Ping Chen, Yuan-Yuan School of Computer Engineering and Science Shanghai University Shanghai 200072 China Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

Much research has been done on the dependability evaluation of computer systems. However, much of this is gone no further than study of the fault coverage of such systems, with little focus on the relationship between fault coverage and overall system dependability. In this paper, a Markovian dependability model for triple-modular-redundancy (TMR) system is presented. Having fully considered the effects of fault coverage, working time, and constant failure rate of single module on the dependability of the target TMR system, the model is built based on the stepwise degradation strategy. Through the model, the relationship between the fault coverage and the dependability of the system is determined. What is more, the dependability of the system can be dynamically and precisely predicted at any given time with the fault coverage set. This will be of much benefit for the dependability evaluation and improvement, and be helpful for the system design and maintenance.

关键词： Dependability Markovian model coverage triple-modular-redundancy (TMR) failure rate.

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Integrating DBMSs as a read-only execution layer into Hadoop

Integrating DBMSs as a read-only execution layer into Hadoop

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11th International Conference on Parallel and Distributed Computing, Applications and Technologies, PDCAT 2010

作者： An, Mingyuan Wang, Yang Wang, Weiping Sun, Ninghui Key Laboratory of Computer System and Architecture Graduate University of Chinese Academy of Sciences Chinese Academy of Sciences Beijing China Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing China

ISBN: (纸本)9780769542874

To obtain the efficiency of DBMS, HadoopDB combines Hadoop and DBMS, and claims the superiority over Hadoop in terms of performance. However, the approach of HadoopDB is simply putting MapReduce onto unmodified single-machined DBMSs which has several obvious weaknesses. In essence, HadoopDB is a parallel DBMS with fault tolerance, which incurs unnecessary overhead due to the DBMS legacy. Instead of augmenting DBMS with Hadoop techniques, we propose a new system architecture integrating modified DBMS engines as a read-only execution layer into Hadoop, where DBMS plays a role of providing efficient readonly operators rather than managing the data. Besides the obtained efficiency from DBMS engine, there are other advantages. The modified DBMS engine is able to directly process data from the HDFS (Hadoop Distributed File system) files at the block level, which means that the data replication can be handled by HDFS naturally, and the blocklevel parallelism is easily achieved. The global index access mechanism is added according to the MapReduce paradigm. The data loading speed is also guaranteed by directly writing the data into HDFS with simplified logic. Experiments show that our system outperforms both original Hadoop and HadoopDB styled system. © 2010 IEEE.

关键词： Database systems

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Computation pattern driven reuse of manual optimizations for GPGPUs

Computation pattern driven reuse of manual optimizations for...

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2011 12th International Conference on Parallel and Distributed Computing, Applications and Technologies, PDCAT 2011

作者： Xu, Shixiong Han, Dongni Chen, Li Key Laboratory of Computer System and Architecture Institute of Computing Technology University of Chinese Beijing China

ISBN: (纸本)9780769545646

The wide application of General Purpose Graphic Processing Units (GPGPUs) results in large manual efforts on porting and optimizing algorithms on them. However, most existing automatic ways of generating GPGPU code fail to conduct optimization strategies regarding a specific computation and to reuse constantly evolving manual optimizations. In this paper, we present a computation pattern driven approach for computation-specific GPGPU code generation and optimization, which in turn reuses manual optimizations to a certain extent. We suggest language extensions to OpenMP, high-level data structure attributes, in order to assist the process of computation pattern matching and to help give users intuitive performance tuning parameters in the view of data structure attributes. We illustrate the feasibility of this approach through three important computation dwarfs, which are dense matrix, sparse matrix, and structured mesh computation in scientific computing. We also build a prototype OpenMP-to-CUDA translator that consists of computation pattern recognition and code template instantiation. The experimental results demonstrate the performance benefits of computation pattern driven method. To our best knowledge, it is the first work on reusing manual optimizations for GPGPUs with computation pattern driven approach. © 2011 IEEE.

