CSR: Small: Software Cache Memory Managements with Reconfigurable Hardware Emulators

随着多核系统成为主要的计算平台，高效的缓存管理对系统性能和能效的影响比以往更加重要。一种有效的方法是使用硬件支持的软件缓存管理(SCM)来管理共享的末级缓存，因为复杂的软件缓存管理可以适应多核处理器上缓存使用的复杂场景，而软件缓存管理中的一个关键和悬而未决的问题是缺乏丰富的相关信息来分析不同配置下的缓存性能。该项目研究使用轻量级和可重新配置的硬件缓存仿真器(RCE)来扩展SCM的功能。有了这种新的硬件支持，就可以开发复杂的SCM算法，通过RCE持续监控缓存使用情况。这些SCM算法旨在通过关闭未使用的缓存部分来提高缓存能效，优化多核处理器的缓存分区，并改进软件控制的缓存映射以提高缓存利用率。研究将提高笔记本电脑、台式机和服务器电脑使用大型共享缓存的多核处理器的系统性能、电源效率和性能可预测性。它可能会对工业处理器设计产生影响，包括轻量级RCE以及丰富的SCM算法。它还将为学生介绍新的教材，通过动手实验学习多核缓存管理。

As multi-core systems become the major computing platform, efficient cache management is even more crucial to system performance and power efficiency than before. An effective approach is to use software cache management (SCM) with hardware supports to manage shared last-level cache, because sophisticated SCM may adapt to the complex scenarios of cache usage on multi-core processors.A critical and unsolved issue in SCM is the lack of rich and relevant information for software to reason about cache performance under different configurations. The project investigates the use of lightweight and Reconfigurable hardware Cache Emulators (RCEs) to extend the capability of SCM. With this new hardware support, sophisticated SCM algorithms that constantly monitor cache usage through RCEs are developed. Those SCM algorithms aim to improve cache power efficiency by turning off unused cache portion, optimize cache partitioning for multi-core processors, and improve software-controlled cache mapping to improve cache utilization.The research will improve system performance, power efficiency, and performance predictability for laptop, desktop and server computers using multi-core processors of large shared caches. It may make an impact on industry processor design to include lightweight RCEs as well as enrich SCM algorithms. It will also introduce new educational materials for students to study multicore cache management through hand-on experiments.