BC-AMAT: Considering Blocked Time in Memory System Measurement
BC-AMAT: Considering Blocked Time in Memory System Measurement
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DOI：
10.1145/3075564.3076264
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发表时间：
2017-05
期刊：
影响因子：
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通讯作者：
Qi Yu;Libo Huang;Cheng Qian;Zhiying Wang
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文献类型：
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作者：
Qi Yu;Libo Huang;Cheng Qian;Zhiying Wang
“内存墙”问题不仅要求使用越来越积极的技术来减少内存系统的延迟，而且还要求提出更准确的内存度量。C-AMAT是AMAT的扩展，它同时考虑了存储器访问的局部性和并发性，能够更准确地评估现代存储系统的性能。然而，C-AMAT只涉及那些被存储器访问所消耗的周期，忽略了由硬件预取等技术引起的阻塞时间，这可能导致不准确的评估。在本文中，我们提出了一个更全面的内存度量称为阻塞C-AMAT（BC-AMAT）。它扩展了C-AMAT，考虑了阻塞周期。实验结果表明，BC-AMAT与IPC的相关性比C-AMAT好得多，当几个预取策略被应用在单核模式和多核模式。最后给出了一个应用BC-AMAT算法动态调整预取度的实例。仿真结果表明，BC-AMAT算法比C-AMAT算法具有更好的性能改善效果，证明了BC-AMAT算法在系统优化中的有效性。与C-AMAT相比，BC-AMAT在评估现代存储系统方面更加准确和全面，同时也为体系结构设计提供了更多的见解。
The "memory wall" problem requires not only the use of increasingly aggressive techniques designed to reduce the latency of memory system, but also the raise of more accurate memory metrics. C-AMAT, an extension of AMAT that considers both locality and concurrency of memory accesses, can evaluate the performance of modern memory system more accurately. However, C-AMAT only involves those cycles consumed by memory accesses, ignoring the blocked time caused by some techniques like hardware prefetch, which may result in inaccurate evaluation. In this paper, we propose a more comprehensive memory metric called Blocked C-AMAT (BC-AMAT). It extends C-AMAT to take the blocked cycles into consideration. Experimental results show that BC-AMAT correlates much better with IPC than C-AMAT does when a few prefetch strategies are applied both in single-core mode and multi-core mode. In addition, a case study is provided in which BC-AMAT is used to adjust prefetching degree dynamically. The result shows that BC-AMAT achieves higher performance improvement than C-AMAT, demonstrating its usefulness in system optimization. BC-AMAT is more accurate and comprehensive than C-AMAT in evaluating modern memory systems, meanwhile, provides more insight for architecture design.