Re: [PATCH net-next] __udp_enqueue_schedule_skb() drops packets when there is no buffer space available, but currently does not update UDP SNMP counters.
flat view
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: 2026-01-07 15:44:02
Kshitiz Bartariya wrote:
Update UDP_MIB_MEMERRORS and UDP_MIB_INERRORS when packets are dropped due to memory pressure, for both UDP and UDPLite sockets. This removes a long-standing TODO and makes UDP statistics consistent with actual drop behavior. Signed-off-by: Kshitiz Bartariya <redacted>
This is addressing the same open TODO as the patch under review https://lore.kernel.org/netdev/20260105114732.140719-1-mahdifrmx@gmail.com/ (local) It does so in the single basic block, as suggested here https://lore.kernel.org/netdev/willemdebruijn.kernel.21c4d3b7b8f9d@gmail.com/ (local) But these updates are expensive, so better to batch them as in the other patch.
quoted hunk ↗ jump to hunk
--- net/ipv4/udp.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 9c87067c74bc..66c06f468240 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c@@ -1794,11 +1794,16 @@ int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) } if (unlikely(to_drop)) { + const bool is_udplite = IS_UDPLITE(sk); + for (nb = 0; to_drop != NULL; nb++) { skb = to_drop; to_drop = skb->next; skb_mark_not_on_list(skb); - /* TODO: update SNMP values. */ + + UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS, is_udplite); + UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); + sk_skb_reason_drop(sk, skb, SKB_DROP_REASON_PROTO_MEM); } numa_drop_add(&udp_sk(sk)->drop_counters, nb);-- 2.50.1 (Apple Git-155)