The high demand for memory capacity in modern datacenters has led to multiple lines of innovation in memory expansion and disaggregation. One such effort is Compute eXpress Link (CXL)-based memory expansion, which has gained significant attention. To better leverage CXL memory, researchers have built several emulation and experimental platforms to study its behavior and characteristics. However, due to the lack of commercial hardware supporting CXL memory, the full picture of its capabilities may still be unclear to the community. In this work, we explore CXL memory's performance characterization on a state-of-the-art experimental platform. First, we study the basic performance characteristics of CXL memory using our proposed microbenchmark. Based on our observations and comparisons to standard DRAM connected to local and remote NUMA nodes, we also study the impact of CXL memory on end-to-end applications with different offloading and interleaving policies. Finally, we provide several guidelines for future programmers to realized the full potential of CXL memory

翻译：现代数据中心对内存容量的高需求催生了多条内存扩展与解耦技术创新路线。其中，基于Compute eXpress Link (CXL)的内存扩展技术备受关注。为更好利用CXL内存，研究者已构建多个仿真与实验平台以分析其行为特性。然而，由于缺乏支持CXL内存的商业硬件，学界对其完整性能画像仍存在认知模糊。本研究在先进实验平台上对CXL内存进行性能表征：首先通过自主设计的微基准测试探究CXL内存基础性能特征；在对比本地及远程NUMA节点连接的DRAM性能后，进一步分析不同卸载策略与交错策略下CXL内核对端到端应用的影响；最终为开发者充分发挥CXL内存潜力提供若干指导准则。