[dpdk-dev] [PATCH v2 6/7] net/qede: prefetch next packet to free

[Balazs Nemeth]

While handling the current mbuf, pull the next mbuf into the cache. Note
that the last four mbufs pulled into the cache are not handled, but that
doesn't matter.

Signed-off-by: Balazs Nemeth <bnemeth at redhat.com>
Reviewed-by: Igor Russkikh <irusskikh at marvell.com>
---
 drivers/net/qede/qede_rxtx.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/qede/qede_rxtx.c b/drivers/net/qede/qede_rxtx.c
index 4f58abfbf..ed3617160 100644
--- a/drivers/net/qede/qede_rxtx.c
+++ b/drivers/net/qede/qede_rxtx.c
@@ -917,6 +917,12 @@ qede_process_tx_compl(__rte_unused struct ecore_dev *edev,
 		nb_segs = mbuf->nb_segs;
 		remaining -= nb_segs;
 
+		/* Prefetch the next mbuf. Note that at least the last 4 mbufs
+		 * that are prefetched will not be used in the current call.
+		 */
+		rte_mbuf_prefetch_part1(txq->sw_tx_ring[(idx + 4) & mask]);
+		rte_mbuf_prefetch_part2(txq->sw_tx_ring[(idx + 4) & mask]);
+
 		PMD_TX_LOG(DEBUG, txq, "nb_segs to free %u\n", nb_segs);
 
 		while (nb_segs) {
-- 
2.30.2