On 12/9/20 4:52 AM, Jesper Dangaard Brouer wrote: >>> still load and either share queues across multiple cores or restirct >>> down to a subset of CPUs. >> >> And that's the missing piece of logic, I suppose. >> >>> Do you need 192 cores for a 10gbps nic, probably not. >> >> Let's hear from Jesper :p > > LOL - of-cause you don't need 192 cores. With XDP I will claim that > you only need 2 cores (with high GHz) to forward 10gbps wirespeed small > packets. You don't need 192 for 10G on Rx. However, if you are using XDP_REDIRECT from VM tap devices the next device (presumably the host NIC) does need to be able to handle the redirect. My personal experience with this one is mlx5/ConnectX4-LX with a limit of 63 queues and a server with 96 logical cpus. If the vhost thread for the tap device runs on a cpu that does not have an XDP TX Queue, the packet is dropped. This is a really bizarre case to debug as some packets go out fine while others are dropped.
