[dpdk-dev] [PATCH v3] app/flow-perf: fix condition of hairpin queues setup

[Wisam Jaddo]

The hairpin queue is the one that start from normal rxq,
and will be less than nr_queues where nr_queues is the
sum of normal and hairpin

Fixes: bf3688f1e816 ("app/flow-perf: add insertion rate calculation")
Cc: wis...@mellanox.com

Signed-off-by: Wisam Jaddo <wis...@mellanox.com>
Reviewed-by: Asaf Penso <as...@mellanox.com>

---
v3:
* Add variable documentation variable declaration.

v2:
* Add documentation of hairpin peering and allocating logic.
* Add documentation for some variables.
---
 app/test-flow-perf/main.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/app/test-flow-perf/main.c b/app/test-flow-perf/main.c
index e155e49c37..2200767e0d 100644
--- a/app/test-flow-perf/main.c
+++ b/app/test-flow-perf/main.c
@@ -59,6 +59,13 @@ static struct rte_mempool *mbuf_mp;
 static uint32_t nb_lcores;
 static uint32_t flows_count;
 static uint32_t iterations_number;
+/*
+ * hairpinq: represent the number of hairpin queues needed
+ * to be initialized.
+ *
+ * In 0 case means no hairpin queues needed which is the
+ * default.
+ */
 static uint32_t hairpinq;
 static uint32_t nb_lcores;
 
@@ -929,6 +936,7 @@ init_port(void)
 {
        int ret;
        uint16_t std_queue;
+       /* hairpin_q represent hairpin queue id to be initialized. */
        uint16_t hairpin_q;
        uint16_t port_id;
        uint16_t nr_ports;
@@ -1012,8 +1020,19 @@ init_port(void)
                                rte_strerror(-ret), port_id);
 
                if (hairpinq != 0) {
+                       /*
+                        * Each hairpin queue setup need a hairpin configuration
+                        * object, which determine the TX path for hairpin.
+                        *
+                        * The peering here represent the TX side, which mean 
the
+                        * peer.port represent TX port, and peer.queue represent
+                        * tx_queue.
+                        *
+                        * So if RXQ=4 and TXQ=4, and first hairpin_q is 4 after
+                        * [0, 1, 2, 3], then tx_queue is TXQ+i which is 4 as 
well.
+                        */
                        for (hairpin_q = RXQ_NUM, std_queue = 0;
-                                       std_queue < nr_queues;
+                                       hairpin_q < nr_queues;
                                        hairpin_q++, std_queue++) {
                                hairpin_conf.peers[0].port = port_id;
                                hairpin_conf.peers[0].queue =
@@ -1028,7 +1047,7 @@ init_port(void)
                        }
 
                        for (hairpin_q = TXQ_NUM, std_queue = 0;
-                                       std_queue < nr_queues;
+                                       hairpin_q < nr_queues;
                                        hairpin_q++, std_queue++) {
                                hairpin_conf.peers[0].port = port_id;
                                hairpin_conf.peers[0].queue =
-- 
2.17.1