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From:   Yafang Shao <laoar.shao@gmail.com>
To:     davem@davemloft.net, edumazet@google.com
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH net-next] inet: minor optimization for backlog setting in listen(2)
Date:   Wed,  7 Nov 2018 19:20:16 +0800
Message-Id: <1541589617-1607-1-git-send-email-laoar.shao@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Set the backlog earlier in inet_dccp_listen() and inet_listen(),
then we can avoid the redundant setting.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 net/dccp/proto.c                | 2 +-
 net/ipv4/af_inet.c              | 2 +-
 net/ipv4/inet_connection_sock.c | 1 -
 3 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 43733ac..658cd32b 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -948,6 +948,7 @@ int inet_dccp_listen(struct socket *sock, int backlog)
 	if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 		goto out;
 
+	sk->sk_max_ack_backlog = backlog;
 	/* Really, if the socket is already in listen state
 	 * we can only allow the backlog to be adjusted.
 	 */
@@ -960,7 +961,6 @@ int inet_dccp_listen(struct socket *sock, int backlog)
 		if (err)
 			goto out;
 	}
-	sk->sk_max_ack_backlog = backlog;
 	err = 0;
 
 out:
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 1fbe2f8..39066cd 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -208,6 +208,7 @@ int inet_listen(struct socket *sock, int backlog)
 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
 		goto out;
 
+	sk->sk_max_ack_backlog = backlog;
 	/* Really, if the socket is already in listen state
 	 * we can only allow the backlog to be adjusted.
 	 */
@@ -231,7 +232,6 @@ int inet_listen(struct socket *sock, int backlog)
 			goto out;
 		tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
 	}
-	sk->sk_max_ack_backlog = backlog;
 	err = 0;
 
 out:
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 15e7f79..860e22a 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -874,7 +874,6 @@ int inet_csk_listen_start(struct sock *sk, int backlog)
 
 	reqsk_queue_alloc(&icsk->icsk_accept_queue);
 
-	sk->sk_max_ack_backlog = backlog;
 	sk->sk_ack_backlog = 0;
 	inet_csk_delack_init(sk);
 
-- 
1.8.3.1