[PATCH v2 1/9] app/testpmd: fix Tx preparation in checksum engine

[David Marchand <david.marchand@redhat.com>]

"unprepared" packets could get to the wire in the retry loop.

Split packets freeing in two stages: one for preparation failure, and
one for transmission failure.
Adjust dropped counter update accordingly.

Fixes: 6b520d54ebfe ("app/testpmd: use Tx preparation in checksum engine")
Cc: stable@dpdk.org

Signed-off-by: David Marchand <david.marchand@redhat.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@amd.com>
---
 app/test-pmd/csumonly.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c
index 1c24598515..90a59e0aa5 100644
--- a/app/test-pmd/csumonly.c
+++ b/app/test-pmd/csumonly.c
@@ -1168,10 +1168,13 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 
 	nb_prep = rte_eth_tx_prepare(fs->tx_port, fs->tx_queue,
 			tx_pkts_burst, nb_rx);
-	if (nb_prep != nb_rx)
+	if (nb_prep != nb_rx) {
 		fprintf(stderr,
 			"Preparing packet burst to transmit failed: %s\n",
 			rte_strerror(rte_errno));
+		fs->fwd_dropped += (nb_rx - nb_prep);
+		rte_pktmbuf_free_bulk(&tx_pkts_burst[nb_prep], nb_rx - nb_prep);
+	}
 
 	nb_tx = rte_eth_tx_burst(fs->tx_port, fs->tx_queue, tx_pkts_burst,
 			nb_prep);
@@ -1179,12 +1182,12 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 	/*
 	 * Retry if necessary
 	 */
-	if (unlikely(nb_tx < nb_rx) && fs->retry_enabled) {
+	if (unlikely(nb_tx < nb_prep) && fs->retry_enabled) {
 		retry = 0;
-		while (nb_tx < nb_rx && retry++ < burst_tx_retry_num) {
+		while (nb_tx < nb_prep && retry++ < burst_tx_retry_num) {
 			rte_delay_us(burst_tx_delay_time);
 			nb_tx += rte_eth_tx_burst(fs->tx_port, fs->tx_queue,
-					&tx_pkts_burst[nb_tx], nb_rx - nb_tx);
+					&tx_pkts_burst[nb_tx], nb_prep - nb_tx);
 		}
 	}
 	fs->tx_packets += nb_tx;
@@ -1194,11 +1197,11 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 	fs->rx_bad_outer_ip_csum += rx_bad_outer_ip_csum;
 
 	inc_tx_burst_stats(fs, nb_tx);
-	if (unlikely(nb_tx < nb_rx)) {
-		fs->fwd_dropped += (nb_rx - nb_tx);
+	if (unlikely(nb_tx < nb_prep)) {
+		fs->fwd_dropped += (nb_prep - nb_tx);
 		do {
 			rte_pktmbuf_free(tx_pkts_burst[nb_tx]);
-		} while (++nb_tx < nb_rx);
+		} while (++nb_tx < nb_prep);
 	}
 
 	get_end_cycles(fs, start_tsc);
-- 
2.39.2