A unified practical approach to stochastic DVS scheduling
A unified practical approach to stochastic DVS scheduling
复制标题
随机 DVS 调度的统一实用方法
DOI：
10.1145/1289927.1289939
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
D. Mossé
中科院分区：
文献类型：
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作者：
Ruibin Xu;R. Melhem;D. Mossé
本文讨论了使用动态电压调节 (DVS) 为执行可变和不可预测工作负载的能源受限嵌入式系统进行能源感知实时系统调度。目标是设计 DVS 方案，在满足任务期限的同时最小化整个系统的预期能耗。研究人员试图利用有关工作负载的随机信息来实现更好的节能，因此，提出了各种随机 DVS 方案。然而，现有的随机 DVS 方案基于非常简化的功率模型，该模型假设不受限制的连续频率、明确定义的功率/频率关系以及无速度变化开销。当这些方案在实践中使用时，需要对其进行修补以符合实际的功率模型。实验表明，某些此类 DVS 方案的性能甚至比某些非随机 DVS 方案还要差。此外，即使对于实验证明优于非随机方案的随机方案，也不清楚它们与尚未找到的最佳解决方案相比表现如何。在这项工作中，我们提供了一种统一的实用方法，用于在现实功率模型下获得最佳（或可证明接近最佳）随机任务间、任务内和混合 DVS 方案，其中处理器仅提供一组离散速度，不对功率/频率关系做出假设，并考虑速度变化开销。我们还通过将现有的 DVS 方案与我们的 DVS 方案进行比较来评估它们。
This paper deals with energy-aware real-time system scheduling using dynamic voltage scaling (DVS) for energy-constrained embedded systems that execute variable and unpredictable workloads. The goal is to design DVS schemes to minimize the expected energy consumption of the whole system while meeting the deadlines of the tasks. Researchers have attempted to take advantage of stochastic information about workloads to achieve better energy savings, and accordingly, various stochastic DVS schemes have been proposed. However, the existing stochastic DVS schemes are based on much simplified power models that assume unrestricted continuous frequency, well-defined power/frequency relation, and no speed change overhead. When these schemes are used in practice, they need to be patched in order to comply with realistic power models. Experiments show that some of such DVS schemes perform even worse than certain non-stochastic DVS schemes. Furthermore, even for stochastic schemes that were shown experimentally to outperform non-stochastic schemes, it is not clear how well they perform compared to the optimal solution, which is yet to be found. In this work, we provide a unified practical approach for obtaining optimal (or provably close to optimal) stochastic inter-task, intra-task, and hybrid DVS schemes under realistic power models in which the processor only provides a set of discrete speeds, no assumption is made on power/frequency relation, and speed change overhead is considered. We also evaluate the existing DVS schemes by comparing them with our DVS schemes.