From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fan Du Subject: Re: [DISCUSSION] rt6i_genid Date: Fri, 19 Jul 2013 15:50:20 +0800 Message-ID: <51E8EFBC.6040902@windriver.com> References: <51E881EB.5040600@windriver.com> <20130718.201801.1591610112107900505.davem@davemloft.net> <51E8B273.1090002@windriver.com> <20130718.203100.1960741588589171145.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: , To: David Miller Return-path: Received: from mail.windriver.com ([147.11.1.11]:38720 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750770Ab3GSHtx (ORCPT ); Fri, 19 Jul 2013 03:49:53 -0400 In-Reply-To: <20130718.203100.1960741588589171145.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On 2013=E5=B9=B407=E6=9C=8819=E6=97=A5 11:31, David Miller wrote: > From: Fan Du > Date: Fri, 19 Jul 2013 11:28:51 +0800 > >> On 2013=E5=B9=B407=E6=9C=8819=E6=97=A5 11:18, David Miller wrote: >>> Although it's a correct change, it is of almost no value. %99.9999= 999 >>> of users will be running kernels with CONFIG_XFRM enabled. >> >> Thanks. Good to know %99.99999999 users protect their networking wit= h >> IPsec. > > That is not what I said. > > I said that nearly every user will be running a kernel with that > config option enabled, I did not say that they will actually be > using IPSEC. > > Distributions enable all options, so that users may use any facility > that they want. > > So optimizing for things like this are almost pointless. > I've understood the situation/point you're trying to describe. No problem, I will drop this almost-pointless patch :) The original commit is targeted for XFRM policy inserting/removing, but it uses net genid shared by both IPv4 and IPv6, the side effect is add/delete IPv4 address will invalidate IPv6 dst in all. We *do* need to bump genid when add/delete IPv6 address in scenario I described here: http://www.spinics.net/lists/netdev/msg243398.html, but definitely not from add/delete IPv4 address. Moreover test shows that DCCP still push thousands of packets on wire after delete its IPv6 address in the same scenario I describe before. The impulse to bump genid for IPv6 is much more stronger after this commit even do it unintentionally. So am I missing some thing more important inside IPv6, Dave? --=20 =E6=B5=AE=E6=B2=89=E9=9A=8F=E6=B5=AA=E5=8F=AA=E8=AE=B0=E4=BB=8A=E6=9C=9D= =E7=AC=91 --fan