netdev - [PATCH net-next 2/3] tcp: use MAX_TCP_HEADER in tcp_stream_alloc

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Message-Id: <20211025221342.806029-3-eric.dumazet@gmail.com>
Date:   Mon, 25 Oct 2021 15:13:41 -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>,
        Soheil Hassas Yeganeh <soheil@...gle.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Eric Dumazet <eric.dumazet@...il.com>
Subject: [PATCH net-next 2/3] tcp: use MAX_TCP_HEADER in tcp_stream_alloc_skb

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

Both IPv4 and IPv6 uses same reserve, no need risking
cache line misses to fetch its value.

Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
 net/ipv4/tcp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 68dd580dba3d0e04412466868135c49225a4a33b..121400557fde898283a8eae3b09d93479c4a089e 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -867,7 +867,7 @@ struct sk_buff *tcp_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
 	if (unlikely(tcp_under_memory_pressure(sk)))
 		sk_mem_reclaim_partial(sk);
 
-	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
+	skb = alloc_skb_fclone(size + MAX_TCP_HEADER, gfp);
 	if (likely(skb)) {
 		bool mem_scheduled;
 
@@ -878,7 +878,7 @@ struct sk_buff *tcp_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
 			mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
 		}
 		if (likely(mem_scheduled)) {
-			skb_reserve(skb, sk->sk_prot->max_header);
+			skb_reserve(skb, MAX_TCP_HEADER);
 			/*
 			 * Make sure that we have exactly size bytes
 			 * available to the caller, no more, no less.
-- 
2.33.0.1079.g6e70778dc9-goog