From dfd4f0ae2e111e2b93c295938c0e64ebbb69ae6e Mon Sep 17 00:00:00 2001
From: Eric Dumazet <dada1@cosmosbay.com>
Date: Fri, 21 Dec 2007 06:07:53 -0800
Subject: [PATCH] [TCP]: Avoid two divides in __tcp_grow_window()
tcp_win_from_space() being signed, compiler might emit an integer divide
to compute tcp_win_from_space()/2 .
Using right shifts is OK here and less expensive.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/tcp_input.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index bc2d5f70966eb..519bd24e0d3b7 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -289,8 +289,8 @@ static int __tcp_grow_window(const struct sock *sk, const struct sk_buff *skb)
{
struct tcp_sock *tp = tcp_sk(sk);
/* Optimize this! */
- int truesize = tcp_win_from_space(skb->truesize)/2;
- int window = tcp_win_from_space(sysctl_tcp_rmem[2])/2;
+ int truesize = tcp_win_from_space(skb->truesize) >> 1;
+ int window = tcp_win_from_space(sysctl_tcp_rmem[2]) >> 1;
while (tp->rcv_ssthresh <= window) {
if (truesize <= skb->len)
--
GitLab