[dpdk-stable] patch 'net/i40e: fix mbuf free in vector Tx' has been queued to stable release 17.08.1

[Yuanhan Liu]

Hi,

FYI, your patch has been queued to stable release 17.08.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/24/17. So please
shout if anyone has objections.

Thanks.

	--yliu

---
>From 5186fb1a5e511c316317c6ae1aa1cbb5f301dc6f Mon Sep 17 00:00:00 2001
From: Qi Zhang <qi.z.zhang at intel.com>
Date: Tue, 10 Oct 2017 09:22:05 -0400
Subject: [PATCH] net/i40e: fix mbuf free in vector Tx

[ upstream commit 24853544c84c152dabcd013b9ee723a059e0d5dd ]

vPMD tx does not set sw_ring's mbuf to NULL after free.
Therefore, in cases where the vector transmit function is in
use, we must use the appropriate index and threshold values
for the queue to only free the unreleased mbufs

Fixes: b4669bb95038 ("i40e: add vector Tx")

Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>
Acked-by: Bruce Richardson <bruce.richardson at intel.com>
---
 drivers/net/i40e/i40e_rxtx.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index 3a7b68e..f3d1c10 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -2309,18 +2309,40 @@ i40e_reset_rx_queue(struct i40e_rx_queue *rxq)
 void
 i40e_tx_queue_release_mbufs(struct i40e_tx_queue *txq)
 {
+	struct rte_eth_dev *dev;
 	uint16_t i;
 
+	dev = &rte_eth_devices[txq->port_id];
+
 	if (!txq || !txq->sw_ring) {
 		PMD_DRV_LOG(DEBUG, "Pointer to rxq or sw_ring is NULL");
 		return;
 	}
 
-	for (i = 0; i < txq->nb_tx_desc; i++) {
-		if (txq->sw_ring[i].mbuf) {
+	/**
+	 *  vPMD tx will not set sw_ring's mbuf to NULL after free,
+	 *  so need to free remains more carefully.
+	 */
+	if (dev->tx_pkt_burst == i40e_xmit_pkts_vec) {
+		i = txq->tx_next_dd - txq->tx_rs_thresh + 1;
+		if (txq->tx_tail < i) {
+			for (; i < txq->nb_tx_desc; i++) {
+				rte_pktmbuf_free_seg(txq->sw_ring[i].mbuf);
+				txq->sw_ring[i].mbuf = NULL;
+			}
+			i = 0;
+		}
+		for (; i < txq->tx_tail; i++) {
 			rte_pktmbuf_free_seg(txq->sw_ring[i].mbuf);
 			txq->sw_ring[i].mbuf = NULL;
 		}
+	} else {
+		for (i = 0; i < txq->nb_tx_desc; i++) {
+			if (txq->sw_ring[i].mbuf) {
+				rte_pktmbuf_free_seg(txq->sw_ring[i].mbuf);
+				txq->sw_ring[i].mbuf = NULL;
+			}
+		}
 	}
 }
 
-- 
2.7.4