From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next-2.6] tcp: Add SNMP counter for DEFER_ACCEPT Date: Sun, 21 Mar 2010 18:32:32 -0700 (PDT) Message-ID: <20100321.183232.123981427.davem@davemloft.net> References: <1269013038.3048.58.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: eric.dumazet@gmail.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:39757 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753744Ab0CVBcJ (ORCPT ); Sun, 21 Mar 2010 21:32:09 -0400 In-Reply-To: <1269013038.3048.58.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Fri, 19 Mar 2010 16:37:18 +0100 > Its currently hard to diagnose when ACK frames are dropped because an > application set TCP_DEFER_ACCEPT on its listening socket. > > See http://bugzilla.kernel.org/show_bug.cgi?id=15507 > > This patch adds a SNMP value, named TCPDeferAcceptDrop > > netstat -s | grep TCPDeferAcceptDrop > TCPDeferAcceptDrop: 0 > > This counter is incremented every time we drop a pure ACK frame received > by a socket in SYN_RECV state because its SYNACK retrans count is lower > than defer_accept value. > > Signed-off-by: Eric Dumazet Applied, thanks Eric.