关键词： Data structures

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An efficient error control scheme for chip-to-chip optical interconnects

An efficient error control scheme for chip-to-chip optical i...

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2007 IEEE International Symposium on Circuits and systems, ISCAS 2007

作者： Jun, Wang Ge, Zhang Weiwu, Hu Key Laboratory of Computer System and Architecture Institute of Computing Technology CAS Beijing 100080 China

As the gap between processing capability and bandwidth requirement of microprocessor increases, optical interconnects are used more and more widely in chip-to-chip data links. Trade-offs are made among latency, area, power consumption and reliability in the high frequency interconnect system in which error control schemes are always implemented to make it tolerate PER (packet error rate). In this paper, a scalable system for chip-to-chip optical interconnects is proposed and different types of error control schemes are compared using 90nm CMOS process. The goals are set to low latency, small area and low power consumption as well as acceptable MTTF (mean time to failure) for USR (ultra-short-reach) with very low BER (bit error rate). After that the ECS-HC based system is picked out and validated based on FPGA and 4.25Gbps 850nm optical transceivers. © 2007 IEEE.

关键词： Error correction

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A parallel algorithm for computing betweenness centrality

A parallel algorithm for computing betweenness centrality

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38th International Conference on Parallel Processing, ICPP-2009

作者： Tan, Guangming Tu, Dengbiao Sun, Ninghui Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Science Beijing China

ISBN: (纸本)9780769538020

In this paper we present a multi-grained parallel algorithm for computing betweenness centrality, which is extensively used in large-scale network analysis. Our method is based on a novel algorithmic handling of access conflicts for a CREW PRAM algorithm. We propose a proper data-processor mapping, a novel edge-numbering strategy and a new triple array data structure recording the shortest path for eliminating conflicts to access the shared memory. The algorithm requires O(n + m) space and O(nm/p ) ( or O(nm+n2logn /p )) time for unweighted (or weighted) graphs, and it is a work-optimal CREW PRAM algorithm. On current multi-core platforms, our algorithm outperforms the previous algorithm by 2-3 times. © 2009 IEEE.

关键词： Parallel algorithms

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Software and hardware cooperate for 1-D FFT algorithm optimization on multicore processors

Software and hardware cooperate for 1-D FFT algorithm optimi...

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IEEE 9th International Conference on computer and Information Technology, CIT 2009

作者： Zhou, Yongbin Zhang, Junchao Fan, Dongrui Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing China

ISBN: (纸本)9780769538365

Multicore architecture is becoming a promise to keep Moore's Law and brings a revolution in both research and industry which results new design space for software and architecture. Fast Fourier Transform (FFT), computing intensive and bandwidth intensive, is one of the most popular and important applications in the world. Compared with the computing resource on multicore architecture, the on-chip memory resource is much more expensive because of the limitation of physical chip size. Efficient implementation of FFT algorithm on multicore with good scalability is a challenge for both software and hardware developers. In this paper, supported by the Godson-T architecture, an optimized implementation of 1-D FFT has been developed with matrix transpose conceal and computation/communication overlapping, which achieve more than 30% performance improvement as well as almost 1/3 L2 cache consumption reduce comparing with the base six-step FFT. The limitation of scalability is also analyzed and the conclusion is that on Godson-T when frequency and simultaneous data access happen, the limited access bandwidth of L2 cache is the bottleneck and result in the longer on-chip network latency. © 2009 IEEE.

关键词： Fast Fourier transforms

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Circuit implementation of floating point range reduction for trigonometric functions

Circuit implementation of floating point range reduction for...

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2007 IEEE International Symposium on Circuits and systems, ISCAS 2007

作者： Xuehai, Qian Hao, Zhang Jingang, Yang He, Huang Junchao, Zhang Dongrui, Fan Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing China

Range reduction is important in evaluating trigonometric functions but not enough work is done in relation to the hardware implementation of it. A hardware floating point range reduction implementation is presented. The whole reduction is divided into two steps;the first is based on Double-Residue modular range reduction method and the second adopts on a novel method described in this paper. The latter one can reduce the argument to an arbitrary range and provides the number of times that range constant contained in the argument It has been synthesized using 0.13 um library to achieve an approximately 700 MHz operation frequency. © 2007 IEEE.

