Fri, Jun 07, 2024 at 05:14:51PM CEST, jgg@xxxxxxxxxx wrote: >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 switch sdk is all about control plane. >write here a commitment to accept patches blocking such usages if >drivers try to abuse the purpose of the subsystem. > >Jason
