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authorEric Dumazet <dada1@cosmosbay.com>2007-12-21 06:07:53 -0800
committerDavid S. Miller <davem@davemloft.net>2008-01-28 15:00:01 -0800
commitdfd4f0ae2e111e2b93c295938c0e64ebbb69ae6e (patch)
tree0ce2c35f0ffce2553d897116e9370fdaf0433f12
parent8beb5c5f12c8484c59edf9b691f2c4bb4d31f3a0 (diff)
[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>
-rw-r--r--net/ipv4/tcp_input.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index bc2d5f70966..519bd24e0d3 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)