From patchwork Thu Feb 26 03:49:23 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fan Du X-Patchwork-Id: 443785 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 9B57114010F for ; Thu, 26 Feb 2015 14:54:17 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753039AbbBZDyM (ORCPT ); Wed, 25 Feb 2015 22:54:12 -0500 Received: from mga02.intel.com ([134.134.136.20]:41796 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752401AbbBZDyL (ORCPT ); Wed, 25 Feb 2015 22:54:11 -0500 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP; 25 Feb 2015 19:54:08 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,650,1418112000"; d="scan'208";a="683587270" Received: from dufan-optiplex-9010.bj.intel.com ([10.238.155.116]) by fmsmga002.fm.intel.com with ESMTP; 25 Feb 2015 19:54:05 -0800 From: Fan Du To: johnwheffner@gmail.com Cc: edumazet@google.com, davem@davemloft.net, netdev@vger.kernel.org, fengyuleidian0615@gmail.com Subject: [PATCHv2 net-next 1/4] ipv4: Raise tcp PMTU probe mss base size Date: Thu, 26 Feb 2015 11:49:23 +0800 Message-Id: <1424922566-6787-2-git-send-email-fan.du@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1424922566-6787-1-git-send-email-fan.du@intel.com> References: <1423815405-32644-1-git-send-email-fan.du@intel.com> <1424922566-6787-1-git-send-email-fan.du@intel.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Quotes from RFC4821 7.2. Selecting Initial Values It is RECOMMENDED that search_low be initially set to an MTU size that is likely to work over a very wide range of environments. Given today's technologies, a value of 1024 bytes is probably safe enough. The initial value for search_low SHOULD be configurable. Moreover, set a small value will introduce extra time for the search to converge. So set the initial probe base mss size to 1024 Bytes. Signed-off-by: Fan Du --- include/net/tcp.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 8d6b983..7b57e5b 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -65,7 +65,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo); #define TCP_MIN_MSS 88U /* The least MTU to use for probing */ -#define TCP_BASE_MSS 512 +#define TCP_BASE_MSS 1024 /* After receiving this amount of duplicate ACKs fast retransmit starts. */ #define TCP_FASTRETRANS_THRESH 3