From: Eric Dumazet Date: Fri, 21 Dec 2007 14:07:53 +0000 (-0800) Subject: [TCP]: Avoid two divides in __tcp_grow_window() X-Git-Tag: v2.6.25-rc1~1162^2~924 X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=dfd4f0ae2e111e2b93c295938c0e64ebbb69ae6e;p=linux-2.6-omap-h63xx.git [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 Signed-off-by: David S. Miller --- 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)