On 11/11/2019 10:51, Arthur Fabre wrote:
> The sfc driver can drop packets processed with XDP, notably when running
> out of buffer space on XDP_TX, or returning an unknown XDP action.
> This increments the rx_xdp_bad_drops ethtool counter.
>
> Call trace_xdp_exception everywhere rx_xdp_bad_drops is incremented to
> easily monitor this from userspace.
>
> This mirrors the behavior of other drivers.
>
> Signed-off-by: Arthur Fabre <afabre@xxxxxxxxxxxxxx>
> ---
> drivers/net/ethernet/sfc/rx.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
> index a7d9841105d8..5bfe1f6112a1 100644
> --- a/drivers/net/ethernet/sfc/rx.c
> +++ b/drivers/net/ethernet/sfc/rx.c
> @@ -678,6 +678,7 @@ static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel,
> "XDP is not possible with multiple receive fragments (%d)\n",
> channel->rx_pkt_n_frags);
> channel->n_rx_xdp_bad_drops++;
> + trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
> return false;
> }
AIUI trace_xdp_exception() is improper here as we have not run
the XDP program (and xdp_act is thus uninitialised).
The other three, below, appear to be correct.
-Ed
>
> @@ -724,6 +725,7 @@ static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel,
> netif_err(efx, rx_err, efx->net_dev,
> "XDP TX failed (%d)\n", err);
> channel->n_rx_xdp_bad_drops++;
> + trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
> } else {
> channel->n_rx_xdp_tx++;
> }
> @@ -737,6 +739,7 @@ static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel,
> netif_err(efx, rx_err, efx->net_dev,
> "XDP redirect failed (%d)\n", err);
> channel->n_rx_xdp_bad_drops++;
> + trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
> } else {
> channel->n_rx_xdp_redirect++;
> }
> @@ -746,6 +749,7 @@ static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel,
> bpf_warn_invalid_xdp_action(xdp_act);
> efx_free_rx_buffers(rx_queue, rx_buf, 1);
> channel->n_rx_xdp_bad_drops++;
> + trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
> break;
>
> case XDP_ABORTED:
