From bece1b9708434b6fb90b029affc228fc21688404 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 13 Apr 2013 03:22:08 +0000 Subject: [PATCH] tcp: tcp_tso_segment() small optimization We can move th->check computation out of the loop, as compiler doesn't know each skb initially share same tcp headers after skb_segment() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 963bda18486f..dcb116dde216 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2886,6 +2886,7 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, unsigned int oldlen; unsigned int mss; struct sk_buff *gso_skb = skb; + __sum16 newcheck; if (!pskb_may_pull(skb, sizeof(*th))) goto out; @@ -2936,11 +2937,13 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, th = tcp_hdr(skb); seq = ntohl(th->seq); + newcheck = ~csum_fold((__force __wsum)((__force u32)th->check + + (__force u32)delta)); + do { th->fin = th->psh = 0; + th->check = newcheck; - th->check = ~csum_fold((__force __wsum)((__force u32)th->check + - (__force u32)delta)); if (skb->ip_summed != CHECKSUM_PARTIAL) th->check = csum_fold(csum_partial(skb_transport_header(skb), -- 2.20.1