Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935566Ab3DKVVe (ORCPT ); Thu, 11 Apr 2013 17:21:34 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:11236 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935460Ab3DKUsy (ORCPT ); Thu, 11 Apr 2013 16:48:54 -0400 X-Authority-Analysis: v=2.0 cv=F+XVh9dN c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=mrGHgKfAx7IA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=GeoeZEqiE6cA:10 a=1XWaLZrsAAAA:8 a=J1Y8HTJGAAAA:8 a=jmWCE8W1go-RpaolMxwA:9 a=UTB_XpHje0EA:10 a=4N9Db7Z2_RYA:10 a=jeBq3FmKZ4MA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-Id: <20130411202610.878036466@goodmis.org> User-Agent: quilt/0.60-1 Date: Thu, 11 Apr 2013 16:27:33 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yuchung Cheng , Neal Cardwell , "David S. Miller" Subject: [ 150/171 ] tcp: undo spurious timeout after SACK reneging References: <20130411202503.783159048@goodmis.org> Content-Disposition: inline; filename=0150-tcp-undo-spurious-timeout-after-SACK-reneging.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1557 Lines: 50 3.6.11.2 stable review patch. If anyone has any objections, please let me know. ------------------ From: Yuchung Cheng [ Upstream commit 7ebe183c6d444ef5587d803b64a1f4734b18c564 ] On SACK reneging the sender immediately retransmits and forces a timeout but disables Eifel (undo). If the (buggy) receiver does not drop any packet this can trigger a false slow-start retransmit storm driven by the ACKs of the original packets. This can be detected with undo and TCP timestamps. Signed-off-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller Signed-off-by: Steven Rostedt --- net/ipv4/tcp_input.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 396c6ae..db1b172 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2083,11 +2083,8 @@ void tcp_enter_loss(struct sock *sk, int how) if (tcp_is_reno(tp)) tcp_reset_reno_sack(tp); - if (!how) { - /* Push undo marker, if it was plain RTO and nothing - * was retransmitted. */ - tp->undo_marker = tp->snd_una; - } else { + tp->undo_marker = tp->snd_una; + if (how) { tp->sacked_out = 0; tp->fackets_out = 0; } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/