[dpdk-dev] [PATCH v3] test/pmd_perf: fix the way to drain the port

[Julien Meunier <julien.meunier@nokia.com>]

If the port has received less than ``pkt_per_port`` packets (for
example, the port has missed some packets), the test is in an infinite
loop.

Instead of expecting a number of packet to receive, let the port to be
drained by itself. If no more packets are received, the test can
continue.

Fixes: 002ade70e933 ("app/test: measure cycles per packet in Rx/Tx")
Cc: stable@dpdk.org

Signed-off-by: Julien Meunier <julien.meunier@nokia.com>
---
v3:
* add timeout on stop
* add log details
v2:
* rename commit title
* fix nb_free display
---
 test/test/test_pmd_perf.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/test/test/test_pmd_perf.c b/test/test/test_pmd_perf.c
index f5095c8..ed8524a 100644
--- a/test/test/test_pmd_perf.c
+++ b/test/test/test_pmd_perf.c
@@ -493,16 +493,21 @@ main_loop(__rte_unused void *args)
 
 	for (i = 0; i < conf->nb_ports; i++) {
 		portid = conf->portlist[i];
-		int nb_free = pkt_per_port;
+		int nb_free = 0;
+		uint64_t timeout = 10000;
 		do { /* dry out */
 			nb_rx = rte_eth_rx_burst(portid, 0,
 						 pkts_burst, MAX_PKT_BURST);
 			nb_tx = 0;
 			while (nb_tx < nb_rx)
 				rte_pktmbuf_free(pkts_burst[nb_tx++]);
-			nb_free -= nb_rx;
-		} while (nb_free != 0);
-		printf("free %d mbuf left in port %u\n", pkt_per_port, portid);
+			nb_free += nb_rx;
+
+			if (unlikely(nb_rx == 0))
+				timeout--;
+		} while (nb_free != pkt_per_port && timeout != 0);
+		printf("free %d (expected %d) mbuf left in port %u\n", nb_free,
+		       pkt_per_port, portid);
 	}
 
 	if (count == 0)
-- 
2.10.2