一句话:提出 CAMP 框架,用 12 个性能计数器解析式地将 CXL 引起的减速分解为三个正交分量,实现 10% 绝对误差内 91–97% 的预测准确率。
异构内存将 DRAM 与 CXL 组合使用,性能波动大,但现有指标与实际减速相关性弱。本文提出 CAMP:核心洞察是一次 DRAM 运行(带宽受限负载再加一次 CXL 运行)即可暴露 CXL 延迟转化为额外处理器停顿周期的因果微架构压力点。CAMP 用 12 个性能计数器将减速解析分解为三个正交分量——需求读、缓存/预取与写,并给出软件加权交织的闭式模型,预测不同 DRAM–CXL 比例下的性能。在 NUMA 与三种 CXL 设备上的 265 个负载中,10% 绝对误差内预测准确率达 91–97%;基于该模型的 Best-shot 交织与同置负载放置策略,相较现有分层与同置方案分别提升最多 21% 与 23%。
Heterogeneous memory combining DRAM and CXL exhibits variable performance, yet existing metrics correlate weakly with actual slowdown. We present CAMP, a principled framework for predicting CXL-induced slowdown. Our key insight is that a DRAM run (plus a CXL run for bandwidth-bound workloads) exposes the causal microarchitectural pressure points where CXL latency translates into additional processor stall cycles. CAMP captures these signals using 12 performance counters to analytically decompose slowdown into three orthogonal components: demand reads, cache/prefetching, and stores. CAMP also introduces a closed-form model for software-based weighted interleaving that predicts performance across DRAM--CXL ratios. Across 265 workloads on NUMA and three CXL devices, CAMP achieves 91--97% prediction accuracy within 10% absolute error. We demonstrate that these models enable practical system policies, including ''Best-shot'' interleaving and colocated workload placement, improving performance by up to 21% and 23% over existing tiering and colocation approaches.