net/qede: prefetch next packet to free

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@redhat.com>
Reviewed-by: Igor Russkikh <irusskikh@marvell.com>

diff --git a/drivers/net/qede/qede_rxtx.c b/drivers/net/qede/qede_rxtx.c
index 4f58abf..ed36171 100644 (file)
--- 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) {