Real-time analysis of priority-preemptive NoCs with arbitrary buffer sizes and router delays
Real-time analysis of priority-preemptive NoCs with arbitrary buffer sizes and router delays
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DOI：
10.1007/s11241-018-9312-0
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发表时间：
2018-06
影响因子：
1.3
通讯作者：
Borislav Nikolic;Sebastian Tobuschat;L. Indrusiak;R. Ernst;A. Burns
中科院分区：
文献类型：
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作者：
Borislav Nikolic;Sebastian Tobuschat;L. Indrusiak;R. Ernst;A. Burns
由于片上网络（NoC）具有良好的可扩展性和性能，目前多处理器平台主要使用NoC架构作为互连介质。在过去的十年中，NoC受到了实时社区的大量关注。一个有前途的类别的方法建议采用已经存在的硬件功能，称为虚拟通道，并专用于他们，专门为个人的通信业务流。通过这种方式，NoC变得更适合实时分析，这是提供安全和严格的最坏情况分析方法的基本要求，并因此获得实时保证。在这篇手稿中，我们提出的方法，其中福尔斯属于上述类别。具体来说，我们提出了一种新的方法，最坏情况下的NoC流量分析，假设存在的每流专用虚拟通道。与最先进的技术相比，我们的方法产生了更严格的上限上的最坏情况下的遍历时间（WCTTs）的通信流量。通过采用所提出的方法，可以在很大程度上减轻资源过度配置，并可以实现显着的设计成本降低。此外，我们实现了一个周期准确的模拟器的假设的NoC架构，并使用它来评估派生的WCTT界限的紧密性。最后，我们得出了一个有趣的结论，即更大的虚拟通道缓冲区不一定会带来更好的结果，在许多情况下可能会适得其反，这对系统设计人员来说是一个非常重要的发现。
Nowadays available multiprocessor platforms predominantly use a network-on-chip (NoC) architecture as an interconnect medium, due to its good scalability and performance. During the last decade, NoCs received a significant amount of attention from the real-time community. One promising category of approaches suggests to employ already existing hardware features called virtual channels, and dedicate them, exclusively, to individual communication traffic flows. In this way, NoCs become more amenable to the real-time analysis, which is an essential requirement for providing both safe and tight worst-case analysis methods, and consequently deriving real-time guarantees. In this manuscript, we present the approach which falls in the aforementioned category. Specifically, we propose a novel method for the worst-case analysis of the NoC traffic, assuming the existence of per-flow dedicated virtual channels. Compared to the state-of-the-art techniques, our approach yields substantially tighter upper-bounds on the worst-case traversal times (WCTTs) of communication traffic flows. By employing the proposed method, resource over-provisioning can be mitigated to a large extent, and significant design-cost reductions can be achieved. Moreover, we implemented a cycle-accurate simulator of the assumed NoC architecture, and used it to assess the tightness of derived WCTT bounds. Finally, we reached an interesting conclusion that bigger virtual channel buffers do not necessarily lead to better results, and in many cases can be counter-productive, which is a very important finding for system designers.