netdev: add queue stat for alloc failures

Rx alloc failures are commonly counted by drivers.
Support reporting those via netdev-genl queue stats.

Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Amritha Nambiar <amritha.nambiar@intel.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240306195509.1502746-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index a1e48c3c84c9618d0dfb571241834c9298ed8210..76352dbd2be4eb71ea192cb162dd00803005907b 100644 (file)
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -328,6 +328,13 @@ attribute-sets:
         name: tx-bytes
         doc: Successfully sent bytes, see `tx-packets`.
         type: uint
+      -
+        name: rx-alloc-fail
+        doc: |
+          Number of times skb or buffer allocation failed on the Rx datapath.
+          Allocation failure may, or may not result in a packet drop, depending
+          on driver implementation and whether system recovers quickly.
+        type: uint
 
 operations:
   list:

diff --git a/include/net/netdev_queues.h b/include/net/netdev_queues.h
index d633347eeda5944aa76ef13756d82f3b8bbf8636..1ec4085853738de943107d23c140ca4543f5b5d4 100644 (file)
--- a/include/net/netdev_queues.h
+++ b/include/net/netdev_queues.h
@@ -4,9 +4,11 @@
 
 #include <linux/netdevice.h>
 
+/* See the netdev.yaml spec for definition of each statistic */
 struct netdev_queue_stats_rx {
        u64 bytes;
        u64 packets;
+       u64 alloc_fail;
 };
 
 struct netdev_queue_stats_tx {

diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 639ffa04c172c69b7816c1530ffc2221c6237627..bb65ee840cdac88d4f853775ef3871afee600ef7 100644 (file)
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -145,6 +145,7 @@ enum {
        NETDEV_A_QSTATS_RX_BYTES,
        NETDEV_A_QSTATS_TX_PACKETS,
        NETDEV_A_QSTATS_TX_BYTES,
+       NETDEV_A_QSTATS_RX_ALLOC_FAIL,
 
        __NETDEV_A_QSTATS_MAX,
        NETDEV_A_QSTATS_MAX = (__NETDEV_A_QSTATS_MAX - 1)

diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 7fa75e13dc6da1d5cfed9380c0eeea7ced161d2b..7004b3399c2b0e045ace5222c6b1628c0cf81d87 100644 (file)
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -488,7 +488,8 @@ static int
 netdev_nl_stats_write_rx(struct sk_buff *rsp, struct netdev_queue_stats_rx *rx)
 {
        if (netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_PACKETS, rx->packets) ||
-           netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_BYTES, rx->bytes))
+           netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_BYTES, rx->bytes) ||
+           netdev_stat_put(rsp, NETDEV_A_QSTATS_RX_ALLOC_FAIL, rx->alloc_fail))
                return -EMSGSIZE;
        return 0;
 }

diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index 639ffa04c172c69b7816c1530ffc2221c6237627..bb65ee840cdac88d4f853775ef3871afee600ef7 100644 (file)
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -145,6 +145,7 @@ enum {
        NETDEV_A_QSTATS_RX_BYTES,
        NETDEV_A_QSTATS_TX_PACKETS,
        NETDEV_A_QSTATS_TX_BYTES,
+       NETDEV_A_QSTATS_RX_ALLOC_FAIL,
 
        __NETDEV_A_QSTATS_MAX,
        NETDEV_A_QSTATS_MAX = (__NETDEV_A_QSTATS_MAX - 1)