Show HN: Nvshmem from Scratch – RDMA, GPUDirect, and GPU Networking Demystified

I wrote a guide that walks through building a minimal GPU-initiated networking library from the ground up. It covers RDMA transport with libfabric on AWS EFA, PCIe topology-aware GPU-NIC placement, GPUDirect RDMA via DMA-BUF, CUDA IPC for intra-node NVLink transfers, and the symmetric memory model that ties it all together. Each section includes working code and benchmarks.