Rethinking Tiered Memory Management in Cloud Data Centers

Cloud environments continue to experience substantial memory wastage due to inefficient resource sharing and workload variability. Emerging Compute Express Link (CXL) technology offers fabric-attached memory that can expand memory capacity despite added access latency, but existing VM allocation strategies in the Cloud have critical limitations. The static partitioning of local DRAM and CXL memory underutilize capacity, and cannot adapt to dynamic demands. Conversely, Host-managed tiering (software-managed placement) relies on page-table scans or sampling, which incur high CPU overhead.