[dpdk-dev] [PATCH 7/8] net/qede: prefetch next packet to free

[Balazs Nemeth]

While handling the current mbuf, pull the next 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>
---
 drivers/net/qede/qede_rxtx.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/qede/qede_rxtx.c b/drivers/net/qede/qede_rxtx.c
index b74a1ec1b..e89498811 100644
--- a/drivers/net/qede/qede_rxtx.c
+++ b/drivers/net/qede/qede_rxtx.c
@@ -915,6 +915,11 @@ 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) {
-- 
2.29.2