Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote: > > It might make more sense to intentionally have packets > > flow through the normal path periodically so neigh entries are up to > > date. > > Hmm, I see what you mean, but I worry that this would lead to some nasty > latency blips when a flow transitions back and forth between kernel and > XDP paths. Also, there's a reordering problem as the state is changed: > the first goes through the stack, sets the flow state to active, then > gets transmitted. But while that sits in the qdisc waiting to go out on > the wire, the next packet arrives, gets handled by the XDP fastpath and > ends up overtaking the first packet on the TX side. Not sure we have a > good solution for this in general :( >From nft based flowtable offload we already had a feature request to bounce flows back to normal path periodially, this was because people wanted to make sure that long-living flows get revalidated vs. current netfilter ruleset and not the one that was active at flow offload time. There was a patch for it, using a new sysctl, and author never came back with an updated patch to handle this via the ruleset instead.
