On Mon, 18 May 2020 16:45:27 +0800 Hangbin Liu <liuhangbin@xxxxxxxxx> wrote: > Hi Toke, > > On Fri, Apr 24, 2020 at 04:34:49PM +0200, Toke Høiland-Jørgensen wrote: > > > > Yeah, the new helper is much cleaner! > > > > > To achive this I add a new ex_map for struct bpf_redirect_info. > > > in the helper I set tgt_value to NULL to make a difference with > > > bpf_xdp_redirect_map() > > > > > > We also add a flag *BPF_F_EXCLUDE_INGRESS* incase you don't want to > > > create a exclude map for each interface and just want to exclude the > > > ingress interface. > > > > > > The general data path is kept in net/core/filter.c. The native data > > > path is in kernel/bpf/devmap.c so we can use direct calls to > > > get better performace. > > > > Got any performance numbers? :) > > Recently I tried with pktgen to get the performance number. It works > with native mode, although the number looks not high. > > I tested it on VM with 1 cpu core. Performance testing on a VM doesn't really make much sense. > By forwarding to 7 ports, With pktgen > config like: > echo "count 10000000" > /proc/net/pktgen/veth0 > echo "clone_skb 0" > /proc/net/pktgen/veth0 > echo "pkt_size 64" > /proc/net/pktgen/veth0 > echo "dst 224.1.1.10" > /proc/net/pktgen/veth0 > > I got forwarding number like: > Forwarding 159958 pkt/s > Forwarding 160213 pkt/s > Forwarding 160448 pkt/s > > But when testing generic mode, I got system crashed directly. The code > path is: > do_xdp_generic() > - netif_receive_generic_xdp() > - pskb_expand_head() <- skb_is_nonlinear(skb) > - BUG_ON(skb_shared(skb)) > > So I want to ask do you have the same issue with pktgen? Any workaround? Pktgen is not meant to be used on virtual devices. -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
