tcp: fix SO_RCVLOWAT possible hangs under high mem pressure (ba3bb0e7) · Commits · 戴 / test

Whenever tcp_try_rmem_schedule() returns an error, we are under trouble and should make sure to wakeup readers so that they can drain socket queues and eventually make room. Fixes: ("tcp: avoid extra wakeups for SO_RCVLOWAT users") Signed-off-by:

Eric Dumazet <edumazet@google.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv4/tcp_input.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -4582,6 +4582,7 @@ static void tcp_data_queue_ofo(struct sock sk, struct sk_buff skb)

		if (unlikely(tcp_try_rmem_schedule(sk, skb, skb->truesize))) {
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFODROP);
		sk->sk_data_ready(sk);
		tcp_drop(sk, skb);
		return;
		}
		@@ -4828,6 +4829,7 @@ queue_and_out:
		sk_forced_mem_schedule(sk, skb->truesize);
		else if (tcp_try_rmem_schedule(sk, skb, skb->truesize)) {
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVQDROP);
		sk->sk_data_ready(sk);
		goto drop;
		}

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