From: Alexei Starovoitov <a...@plumgrid.com> Date: Thu, 4 Jun 2015 10:11:53 -0700
> eBPF programs attached to ingress and egress qdiscs see inconsistent > skb->data. > For ingress L2 header is already pulled, whereas for egress it's present. > This is known to program writers which are currently forced to use > BPF_LL_OFF workaround. > Since programs don't change skb internal pointers it is safe to do > pull/push right around invocation of the program and earlier taps and > later pt->func() will not be affected. > Multiple taps via packet_rcv(), tpacket_rcv() are doing the same trick > around run_filter/BPF_PROG_RUN even if skb_shared. > > This fix finally allows programs to use optimized LD_ABS/IND instructions > without BPF_LL_OFF for higher performance. > tc ingress + cls_bpf + samples/bpf/tcbpf1_kern.o > w/o JIT w/JIT > before 20.5 23.6 Mpps > after 21.8 26.6 Mpps > > Old programs with BPF_LL_OFF will still work as-is. > > We can now undo most of the earlier workaround commit: > a166151cbe33 ("bpf: fix bpf helpers to use skb->mac_header relative offsets") > > Signed-off-by: Alexei Starovoitov <a...@plumgrid.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html