netdev: Add queue stats for TX stop and wake

TX queue stop and wake are counted by some drivers.
Support reporting these via netdev-genl queue stats.
Signed-off-by: Daniel Jurgens <danielj@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/r/20240510201927.1821109-2-danielj@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/netlink/specs/netdev.yaml

@@ -439,6 +439,20 @@ attribute-sets:
           Number of the packets dropped by the device due to the transmit
           packets bitrate exceeding the device rate limit.
         type: uint
+      -
+        name: tx-stop
+        doc: |
+          Number of times driver paused accepting new tx packets
+          from the stack to this queue, because the queue was full.
+          Note that if BQL is supported and enabled on the device
+          the networking stack will avoid queuing a lot of data at once.
+        type: uint
+      -
+        name: tx-wake
+        doc: |
+          Number of times driver re-started accepting send
+          requests to this queue from the stack.
+        type: uint
 
 operations:
   list:

include/net/netdev_queues.h

@@ -41,6 +41,9 @@ struct netdev_queue_stats_tx {
 	u64 hw_gso_wire_bytes;
 
 	u64 hw_drop_ratelimits;
+
+	u64 stop;
+	u64 wake;
 };
 
 /**

include/uapi/linux/netdev.h

@@ -165,6 +165,8 @@ enum {
 	NETDEV_A_QSTATS_TX_HW_GSO_WIRE_PACKETS,
 	NETDEV_A_QSTATS_TX_HW_GSO_WIRE_BYTES,
 	NETDEV_A_QSTATS_TX_HW_DROP_RATELIMITS,
+	NETDEV_A_QSTATS_TX_STOP,
+	NETDEV_A_QSTATS_TX_WAKE,
 
 	__NETDEV_A_QSTATS_MAX,
 	NETDEV_A_QSTATS_MAX = (__NETDEV_A_QSTATS_MAX - 1)

net/core/netdev-genl.c

@@ -517,7 +517,9 @@ netdev_nl_stats_write_tx(struct sk_buff *rsp, struct netdev_queue_stats_tx *tx)
 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_GSO_BYTES, tx->hw_gso_bytes) ||
 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_GSO_WIRE_PACKETS, tx->hw_gso_wire_packets) ||
 	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_GSO_WIRE_BYTES, tx->hw_gso_wire_bytes) ||
-	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_DROP_RATELIMITS, tx->hw_drop_ratelimits))
+	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_HW_DROP_RATELIMITS, tx->hw_drop_ratelimits) ||
+	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_STOP, tx->stop) ||
+	    netdev_stat_put(rsp, NETDEV_A_QSTATS_TX_WAKE, tx->wake))
 		return -EMSGSIZE;
 	return 0;
 }

tools/include/uapi/linux/netdev.h

@@ -165,6 +165,8 @@ enum {
 	NETDEV_A_QSTATS_TX_HW_GSO_WIRE_PACKETS,
 	NETDEV_A_QSTATS_TX_HW_GSO_WIRE_BYTES,
 	NETDEV_A_QSTATS_TX_HW_DROP_RATELIMITS,
+	NETDEV_A_QSTATS_TX_STOP,
+	NETDEV_A_QSTATS_TX_WAKE,
 
 	__NETDEV_A_QSTATS_MAX,
 	NETDEV_A_QSTATS_MAX = (__NETDEV_A_QSTATS_MAX - 1)