tree 77e091a3b5de3c55433947ec41891ba2b1e52019
parent d2cee2e5d0106abb5da25f393b3c50e0bb01f7f9
author Jesper Dangaard Brouer <brouer@redhat.com> 1502986957 +0200
committer David S. Miller <davem@davemloft.net> 1503098320 -0700

xdp: adjust xdp redirect tracepoint to include return error code

The return error code need to be included in the tracepoint
xdp:xdp_redirect, else its not possible to distinguish successful or
failed XDP_REDIRECT transmits.

XDP have no queuing mechanism. Thus, it is fairly easily to overrun a
NIC transmit queue.  The eBPF program invoking helpers (bpf_redirect
or bpf_redirect_map) to redirect a packet doesn't get any feedback
whether the packet was actually transmitted.

Info on failed transmits in the tracepoint xdp:xdp_redirect, is
interesting as this opens for providing a feedback-loop to the
receiving XDP program.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>