[ovs-dev] [PATCH 2/2] netdev-dpdk: Expose per rxq/txq basic statistics.

[David Marchand]

When troubleshooting multiqueue setups, having per queue statistics helps
checking packets repartition in rx and tx queues.

Per queue statistics are exported by most DPDK drivers (with capability
RTE_ETH_DEV_AUTOFILL_QUEUE_XSTATS).
OVS only filters DPDK statistics, there is nothing to request in DPDK API.
So the only change is to extend the filter on xstats.

Querying statistics with
$ ovs-vsctl get interface dpdk0 statistics |
  sed -e 's#[{}]##g' -e 's#, #\n#g'

and comparing gives:
@@ -13,7 +13,12 @@
 rx_phy_crc_errors=0
 rx_phy_in_range_len_errors=0
 rx_phy_symbol_errors=0
+rx_q0_bytes=0
 rx_q0_errors=0
+rx_q0_packets=0
+rx_q1_bytes=0
 rx_q1_errors=0
+rx_q1_packets=0
 rx_wqe_errors=0
 tx_broadcast_packets=0
 tx_bytes=0
@@ -27,3 +32,13 @@
 tx_pp_rearm_queue_errors=0
 tx_pp_timestamp_future_errors=0
 tx_pp_timestamp_past_errors=0
+tx_q0_bytes=0
+tx_q0_packets=0
+tx_q1_bytes=0
+tx_q1_packets=0
+tx_q2_bytes=0
+tx_q2_packets=0
+tx_q3_bytes=0
+tx_q3_packets=0
+tx_q4_bytes=0
+tx_q4_packets=0

Signed-off-by: David Marchand <david.marchand at redhat.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
Changes since RFC:
- dropped regex and used simpler string manipulations,

---
 lib/netdev-dpdk.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index 51bb41551b..1e6079d544 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -1582,6 +1582,16 @@ netdev_dpdk_get_xstat_name(struct netdev_dpdk *dev, uint64_t id)
     return dev->rte_xstats_names[id].name;
 }
 
+static bool
+is_queue_stat(const char *s)
+{
+    uint16_t tmp;
+
+    return (s[0] == 'r' || s[0] == 't') &&
+            (ovs_scan(s + 1, "x_q%"SCNu16"_packets", &tmp) ||
+             ovs_scan(s + 1, "x_q%"SCNu16"_bytes", &tmp));
+}
+
 static void
 netdev_dpdk_configure_xstats(struct netdev_dpdk *dev)
     OVS_REQUIRES(dev->mutex)
@@ -1632,9 +1642,10 @@ netdev_dpdk_configure_xstats(struct netdev_dpdk *dev)
         id = rte_xstats[i].id;
         name = netdev_dpdk_get_xstat_name(dev, id);
 
-        /* We need to filter out everything except dropped, error and
-         * management counters. */
-        if (string_ends_with(name, "_errors") ||
+        /* For custom stats, we filter out everything except per rxq/txq basic
+         * stats, and dropped, error and management counters. */
+        if (is_queue_stat(name) ||
+            string_ends_with(name, "_errors") ||
             strstr(name, "_management_") ||
             string_ends_with(name, "_dropped")) {
 
-- 
2.23.0