From mboxrd@z Thu Jan 1 00:00:00 1970 From: yzhu1 Subject: Re: [PATCH net-next 1/3] ipv4: Raise tcp PMTU probe mss base size Date: Fri, 13 Feb 2015 17:49:37 +0800 Message-ID: <54DDC8B1.1050307@windriver.com> References: <1423815405-32644-1-git-send-email-fan.du@intel.com> <1423815405-32644-2-git-send-email-fan.du@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Cc: , To: Fan Du , Return-path: Received: from mail1.windriver.com ([147.11.146.13]:38644 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751655AbbBMJtc (ORCPT ); Fri, 13 Feb 2015 04:49:32 -0500 In-Reply-To: <1423815405-32644-2-git-send-email-fan.du@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: backward compatible? :-D Zhu Yanjun On 02/13/2015 04:16 PM, Fan Du wrote: > 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