From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Yan, Zheng" Subject: [PATCH v3] tcp: properly update lost_cnt_hint during shifting Date: Sun, 02 Oct 2011 22:21:50 +0800 Message-ID: <4E88737E.5030906@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: "netdev@vger.kernel.org" , =?ISO-8859-1?Q?Ilpo_J=E4rvinen?= , Nandita Dukkipati , ycheng@google.com, "davem@dav Return-path: Received: from mga02.intel.com ([134.134.136.20]:44977 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752590Ab1JBOWF (ORCPT ); Sun, 2 Oct 2011 10:22:05 -0400 Sender: netdev-owner@vger.kernel.org List-ID: lost_skb_hint is used by tcp_mark_head_lost() to mark the first unhandled skb. lost_cnt_hint is the number of packets or sacked packets before the lost_skb_hint; When shifting a skb that is before the lost_skb_hint, if tcp_is_fack() is ture, the skb has already been counted in the lost_cnt_hint; if tcp_is_fack() is false, tcp_sacktag_one() will increase the lost_cnt_hint. So tcp_shifted_skb() does not need to adjust the lost_cnt_hint by itself. When shifting a skb that is equal to lost_skb_hint, the shifted packets will not be counted by tcp_mark_head_lost(). So tcp_shifted_skb() should adjust the lost_cnt_hint even tcp_is_fack(tp) is true. Signed-off-by: Zheng Yan --- Changes since v2: adjust the lost_cnt_hint even tcp_is_fack(tp) is true. net/ipv4/tcp_input.c | 4 +--- 1 files changed, 1 insertions(+), 3 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 21fab3e..d73aab3 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1389,9 +1389,7 @@ static int tcp_shifted_skb(struct sock *sk, struct sk_buff *skb, BUG_ON(!pcount); - /* Tweak before seqno plays */ - if (!tcp_is_fack(tp) && tcp_is_sack(tp) && tp->lost_skb_hint && - !before(TCP_SKB_CB(tp->lost_skb_hint)->seq, TCP_SKB_CB(skb)->seq)) + if (skb == tp->lost_skb_hint) tp->lost_cnt_hint += pcount; TCP_SKB_CB(prev)->end_seq += shifted; -- 1.7.4.4