Intel Continues Bringing Up DMA-BUF Support For RDMA
Intel engineers are working to support DMA-BUF for peer-to-peer transactions over PCI Express between RDMA NICs and supported PCIe devices/drivers.
The peer-to-peer support with capable hardware and drivers means bypassing the system memory when the CPU doesn't need to access it, in turn offering better performance. AMD engineers have also been investing in Linux's peer-to-peer DMA capabilities as well.
Intel selected the DMA-BUF interface for the RDMA P2P focus due to already being supported by GPU drivers and they feeling it is better tailored for this purpose than the likes of Heterogeneous Memory Management, PCI P2P DMA, and alternatives.
Intel's Linux graphics driver would still need changes for making use of this P2P RDMA support but presumably it will be coming as part of Xe HP/HPC enablement. The latest RDMA DMA-BUF patches were sent out on Sunday.