On Fri, Jun 07, 2024 at 08:50:17AM -0600, David Ahern wrote: > Mellanox offers both with the Spectrum line and should have a pretty > good understanding of how many customers deploy with the SDK vs > switchdev. Why is that? We offer lots of options with mlx5 switching too, and switchdev is not being selected by customers principally for performance reasons, in my view. The OVS space wants to operate the switch much like a firewall and this creates a high rate of database updates and exception packets. DPDK can operate all the same offload HW from userspace and avoid all the system call and other kernel overhead. It is much more purpose built to what OVS wants to do. In the >50Gbps space this matters a lot and overall DPDK performance notably wins over switchdev for many OVS workloads - even though the high speed path is near-identical. In this role DPDK is effectively a switch SDK, an open source one at least. Sadly I'm seeing signs that proprietary OVS focused SDKs (think various P4 offerings and others) are out competing open DPDK on merit :( For whatever reason the market for switching is not strongly motivated toward open SDKs, and the available open solutions are struggling a bit to compete. But to repeat again, fwctl is not for dataplane, it is not for implementing a switch SDK (go use RDMA if you want to do that). I will write here a commitment to accept patches blocking such usages if drivers try to abuse the purpose of the subsystem. Jason
