On 05/04/2022 13.06, Maciej Fijalkowski wrote:
Correlate -ENOBUFS that was returned from xdp_do_redirect() with a XSK
Rx queue being full. In such case, terminate the softirq processing and
let the user space to consume descriptors from XSK Rx queue so that
there is room that driver can use later on.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
---
.../ethernet/intel/i40e/i40e_txrx_common.h | 1 +
drivers/net/ethernet/intel/i40e/i40e_xsk.c | 21 ++++++++++++-------
2 files changed, 15 insertions(+), 7 deletions(-)
[...]
I noticed you are only doing this for the Zero-Copy variants.
Wouldn't this also be a benefit for normal AF_XDP ?
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index c1d25b0b0ca2..9f9e4ce9a24d 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -161,9 +161,10 @@ static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
if (likely(act == XDP_REDIRECT)) {
err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
- if (err)
- goto out_failure;
- return I40E_XDP_REDIR;
+ if (!err)
+ return I40E_XDP_REDIR;
+ result = (err == -ENOBUFS) ? I40E_XDP_EXIT : I40E_XDP_CONSUMED;
+ goto out_failure;
}
switch (act) {
@@ -175,6 +176,9 @@ static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
if (result == I40E_XDP_CONSUMED)
goto out_failure;
break;
+ case XDP_DROP:
+ result = I40E_XDP_CONSUMED;
+ break;
default:
bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
fallthrough;
@@ -182,9 +186,6 @@ static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
out_failure:
trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
fallthrough; /* handle aborts by dropping packet */
- case XDP_DROP:
- result = I40E_XDP_CONSUMED;
- break;
}
return result;
}
@@ -370,6 +371,12 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
xsk_buff_dma_sync_for_cpu(bi, rx_ring->xsk_pool);
xdp_res = i40e_run_xdp_zc(rx_ring, bi);
+ if (xdp_res == I40E_XDP_EXIT) {
+ failure = true;
+ xsk_buff_free(bi);
+ next_to_clean = (next_to_clean + 1) & count_mask;
+ break;
+ }
i40e_handle_xdp_result_zc(rx_ring, bi, rx_desc, &rx_packets,
&rx_bytes, size, xdp_res);
total_rx_packets += rx_packets;
@@ -382,7 +389,7 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
cleaned_count = (next_to_clean - rx_ring->next_to_use - 1) & count_mask;
if (cleaned_count >= I40E_RX_BUFFER_WRITE)
- failure = !i40e_alloc_rx_buffers_zc(rx_ring, cleaned_count);
+ failure |= !i40e_alloc_rx_buffers_zc(rx_ring, cleaned_count);
i40e_finalize_xdp_rx(rx_ring, xdp_xmit);
i40e_update_rx_stats(rx_ring, total_rx_bytes, total_rx_packets);
