CSR: Medium: WasteNot: Streamlining Virtual Memory for Modern Systems

CSR：中：WasteNot：简化现代系统的虚拟内存

• 批准号: 1302260
• 负责人: Michael Swift
• 金额: $ 74.91万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1302260&HistoricalAwards=false
• 关键词: CSR; Medium; WasteNot; Streamlining; Virtual

This proposal attacks waste in virtual memory. Virtual memory was invented in a time of scarcity (e.g., sub-MB memory) but is now deployed to a changed world with vast memory (e.g., GB to TB) where programs often don?t exploit virtual memories generality (e.g., web servers sized to not swap). At the same time, virtual memory can waste substantial execution time (on translation look aside buffer (TLB) misses) and power (accessing TLBs on each memory reference). Moreover, system extensions to support general-purpose graphics processing units (GP-GPUs) and virtual machine (VMM) challenge virtual memory more. The central hypothesis of this proposal is that memory is too virtual: most workloads do not need all of the benefits of virtual memory most of the time. To this end, we seek to de-virtualize virtual memory with multiple translation mechanisms that offer better performance with less functionality so that applications pay (performance, power/energy, space, etc.) for the features they require instead of for page-based virtual memory?s full generality always. This work reduces waste in computer systems to enable continued improvements in thier cost and performance. This improvement facilitates application innovations like higher performance for big-data workloads, including graph analysis, and environmental benefits from reduced power consumption. Beyond technical advices, this work develops and disseminates tools that leverage other NSF investments, such as the open-source ?gem5? computer-system simulation system.

该提案攻击虚拟内存的浪费。虚拟内存是在稀缺时期发明的（例如，亚 MB 内存），但现在被部署到一个拥有大量内存（例如，GB 到 TB）的变化世界，其中程序通常不利用虚拟内存的通用性（例如，Web 服务器）大小不能交换）。同时，虚拟内存可能会浪费大量执行时间（在转换后备缓冲区 (TLB) 未命中时）和功耗（访问每个内存引用上的 TLB）。此外，支持通用图形处理单元（GP-GPU）和虚拟机（VMM）的系统扩展对虚拟内存提出了更大的挑战。该提案的中心假设是内存过于虚拟：大多数工作负载在大多数情况下并不需要虚拟内存的所有优势。为此，我们寻求通过多种转换机制对虚拟内存进行去虚拟化，以更少的功能提供更好的性能，以便应用程序为它们所需的功能而不是基于页面的功能付费（性能、功耗/能源、空间等）。虚拟内存始终具有完全的通用性。这项工作减少了计算机系统的浪费，从而能够持续改进其成本和性能。这一改进促进了应用程序创新，例如大数据工作负载的更高性能（包括图形分析）以及降低功耗带来的环境效益。除了技术建议之外，这项工作还开发和传播了利用其他 NSF 投资的工具，例如开源“gem5”。计算机系统模拟系统。