netdev - [PATCH net-next] tcp: avoid indirect call in tcp_new

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Date:   Wed, 21 Jul 2021 02:06:14 -0700
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     "David S . Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>
Cc:     netdev <netdev@...r.kernel.org>,
        Eric Dumazet <edumazet@...gle.com>,
        Eric Dumazet <eric.dumazet@...il.com>
Subject: [PATCH net-next] tcp: avoid indirect call in tcp_new_space()

From: Eric Dumazet <edumazet@...gle.com>

For tcp sockets, sk->sk_write_space is most probably sk_stream_write_space().

Other sk->sk_write_space() calls in TCP are slow path and do not deserve
any change.

Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
 net/ipv4/tcp_input.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 149ceb5c94ffcd4499d3054fae31bd296a9e0bcd..bef2c8b64d83a0f3d4cca90f9b12912bf3d00807 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5383,7 +5383,7 @@ static void tcp_new_space(struct sock *sk)
 		tp->snd_cwnd_stamp = tcp_jiffies32;
 	}
 
-	sk->sk_write_space(sk);
+	INDIRECT_CALL_1(sk->sk_write_space, sk_stream_write_space, sk);
 }
 
 static void tcp_check_space(struct sock *sk)
-- 
2.32.0.402.g57bb445576-goog