From patchwork Wed Sep 22 21:33:14 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Christoph Lameter (Ampere)" X-Patchwork-Id: 65457 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 84353B70DA for ; Thu, 23 Sep 2010 07:33:23 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752785Ab0IVVdT (ORCPT ); Wed, 22 Sep 2010 17:33:19 -0400 Received: from smtp106.prem.mail.ac4.yahoo.com ([76.13.13.45]:25318 "HELO smtp106.prem.mail.ac4.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751818Ab0IVVdS (ORCPT ); Wed, 22 Sep 2010 17:33:18 -0400 Received: (qmail 72965 invoked from network); 22 Sep 2010 21:33:16 -0000 Received: from router.home (cl@99.30.10.212 with plain) by smtp106.prem.mail.ac4.yahoo.com with SMTP; 22 Sep 2010 14:33:16 -0700 PDT X-Yahoo-SMTP: _Dag8S.swBC1p4FJKLCXbs8NQzyse1SYSgnAbY0- X-YMail-OSG: HpWgfoUVM1kemmvRsyegAic8HCf0vqJbT4iqKqjDgwzPcwf 65kYMdqQYSKfjvcz4.Jag8n3A37hUaL.QQa34WPqooSFFwXG6hdpPEXmqI31 HNFaFhObklEfij0ibVTxAJvYw1Ir8maVYs3hYjXKvwhJlIzRA.MPl7fmCOsy vailLlaMVPdck2.mb1be33ZY2nrXZ6KB_nZeR0HoZvbOuaOdxeoOVBUyfR5S Ed98nt_HjFZ8lB5FWPmhmqitXWNK3Bm0cfIhg_nBPC8O.tdWY97EscV6V3rN nlw-- X-Yahoo-Newman-Property: ymail-3 Received: from cl (helo=localhost) by router.home with local-esmtp (Exim 4.71) (envelope-from ) id 1OyWwF-0002Nt-Fy; Wed, 22 Sep 2010 16:33:15 -0500 Date: Wed, 22 Sep 2010 16:33:14 -0500 (CDT) From: Christoph Lameter X-X-Sender: cl@router.home To: Bob Arendt cc: David Stevens , "David S. Miller" , "linux-rdma@vger.kernel.org" , "netdev@vger.kernel.org" Subject: Re: igmp: Staggered igmp report intervals for unsolicited igmp reports In-Reply-To: <4C9A6D87.2000103@rincon.com> Message-ID: References: <4C9A6D87.2000103@rincon.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 22 Sep 2010, Bob Arendt wrote: > multicast traffic is received. While IGMPv2 defines an "Unsolicited Report > Interval" default of 10 seconds, it appears that this is a significant enough > issue that the later IGMPv3 document calls out a default of 1 second, and > goes on to define a "Robustness Variable" and talks about the same case that > Christoph is trying to mitigate. Actually that suggests a different way to reach the same goal: Subject: igmp: Make unsolicited report interval conform to RFC3376 RFC3376 specifies a shorter time interval for sending igmp joins. This can address issues where joins are slow because the initial join is frequently lost. Also increment the frequency so that we get a 10 reports send over a few seconds. Signed-off-by: Christoph Lameter --- net/ipv4/igmp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: linux-2.6/net/ipv4/igmp.c =================================================================== --- linux-2.6.orig/net/ipv4/igmp.c 2010-09-22 16:28:17.000000000 -0500 +++ linux-2.6/net/ipv4/igmp.c 2010-09-22 16:28:54.000000000 -0500 @@ -114,9 +114,9 @@ #define IGMP_V1_Router_Present_Timeout (400*HZ) #define IGMP_V2_Router_Present_Timeout (400*HZ) -#define IGMP_Unsolicited_Report_Interval (10*HZ) +#define IGMP_Unsolicited_Report_Interval (HZ) #define IGMP_Query_Response_Interval (10*HZ) -#define IGMP_Unsolicited_Report_Count 2 +#define IGMP_Unsolicited_Report_Count 10 #define IGMP_Initial_Report_Delay (1)