Commit e7c89ae4 authored Apr 15, 2022 by Eric Dumazet Committed by David S. Miller Apr 17, 2022

tcp: add drop reason support to tcp_prune_ofo_queue()



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

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 4b506af9

include/linux/skbuff.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

include/trace/events/skb.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -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) \

net/ipv4/tcp_input.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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 &&