Commit 0bd5ab51 authored by Maciej Fijalkowski's avatar Maciej Fijalkowski Committed by Daniel Borkmann
Browse files

ice, xsk: Decorate ICE_XDP_REDIR with likely() 



ice_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
ice_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/20220413153015.453864-4-maciej.fijalkowski@intel.com
parent 2be4a677

drivers/net/ethernet/intel/ice/ice_xsk.c

+11 −10
Original line number Diff line number Diff line
@@ -629,18 +629,19 @@ int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget) 
		xsk_buff_dma_sync_for_cpu(xdp, rx_ring->xsk_pool);



		xdp_res = ice_run_xdp_zc(rx_ring, xdp, xdp_prog, xdp_ring);

		if (xdp_res) {

			if (xdp_res & (ICE_XDP_TX | ICE_XDP_REDIR))

		if (likely(xdp_res & (ICE_XDP_TX | ICE_XDP_REDIR)))

			xdp_xmit |= xdp_res;

			else

		else if (xdp_res == ICE_XDP_CONSUMED)

			xsk_buff_free(xdp);

		else

			goto construct_skb;



		total_rx_bytes += size;

		total_rx_packets++;



		ice_bump_ntc(rx_ring);

		continue;

		}



construct_skb:

		/* XDP_PASS path */

		skb = ice_construct_skb_zc(rx_ring, xdp);