From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934685Ab1JaWlp (ORCPT ); Mon, 31 Oct 2011 18:41:45 -0400 Received: from mail.solarflare.com ([216.237.3.220]:36239 "EHLO exchange.solarflare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934441Ab1JaWln (ORCPT ); Mon, 31 Oct 2011 18:41:43 -0400 Subject: Re: [PATCH] bonding:update speed/duplex for NETDEV_CHANGE From: Ben Hutchings To: Jay Vosburgh CC: Weiping Pan , , , In-Reply-To: <16441.1320096188@death> References: <4EAE0D9A.9060408@gmail.com> <1320084906.2735.9.camel@bwh-desktop> <14973.1320093129@death> <1320094108.2735.15.camel@bwh-desktop> <16441.1320096188@death> Content-Type: text/plain; charset="UTF-8" Organization: Solarflare Communications Date: Mon, 31 Oct 2011 22:41:39 +0000 Message-ID: <1320100899.2735.19.camel@bwh-desktop> MIME-Version: 1.0 X-Mailer: Evolution 2.32.2 (2.32.2-1.fc14) Content-Transfer-Encoding: 7bit X-Originating-IP: [10.17.20.137] X-TM-AS-Product-Ver: SMEX-8.0.0.1181-6.500.1024-18482.005 X-TM-AS-Result: No--27.914400-0.000000-31 X-TM-AS-User-Approved-Sender: Yes X-TM-AS-User-Blocked-Sender: No X-OriginalArrivalTime: 31 Oct 2011 22:41:43.0392 (UTC) FILETIME=[43633E00:01CC981E] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-10-31 at 14:23 -0700, Jay Vosburgh wrote: > Ben Hutchings wrote: > > >On Mon, 2011-10-31 at 13:32 -0700, Jay Vosburgh wrote: > >[...] > >> This particular case arises only during enslavement. The call > >> to bond_update_speed_duplex call has failed, but the device is marked by > >> bonding to be up. Bonding complains that the device isn't down, but it > >> cannot get speed and duplex, and therefore is assuming them to be > >> 100/Full. > >> > >> The catch is that this happens only for the ARP monitor, because > >> it initially presumes a slave to be up regardless of actual carrier > >> state (for historical reasons related to very old 10 or 10/100 drivers, > >> prior to the introduction of netif_carrier_*). > > > >Right, I gathered that. Is there any reason to use the ARP monitor when > >all slaves support link state notification? Maybe the bonding > >documentation should recommend miimon in section 7, not just in section > >2. > > The ARP monitor can validate that traffic actually flows from > the slave to some destination in the switch domain (and back), so, for > example, it's useful in cases that multiple switch hops exist between > the host and the local router. A link failure in the middle of the path > won't affect carrier on the local device, but still may cause a > communications break. Then the ARP monitor should gracefully handle the case where a new slave has link down, as proposed. Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.