关键词： Digital circuits

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GenerOS: An asymmetric operating system kernel for multi-core systems

GenerOS: An asymmetric operating system kernel for multi-cor...

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24th IEEE International Parallel and Distributed Processing Symposium, IPDPS 2010

作者： Yuan, Qingbo Zhao, Jianbo Chen, Mingyu Sun, Ninghui Key Laboratory of Computer System and Architecture Institute of Compute Technology Chinese Academy of Sciences Beijing China

ISBN: (纸本)9781424464432

Due to complex abstractions implemented over shared data structures protected by locks, conventional symmetric multithreaded operating system kernel such as Linux is hard to achieve high scalability on the emerging multi-core architectures, which integrate more and more cores on a single die. This paper presents GenerOS - a general asymmetric operating system kernel for multi-core systems. In principal, GenerOS partitions processing cores into application core, kernel core and interrupt core, each of which is dedicated to a specified function. In implementation, we conduct a delicate modification to Linux kernel and provide the same interface as Linux kernel so that GenerOS is compatible with legacy applications. The better performance of GenerOS mainly benefits from: (1) Applications run on their own cores with minimal interrupt and kernel support;(2) Every kernel service is encapsulated into a serial process so that there will be fewer contentions than conventional symmetric kernel;(3) A slim schedule policy is used in the kernel core to support schedule between system calls with low overhead. Experiments with two typical workloads on 16-core AMD machine show that GenerOS behaves better than original Linux kernel when there are more processing cores (19.6% for TPCH using oracle database management system and 42.8% for httperf using apache web server). © 2010 IEEE.

关键词： Linux

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Virtual resource monitoring in cloud computing

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Journal of Shanghai University(English Edition) 2011年第5期15卷 381-385页

作者：韩芳芳彭俊杰张武李青李建敦江钦龙袁勤 School of Computer Engineering and Science Shanghai University Key Laboratory of Computer System and Architecture Institute of Computing TechnologyChinese Academy of Science

Cloud computing is a new computing model. The resource monitoring tools are immature compared to traditional distributed computing and grid computing. In order to better monitor the virtual resource in cloud computing, a periodically and event-driven push （PEP） monitoring model is proposed. Taking advantage of the push and event-driven mechanism, the model can provide comparatively adequate information about usage and status of the resources. It can simplify the communication between Master and Work Nodes without missing the important issues happened during the push interval. Besides, we develop ＂mon＂ to make up for the deficiency of Libvirt in monitoring of virtual CPU and memory.

关键词： virtual resource monitoring cloud computing virtualization

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Snooping and ordering ring - An efficient cache coherence protocol for ring connected CMP

Snooping and ordering ring - An efficient cache coherence pr...

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15th International Conference on Parallel and Distributed systems, ICPADS '09

作者： Cao, Fei Liu, Zhiyong Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Science Beijing China

ISBN: (纸本)9780769539003

Ring is a promising on-chip interconnection for CMP. It is more scalable than bus and much simpler than packet-switched networks. The ordering property of ring can be used to optimize cache coherence protocol design. Existing ring protocols, such as the snooping ring protocol and the ring-order protocol need a retry and acknowledgement scheme or use the ordering property of the ring respectively to resolve conflict memory requests. A cache coherence protocol named SOR (Snooping and Ordering Ring) is developed for ring connected CMP in this paper. This protocol is based on the snooping ring protocol. But instead of using the acknowledgement and retry scheme, it uses the ordering property of the ring to resolve conflicts, thus can avoid unnecessary retries to improve performance and power efficiency. The L1 snooping results are sent with the requests instead of being delayed, so that many useless snoops can be avoided. Simulation result shows that the average probe slot transports and snoop operations can be reduced by SOR are 47% and 48.9%. The average and maximum performance improvements by SOR are 3.33% and 6%. © 2009 IEEE.

关键词： Packet switching

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