[dpdk-dev] [PATCH v2] app/testpmd: add packet data pointer prefetch in the forwarding loop

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

prefetch the next packet data address in advance in forwarding loop
for performance improvement.

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
---
V2:
Extend the packet data prefetch logic to other similar forwarding modes like
macfwd, macfwd-retry, csumonly, icmpecho as suggested by Pablo
http://dpdk.org/dev/patchwork/patch/12330/
---
 app/test-pmd/csumonly.c     | 3 +++
 app/test-pmd/icmpecho.c     | 3 +++
 app/test-pmd/macfwd-retry.c | 3 +++
 app/test-pmd/macfwd.c       | 3 +++
 app/test-pmd/macswap.c      | 3 +++
 5 files changed, 15 insertions(+)

diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c
index 7e4f662..1d6cda1 100644
--- a/app/test-pmd/csumonly.c
+++ b/app/test-pmd/csumonly.c
@@ -676,6 +676,9 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 	info.tso_segsz = txp->tso_segsz;
 
 	for (i = 0; i < nb_rx; i++) {
+		if (likely(i < nb_rx - 1))
+			rte_prefetch0(rte_pktmbuf_mtod(pkts_burst[i + 1],
+						       void *));
 
 		ol_flags = 0;
 		info.is_tunnel = 0;
diff --git a/app/test-pmd/icmpecho.c b/app/test-pmd/icmpecho.c
index e510f9b..ed6e924 100644
--- a/app/test-pmd/icmpecho.c
+++ b/app/test-pmd/icmpecho.c
@@ -346,6 +346,9 @@ reply_to_icmp_echo_rqsts(struct fwd_stream *fs)
 	fs->rx_packets += nb_rx;
 	nb_replies = 0;
 	for (i = 0; i < nb_rx; i++) {
+		if (likely(i < nb_rx - 1))
+			rte_prefetch0(rte_pktmbuf_mtod(pkts_burst[i + 1],
+						       void *));
 		pkt = pkts_burst[i];
 		eth_h = rte_pktmbuf_mtod(pkt, struct ether_hdr *);
 		eth_type = RTE_BE_TO_CPU_16(eth_h->ether_type);
diff --git a/app/test-pmd/macfwd-retry.c b/app/test-pmd/macfwd-retry.c
index 3a96b3d..d8cd069 100644
--- a/app/test-pmd/macfwd-retry.c
+++ b/app/test-pmd/macfwd-retry.c
@@ -117,6 +117,9 @@ pkt_burst_mac_retry_forward(struct fwd_stream *fs)
 #endif
 	fs->rx_packets += nb_rx;
 	for (i = 0; i < nb_rx; i++) {
+		if (likely(i < nb_rx - 1))
+			rte_prefetch0(rte_pktmbuf_mtod(pkts_burst[i + 1],
+						       void *));
 		mb = pkts_burst[i];
 		eth_hdr = rte_pktmbuf_mtod(mb, struct ether_hdr *);
 		ether_addr_copy(&peer_eth_addrs[fs->peer_addr],
diff --git a/app/test-pmd/macfwd.c b/app/test-pmd/macfwd.c
index 3b7fffb..07a399a 100644
--- a/app/test-pmd/macfwd.c
+++ b/app/test-pmd/macfwd.c
@@ -113,6 +113,9 @@ pkt_burst_mac_forward(struct fwd_stream *fs)
 	if (txp->tx_ol_flags & TESTPMD_TX_OFFLOAD_INSERT_QINQ)
 		ol_flags |= PKT_TX_QINQ_PKT;
 	for (i = 0; i < nb_rx; i++) {
+		if (likely(i < nb_rx - 1))
+			rte_prefetch0(rte_pktmbuf_mtod(pkts_burst[i + 1],
+						       void *));
 		mb = pkts_burst[i];
 		eth_hdr = rte_pktmbuf_mtod(mb, struct ether_hdr *);
 		ether_addr_copy(&peer_eth_addrs[fs->peer_addr],
diff --git a/app/test-pmd/macswap.c b/app/test-pmd/macswap.c
index 154889d..c10f4b5 100644
--- a/app/test-pmd/macswap.c
+++ b/app/test-pmd/macswap.c
@@ -113,6 +113,9 @@ pkt_burst_mac_swap(struct fwd_stream *fs)
 	if (txp->tx_ol_flags & TESTPMD_TX_OFFLOAD_INSERT_QINQ)
 		ol_flags |= PKT_TX_QINQ_PKT;
 	for (i = 0; i < nb_rx; i++) {
+		if (likely(i < nb_rx - 1))
+			rte_prefetch0(rte_pktmbuf_mtod(pkts_burst[i + 1],
+						       void *));
 		mb = pkts_burst[i];
 		eth_hdr = rte_pktmbuf_mtod(mb, struct ether_hdr *);
 
-- 
2.1.0