From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754283Ab3CZRg2 (ORCPT ); Tue, 26 Mar 2013 13:36:28 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:28442 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754068Ab3CZRgO (ORCPT ); Tue, 26 Mar 2013 13:36:14 -0400 X-Authority-Analysis: v=2.0 cv=adbjbGUt c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=Zk38eq-o2OgA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=Pe9ExezKr4UA:10 a=1XWaLZrsAAAA:8 a=J1Y8HTJGAAAA:8 a=GZK3lcuhIWR5GrNAc6YA:9 a=UTB_XpHje0EA:10 a=4N9Db7Z2_RYA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-Id: <20130326173607.818227027@goodmis.org> User-Agent: quilt/0.60-1 Date: Tue, 26 Mar 2013 13:21:48 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Neal Cardwell , Eric Dumazet , "David S. Miller" Subject: [PATCH 49/86] tcp: fix double-counted receiver RTT when leaving receiver fast path References: <20130326172059.136127374@goodmis.org> Content-Disposition: inline; filename=0049-tcp-fix-double-counted-receiver-RTT-when-leaving-rec.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.6.11.1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Neal Cardwell [ Upstream commit aab2b4bf224ef8358d262f95b568b8ad0cecf0a0 ] We should not update ts_recent and call tcp_rcv_rtt_measure_ts() both before and after going to step5. That wastes CPU and double-counts the receiver-side RTT sample. Signed-off-by: Neal Cardwell Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 8d02e34..41073d2 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5525,6 +5525,9 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, if (tcp_checksum_complete_user(sk, skb)) goto csum_error; + if ((int)skb->truesize > sk->sk_forward_alloc) + goto step5; + /* Predicted packet is in window by definition. * seq == rcv_nxt and rcv_wup <= rcv_nxt. * Hence, check seq<=rcv_wup reduces to: @@ -5536,9 +5539,6 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, tcp_rcv_rtt_measure_ts(sk, skb); - if ((int)skb->truesize > sk->sk_forward_alloc) - goto step5; - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPHPHITS); /* Bulk data transfer: receiver */ -- 1.7.10.4