MBBA: A Multi-Bandwidth Bus Arbiter for Hard Real-Time
MBBA: A Multi-Bandwidth Bus Arbiter for Hard Real-Time
复制标题
MBBA：用于硬实时的多带宽总线仲裁器
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
P. Sainrat
中科院分区：
文献类型：
--
作者：
Roman Bourgade;Christine Rochange;M. De Michiel;P. Sainrat
多核架构在嵌入式系统中的应用越来越多，因为它们提供了几个优点：改进的硬件集成度，低散热和降低能耗，同时它们可以提高计算能力。为了在多核架构上运行实时软件，计算每个线程的最坏情况执行时间应该是可以实现的。这特别涉及通过采用可预测的总线仲裁器来绑定存储器延迟。然而，国家的最先进的技术被证明是无关的调度不平衡的工作负载，其中一些线程需要更多的总线带宽比其他的。本文提出了一种新的总线仲裁方案，该方案保证了共享总线延迟的上界性。相比其他计划，使总线延迟可预测的，如轮循协议，我们的方法定义了几个级别的带宽，以满足要求，可能会有所不同，从一个线程到另一个。实验结果（WCET估计）表明，最坏情况下的总线延迟显着缩短，相比轮询，具有最高优先级的核心，获得最大的带宽。该计划的相关性是通过一个例子组成的各种基准的工作量。
Multi-core architectures are being increasingly used in embedded systems as they offer several advantages: improved hardware integration, low thermal dissipation and reduced energy consumption, while they make it possible to improve the computing power. In order to run real-time software on a multicore architecture, computing the Worst-Case Execution Time of every thread should be achievable. This notably involves bounding memory latencies by employing a predictable bus arbiter. However, state-of-the-art techniques prove to be irrelevant to schedule unbalanced workloads in which some threads require more bus bandwidth than the other ones. This paper proposes a new bus arbitration scheme that ensures that the shared bus latencies can be upper bounded. Compared to other schemes that make the bus latencies predictable, like the Round-Robin protocol, our approach defines several levels of bandwidth to meet requirements that may vary from one thread to another. Experimental results (WCET estimates) show that the worst-case bus latency is noticeably shortened, compared to Round-Robin, for the cores with highest priority that get the largest bandwidth. The relevance of the scheme is shown through an example workload composed of various benchmarks.