From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neal Cardwell Subject: Re: [PATCH] tcp: undo spurious timeout after SACK reneging Date: Sun, 24 Mar 2013 16:50:41 -0400 Message-ID: References: <1364157745-24866-1-git-send-email-ycheng@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: David Miller , Eric Dumazet , Nandita Dukkipati , Netdev To: Yuchung Cheng Return-path: Received: from mail-ea0-f178.google.com ([209.85.215.178]:48859 "EHLO mail-ea0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754511Ab3CXUum (ORCPT ); Sun, 24 Mar 2013 16:50:42 -0400 Received: by mail-ea0-f178.google.com with SMTP id g14so2127014eak.9 for ; Sun, 24 Mar 2013 13:50:41 -0700 (PDT) In-Reply-To: <1364157745-24866-1-git-send-email-ycheng@google.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, Mar 24, 2013 at 4:42 PM, Yuchung Cheng wrote: > 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 > --- > net/ipv4/tcp_input.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) Acked-by: Neal Cardwell neal