关键词： 分布式处理体系   高速串行总线   多处理器   通信协议   RapidIO   TIPC   通信软件设计  

摘要： 将透明处理器间通信协议(TIPC)与基于高性能包交换的RapidIO总线相结合,并对RapidIO的应用层协议进行扩展和定义,可以实现全新的基于RapidIO网络的TIPC通信软件。该软件采用层次化和可扩展的协议来定义开放处理器间的通信协议,为各种应用提供面向消息的、与位置无关的通信服务和标准的API函数接口,为解决多处理器、多模块和多系统互连问题提供了方案。基于Ra-pidIO网络的TIPC通信软件在测试中取得了良好的测试结果。

关键词： 多处理器   实时系统   最早截止期优先   负载计算   干涉   松弛  

摘要： 在多处理器实时调度过程中,干涉上界的取值对于可调度性判定的性能具有较大影响。为此,针对实时系统的最早截止期优先调度算法,引入任务松弛的有关概念,提出一种基于负载计算的可调度性判定方法。通过减小问题区间内带入作业的工作负载取值,增加任务集通过可调度性判定的可能。实验结果表明,随着处理器数量的增加,该判定方法较传统方法有5%~10%的性能提升。

关键词： 异构多处理器   嵌入式计算平台   RFID读写机具   Cortex   M3   MSP430  

摘要： 提出了采用异构多处理器体系结构构建嵌入式计算平台的思想,并基于该思想采用Cortex M3主处理器和MSP430协处理器构建了异构多处理器体系结构的433 MHz有源RFID读写机具。实际验证结果表明,采用异构多处理器构建的嵌入式计算平台实现了计算密集型应用与控制密集型应用的有效分离,大大提高了系统的灵活性和资源分配的合理性。基于该体系结构重构传统嵌入式计算平台时对应用系统透明,使其具有广泛的应用前景。

关键词： 单芯片多处理器   热阻矩阵   三维集成   温度  

摘要： 给出热阻矩阵的表达式,研究三维单芯片多处理器(3D CMP,three-dimensional chip-multiprocessor)的温度特性,通过Matlab分析热容、热阻和功耗对温度的影响.结果表明:减小热阻和功耗可以有效约束3D CMP的稳态温度;热容增大可以导致3D CMP温度上升时间变长,但不影响其最终稳态温度.

关键词： 多处理器   消息机制   FPGA   DMA  

摘要： 描述了一种基于消息机制构建的片上多处理器系统。该系统采用主从结构,运用消息进行通信,并且从处理器之间彼此相互独立,在硬件结构与软件设计上保持一致。这样不仅简化了系统的设计,更使得系统具有一定的容错性与稳定性。最后在Quartus软件中设计并且综合,在该系统下运行JPEG编码算法,当运行于100MHz时,测得系统在不同个数处理器时的处理性能,满足了设计要求。

关键词： dynamic grouping   fault-tolerant   overloading   primary backup   backup backup  

摘要： In order to extend the application area of fault-tolerant scheduling algorithm based on hybrid overloading for multiprocessor and increase the fault-tolerant number of processors, we propose a new fault-tolerant scheduling algorithm, which is based on hybrid overloading and dynamic grouping for multiprocessor by combining logic grouping strategy for processors in primary backup overloading and backup backup *** algorithm presents the formalization of the dynamic grouping for processors in fault-tolerant scheduling based on hybrid overloading and enlarges the task number included in overloading task link. In the process of fault-tolerant scheduling the processors are dynamically divided into some groups based on overloading task link, so as to keep good scheduling success ratio and enhance the fault-tolerant performance of processors. Both theoretical analysis and simulation experiment prove this algorithm's effectiveness respectively.

关键词： Energy consumption   list scheduling   performance analysis   power-aware scheduling   precedence constraint   simulation   task scheduling  

摘要： Energy-efficient scheduling of sequential tasks with precedence constraints on multiprocessor computers with dynamically variable voltage and speed is investigated as combinatorial optimization problems. In particular, the problem of minimizing schedule length with energy consumption constraint and the problem of minimizing energy consumption with schedule length constraint are considered. Our scheduling problems contain three nontrivial subproblems, namely, precedence constraining, task scheduling, and power supplying. Each subproblem should be solved efficiently so that heuristic algorithms with overall good performance can be developed. Such decomposition of our optimization problems into three subproblems makes design and analysis of heuristic algorithms tractable. Three types of heuristic power allocation and scheduling algorithms are proposed for precedence constrained sequential tasks with energy and time constraints, namely, prepower-determination algorithms, postpower-determination algorithms, and hybrid algorithms. The performance of our algorithms are analyzed and compared with optimal schedules analytically. Such analysis has not been conducted in the literature for any algorithm. Therefore, our investigation in this paper makes initial contribution to analytical performance study of heuristic power allocation and scheduling algorithms for precedence constrained sequential tasks. Our extensive simulation data demonstrate that for wide task graphs, the performance ratios of all our heuristic algorithms approach one as the number of tasks increases.

关键词： 多处理器调度算法   线性时序逻辑   模型检测   扩展Büchi自动机  

摘要： 在多处理器系统中,一个应用所要完成的任务可以分配给同一个处理器处理,也可以分配给多个处理器处理,所以传统的测试方法难以满足多处理器任务调度算法的验证。在此,提出一个基于扩展Büchi自动机的形式化模型,并用该模型来描述多处理器任务调度算法TDS(Task Duplication based Scheduling);用线性时序逻辑描述出算法TDS期望的一些性质;最后在该模型上验证了这些性质。该方法有效地克服了传统测试的局限性,保证了多处理器任务调度的可靠性。

关键词： Circuit switching   network-on-chip   communication   data access pattern   data partition  

摘要： Data access latency, a limiting factor in the performance of chip multiprocessors, grows significantly with the number of cores in nonuniform cache architectures with distributed cache banks. To mitigate this effect, we use a compiler-based approach to leverage data access locality, choose an optimized data placement and efficiently configure the on-chip network. The proposed experimental compiler framework employs novel compilation techniques to discover and represent multithreaded memory access patterns (MMAPs). At runtime, symbolic MMAPs are resolved and used by a partitioning algorithm to choose a partition of allocated memory blocks among the forked threads in the analyzed application. This partition is used to enforce data ownership by associating the data with the core that executes the thread owning the data. Based on the partition, the communication pattern of the application can be extracted. We demonstrate how this information can be used in an experimental architecture to accelerate applications. In particular, our compiler assisted data partitioning approach shows a 20 percent speedup over shared caching and 5 percent speedup over the closest runtime approximation, first touch. By leveraging the communication pattern we can achieve a comparable performance to a system that uses a complex centralized network configuration system at runtime. Thus, our final system saves significant runtime complexity and achieves an 5.1 percent additional speedup through the addition of the reconfigurable network.

关键词： 混合实时系统   多处理器系统   BFair调度算法   boundary—fair  

摘要： 比例公平调度PFair(Proportionate-Fair)算法和边界公平调度BFair(Boundary-fair)是多处理器系统上周期性实时任务的最佳全局调度方法,但在实际的实时系统中,实时任务往往是周期任务和非周期任务混合的任务系统,在研究PFair和BFair调度算法的基础上,提出了基于服务器思想的公平调度方案,实现了对混合实时任务的调度,同时保证了任务公平地使用共享资源,使得公平调度算法适用于多处理器系统中的混合实时任务调度,扩展了其适用范围。