On Thu, Nov 26, 2020 at 11:51:19AM +0100, Jesper Dangaard Brouer wrote: > On Thu, 26 Nov 2020 16:43:25 +0800 > Hangbin Liu <liuhangbin@xxxxxxxxx> wrote: > > > Current sample test xdp_redirect_map only count pkts on ingress. But we > > can't know whether the pkts are redirected or dropped. So add a counter > > on egress interface so we could know how many pkts are redirect in fact. > > This is not true. > > The 2nd devmap XDP-prog will run in the same RX-context, so it doesn't > tell us if the redirect was successful. I looked up the code, and the > 2nd XDP-prog is even allowed to run when the egress driver doesn't > support the NDO to xmit (dev->netdev_ops->ndo_xdp_xmit), which is very > misleading, if you place a output counter here. > > -- > Best regards, > Jesper Dangaard Brouer > MSc.CS, Principal Kernel Engineer at Red Hat > LinkedIn: http://www.linkedin.com/in/brouer > > > static inline int __xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, > struct net_device *dev_rx) > { > struct xdp_frame *xdpf; > int err; > > if (!dev->netdev_ops->ndo_xdp_xmit) > return -EOPNOTSUPP; > Err... You are right. I didn't read this part carefully. Based on Toke's suggestion, maybe edit the src mac address to the egress iface's mac address is a better example. WDYT? And does it make any sense to run perf test for 2nd xdp program for xdp_redirect_map? Thanks Hangbin > err = xdp_ok_fwd_dev(dev, xdp->data_end - xdp->data); > if (unlikely(err)) > return err; > > xdpf = xdp_convert_buff_to_frame(xdp); > if (unlikely(!xdpf)) > return -EOVERFLOW; > > bq_enqueue(dev, xdpf, dev_rx); > return 0; > } > > > int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp, > struct net_device *dev_rx) > { > struct net_device *dev = dst->dev; > > if (dst->xdp_prog) { > xdp = dev_map_run_prog(dev, xdp, dst->xdp_prog); > if (!xdp) > return 0; > } > return __xdp_enqueue(dev, xdp, dev_rx); > } >
