Cowbird: Freeing CPUs to Compute by Offloading the Disaggregation of Memory

Memory disaggregation allows applications running on compute servers to expand their pool of available memory capacity by leveraging remote resources through low-latency networks. Unfortunately, in existing software-level disaggregation frameworks, the simple act of issuing requests to remote memory-paid on every access-can consume many CPU cycles. This overhead represents a direct cost to disaggregation, not only on the throughput of remote memory access but also on application logic, which must contend with the framework's CPU overheads. In this paper, we present Cowbird, a memory disaggregation architecture that frees compute servers to fulfill their stated purpose by removing disaggregation-related logic from their CPUs. Our experimental evaluation shows that Cowbird eliminates disaggregation overhead on compute-server CPUs and can improve end-to-end application performance by up to 3.5x compared to RDMA-only communication.