From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH v2 net-next] tcp: tcp_tso_segment() small optimization Date: Sat, 13 Apr 2013 06:22:08 -0700 Message-ID: <1365859328.4459.97.camel@edumazet-glaptop> References: <1365858859.4459.94.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev To: David Miller Return-path: Received: from mail-pd0-f172.google.com ([209.85.192.172]:40525 "EHLO mail-pd0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753206Ab3DMNWL (ORCPT ); Sat, 13 Apr 2013 09:22:11 -0400 Received: by mail-pd0-f172.google.com with SMTP id 5so1842290pdd.3 for ; Sat, 13 Apr 2013 06:22:11 -0700 (PDT) In-Reply-To: <1365858859.4459.94.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet 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 --- v2: Typo in change log : more -> move 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 963bda1..dcb116d 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),