[dpdk-dev] [PATCH] fix repopulation of tx_mbufs table

[Rafal Kozik <rk@semihalf.com>]

If in one TX cycle NIC does not send any packet, pktgen tries
to allocate 0 mbufs from pool. In such case DPDK return error
and packets will not be send. As no packet will be send in
next iteration this situation will repeat.

Checking if taking more mbufs is needed will prevent this situation.

Fixes: f034b381d19f ("cleanup and fix for FVL NIC performance")

Signed-off-by: Rafal Kozik <rk@semihalf.com>
---
 app/pktgen.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/app/pktgen.c b/app/pktgen.c
index 2d9ff59..b4d3dfe 100644
--- a/app/pktgen.c
+++ b/app/pktgen.c
@@ -1054,7 +1054,8 @@ pktgen_send_pkts(port_info_t *info, uint16_t qid, struct rte_mempool *mp)
 		uint16_t saved = info->q[qid].tx_mbufs.len;
 		uint16_t nb_pkts = info->tx_burst - saved;
 
-		rc = pg_pktmbuf_alloc_bulk(mp,
+		if (likely(nb_pkts > 0))
+			rc = pg_pktmbuf_alloc_bulk(mp,
 		                           &info->q[qid].tx_mbufs.m_table[saved],
 		                           nb_pkts);
 		if (rc == 0) {
@@ -1070,7 +1071,8 @@ pktgen_send_pkts(port_info_t *info, uint16_t qid, struct rte_mempool *mp)
 			uint16_t saved = info->q[qid].tx_mbufs.len;
 			uint16_t nb_pkts = txCnt - saved;
 
-			rc = pg_pktmbuf_alloc_bulk(mp,
+			if (likely(nb_pkts > 0))
+				rc = pg_pktmbuf_alloc_bulk(mp,
 			                           &info->q[qid].tx_mbufs.m_table[saved],
 			                           nb_pkts);
 			if (rc == 0) {
-- 
2.7.4