[PATCH net-next 07/10] tcp: add drop reason support to tcp_prune_ofo_queue()

[Eric Dumazet <eric.dumazet@gmail.com>]

From: Eric Dumazet <edumazet@google.com>

Add one reason for packets dropped from OFO queue because
of memory pressure.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/linux/skbuff.h     | 1 +
 include/trace/events/skb.h | 2 ++
 net/ipv4/tcp_input.c       | 3 ++-
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 9ff5557b190905f716a25f67113c1db822707959..ad15ad208b5612357546f23dfe4feaa1535f4982 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -392,6 +392,7 @@ enum skb_drop_reason {
 	SKB_DROP_REASON_TCP_OLD_ACK,	/* TCP ACK is old, but in window */
 	SKB_DROP_REASON_TCP_TOO_OLD_ACK, /* TCP ACK is too old */
 	SKB_DROP_REASON_TCP_ACK_UNSENT_DATA, /* TCP ACK for data we haven't sent yet */
+	SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE, /* pruned from TCP OFO queue */
 	SKB_DROP_REASON_IP_OUTNOROUTES,	/* route lookup failed */
 	SKB_DROP_REASON_BPF_CGROUP_EGRESS,	/* dropped by
 						 * BPF_PROG_TYPE_CGROUP_SKB
diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h
index eab0b09223f3c66255f930d44be61d45e83ca6e8..73d7a6e594cbc6884148afa473bc08d12d783079 100644
--- a/include/trace/events/skb.h
+++ b/include/trace/events/skb.h
@@ -48,6 +48,8 @@
 	EM(SKB_DROP_REASON_TCP_TOO_OLD_ACK, TCP_TOO_OLD_ACK)	\
 	EM(SKB_DROP_REASON_TCP_ACK_UNSENT_DATA,			\
 	   TCP_ACK_UNSENT_DATA)					\
+	EM(SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE,			\
+	  TCP_OFO_QUEUE_PRUNE)					\
 	EM(SKB_DROP_REASON_IP_OUTNOROUTES, IP_OUTNOROUTES)	\
 	EM(SKB_DROP_REASON_BPF_CGROUP_EGRESS,			\
 	   BPF_CGROUP_EGRESS)					\
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 8a68785b04053b8e622404035284920e51cd953c..a1077adeb1b62d74b5f1c9a6fc34def44ae07790 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5334,7 +5334,8 @@ static bool tcp_prune_ofo_queue(struct sock *sk)
 		prev = rb_prev(node);
 		rb_erase(node, &tp->out_of_order_queue);
 		goal -= rb_to_skb(node)->truesize;
-		tcp_drop(sk, rb_to_skb(node));
+		tcp_drop_reason(sk, rb_to_skb(node),
+				SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE);
 		if (!prev || goal <= 0) {
 			sk_mem_reclaim(sk);
 			if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
-- 
2.36.0.rc0.470.gd361397f0d-goog