Commit d090c885 authored by Maciej Fijalkowski's avatar Maciej Fijalkowski Committed by Daniel Borkmann
Browse files

ixgbe, xsk: Decorate IXGBE_XDP_REDIR with likely() 



ixgbe_run_xdp_zc() suggests to compiler that XDP_REDIRECT is the most
probable action returned from BPF program that AF_XDP has in its
pipeline. Let's also bring this suggestion up to the callsite of
ixgbe_run_xdp_zc() so that compiler will be able to generate more
optimized code which in turn will make branch predictor happy.

Suggested-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: default avatarMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220413153015.453864-5-maciej.fijalkowski@intel.com
parent 0bd5ab51

drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c

+13 −12
Original line number Diff line number Diff line
@@ -303,11 +303,12 @@ int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector, 
		xsk_buff_dma_sync_for_cpu(bi->xdp, rx_ring->xsk_pool);

		xdp_res = ixgbe_run_xdp_zc(adapter, rx_ring, bi->xdp);



		if (xdp_res) {

			if (xdp_res & (IXGBE_XDP_TX | IXGBE_XDP_REDIR))

		if (likely(xdp_res & (IXGBE_XDP_TX | IXGBE_XDP_REDIR)))

			xdp_xmit |= xdp_res;

			else

		else if (xdp_res == IXGBE_XDP_CONSUMED)

			xsk_buff_free(bi->xdp);

		else

			goto construct_skb;



		bi->xdp = NULL;

		total_rx_packets++;
@@ -316,8 +317,8 @@ int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector, 
		cleaned_count++;

		ixgbe_inc_ntc(rx_ring);

		continue;

		}



construct_skb:

		/* XDP_PASS path */

		skb = ixgbe_construct_skb_zc(rx_ring, bi->xdp);

		if (!skb) {