From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next v2 00/13] tcp: RACK fast recovery Date: Fri, 13 Jan 2017 23:19:42 -0500 (EST) Message-ID: <20170113.231942.649931559969853825.davem@davemloft.net> References: <20170113061142.127344-1-ycheng@google.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, edumazet@google.com, ncardwell@google.com, nanditad@google.com To: ycheng@google.com Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:35300 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750823AbdANETr (ORCPT ); Fri, 13 Jan 2017 23:19:47 -0500 In-Reply-To: <20170113061142.127344-1-ycheng@google.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Yuchung Cheng Date: Thu, 12 Jan 2017 22:11:29 -0800 > The patch set enables RACK loss detection (draft-ietf-tcpm-rack-01) > to trigger fast recovery with a reordering timer. > > Previously RACK has been running in auxiliary mode where it is > used to detect packet losses once the recovery has triggered by > other algorithms (e.g., FACK). By inspecting packet timestamps, > RACK can start ACK-driven repairs timely. A few similar heuristics > are no longer needed and are either removed or disabled to reduce > the complexity of the Linux TCP loss recovery engine: > > 1. FACK (Forward Acknowledgement) > 2. Early Retransmit (RFC5827) > 3. thin_dupack (fast recovery on single DUPACK for thin-streams) > 4. NCR (Non-Congestion Robustness RFC4653) (RFC4653) > 5. Forward Retransmit > > After this change, Linux's loss recovery algorithms consist of > 1. Conventional DUPACK threshold approach (RFC6675) > 2. RACK and Tail Loss Probe (draft-ietf-tcpm-rack-01) > 3. RTO plus F-RTO extension (RFC5682) > > The patch set has been tested on Google servers extensively and > presented in several IETF meetings. The data suggests that RACK > successfully improves recovery performance: > https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-draft-ietf-tcpm-rack-01.pdf > https://www.ietf.org/proceedings/96/slides/slides-96-tcpm-3.pdf Series applied, thanks for all of your hard work.