[dpdk-stable] [PATCH V2 1/7] app/testpmd: fix forward lcores number when dcb test

[Huisong Li]

Currently, 'nb_fwd_lcores' value are both adjusted based on
'nb_fwd_streams' in rss/simple/icmp_echo_fwd_config_setup.
But the operation is missing in dcb_fwd_config_setup, which
may lead to a bad behavior in which multiple polling threads
operate on the same queue. In this case, the device sends and
receives packets, causing unexpected results. The procedure is
 as follows:
1/ run testpmd with "--rxq=8 --txq=8"
2/ port stop all
3/ set nbcore 8
4/ port config 0 dcb vt off 4 pfc on
5/ port config all rxq 16
6/ port config all txq 16
7/ port start all
8/ set fwd mac
9/ start

For the DCB forwarding test, each core is assigned to each
traffic class and each core is assigned a multi-stream.
Therefore, 'nb_fwd_lcores' value needs to be adjusted based
 on 'total_tc_num' in all forwarding ports.

Fixes: 900550de04a7 ("app/testpmd: add dcb support")
Fixes: ce8d561418d4 ("app/testpmd: add port configuration settings")
Cc: stable at dpdk.org

Signed-off-by: Huisong Li <lihuisong at huawei.com>
---
 app/test-pmd/config.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index ccb9bd3..03ee40c 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -2961,6 +2961,21 @@ rss_fwd_config_setup(void)
 	}
 }
 
+static uint16_t
+get_fwd_port_total_tc_num(void)
+{
+	struct rte_eth_dcb_info dcb_info;
+	uint16_t total_tc_num = 0;
+	unsigned int i;
+
+	for (i = 0; i < nb_fwd_ports; i++) {
+		(void)rte_eth_dev_get_dcb_info(fwd_ports_ids[i], &dcb_info);
+		total_tc_num += dcb_info.nb_tcs;
+	}
+
+	return total_tc_num;
+}
+
 /**
  * For the DCB forwarding test, each core is assigned on each traffic class.
  *
@@ -2980,12 +2995,16 @@ dcb_fwd_config_setup(void)
 	lcoreid_t  lc_id;
 	uint16_t nb_rx_queue, nb_tx_queue;
 	uint16_t i, j, k, sm_id = 0;
+	uint16_t total_tc_num;
 	uint8_t tc = 0;
 
 	cur_fwd_config.nb_fwd_lcores = (lcoreid_t) nb_fwd_lcores;
 	cur_fwd_config.nb_fwd_ports = nb_fwd_ports;
 	cur_fwd_config.nb_fwd_streams =
 		(streamid_t) (nb_rxq * cur_fwd_config.nb_fwd_ports);
+	total_tc_num = get_fwd_port_total_tc_num();
+	if (cur_fwd_config.nb_fwd_lcores > total_tc_num)
+		cur_fwd_config.nb_fwd_lcores = total_tc_num;
 
 	/* reinitialize forwarding streams */
 	init_fwd_streams();
-- 
2.7.4