Each call to the AVX2 vector burst receive function makes at least one pass through the function's inner loop, loading 256 bytes of completion descriptors and copying 8 rte_mbuf pointers regardless of whether there are any packets to be received.
Unidirectional forwarding performance is improved by about
3-4% if we ensure that at least one packet can be received
before entering the inner loop.
Fixes: c4e4c18963b0 ("net/bnxt: add AVX2 RX/Tx")
Cc: [email protected]
Signed-off-by: Lance Richardson <[email protected]>
---
drivers/net/bnxt/bnxt_rxtx_vec_avx2.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/net/bnxt/bnxt_rxtx_vec_avx2.c
b/drivers/net/bnxt/bnxt_rxtx_vec_avx2.c
index e4905b4fd1..54e3af22ac 100644
--- a/drivers/net/bnxt/bnxt_rxtx_vec_avx2.c
+++ b/drivers/net/bnxt/bnxt_rxtx_vec_avx2.c
@@ -98,6 +98,10 @@ recv_burst_vec_avx2(void *rx_queue, struct rte_mbuf
**rx_pkts, uint16_t nb_pkts)
rte_prefetch0(&cp_desc_ring[cons + 8]);
rte_prefetch0(&cp_desc_ring[cons + 12]);
+ /* Return immediately if there is not at least one completed packet. */
+ if (!bnxt_cpr_cmp_valid(&cp_desc_ring[cons], raw_cons, cp_ring_size))
+ return 0;
+
/* Ensure that we do not go past the ends of the rings. */
nb_pkts = RTE_MIN(nb_pkts, RTE_MIN(rx_ring_size - mbcons,
(cp_ring_size - cons) / 2));
--
2.25.1
smime.p7s
Description: S/MIME Cryptographic Signature
