Fat Caches for Scale-Out Servers
Fat Caches for Scale-Out Servers
复制标题
横向扩展服务器的胖缓存
作者：
Stavros Volos;Djordje Jevdjic;B. Falsafi;Boris Grot
新兴的横向扩展服务器的特点是大量的内存占用和带宽需求。已经提出了片上堆叠DRAM高速缓存，以通过对辅助数据工作集的高速缓存来为众核服务器提供所需的带宽。然而，所提供的容量和工作集大小之间的差距排除了它们在服务器中的有效部署，需要高容量的缓存架构。高容量缓存-启用的高带宽内存技术的出现-表现出高时空局部性，由于粗粒度的访问模式和长缓存驻留期源于偏斜的数据集访问分布。观察到的时空行为有利于基于页面的组织，自然利用空间的局部性，同时最大限度地减少标签存储的要求，并使一个实用的在SRAM标签阵列架构。通过将标签存储在SRAM中，高速缓存避免了在最先进的DRAM高速缓存中发现的DRAM内元数据的复杂性。
Emerging scale-out servers are characterized by massive memory footprints and bandwidth requirements. On-chip stacked DRAM caches have been proposed to provide the required bandwidth for manycore servers through caching of secondary data working sets. However, the disparity between provided capacity and working set sizes precludes their effective deployment in servers, calling for high-capacity cache architectures. High-capacity caches--enabled by the emergence of high-bandwidth memory technologies--exhibit high spatiotemporal locality due to coarse-grained access patterns and long cache residency periods stemming from skewed dataset access distributions. The observed spatiotemporal behavior favors a page-based organization that naturally exploits spatial locality while minimizing tag storage requirements and enabling a practical in-SRAM tag array architecture. By storing tags in SRAM, caches avoid the complexity of in-DRAM metadata found in state-of-the-art DRAM caches.