From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH net-next] tcp: properly send new data in fast recovery in first RTT Date: Tue, 11 Jun 2013 20:57:55 -0700 Message-ID: <1371009475.3252.53.camel@edumazet-glaptop> References: <1370990132-27652-1-git-send-email-ycheng@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Yuchung Cheng , David Miller , Eric Dumazet , Nandita Dukkipati , Netdev To: Neal Cardwell Return-path: Received: from mail-ea0-f178.google.com ([209.85.215.178]:62219 "EHLO mail-ea0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751252Ab3FLD6A (ORCPT ); Tue, 11 Jun 2013 23:58:00 -0400 Received: by mail-ea0-f178.google.com with SMTP id l15so4497967eak.37 for ; Tue, 11 Jun 2013 20:57:59 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 2013-06-11 at 19:56 -0400, Neal Cardwell wrote: > On Tue, Jun 11, 2013 at 6:35 PM, Yuchung Cheng wrote: > > Linux sends new unset data during disorder and recovery state if all > > (suspected) lost packets have been retransmitted ( RFC5681, section > > 3.2 step 1 & 2, RFC3517 section 4, NexSeg() Rule 2). One requirement > > is to keep the receive window about twice the estimated sender's > > congestion window (tcp_rcv_space_adjust()), assuming the fast > > retransmits repair the losses in the next round trip. > > > > But currently it's not the case on the first round trip in either > > normal or Fast Open connection, beucase the initial receive window > > is identical to (expected) sender's initial congestion window. The > > fix is to double it. > > > > Signed-off-by: Yuchung Cheng > > Acked-by: Neal Cardwell Yes, this is indeed a very nice catch, thanks Yuchung ! Acked-by: Eric Dumazet