Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752415AbcD0M3i (ORCPT ); Wed, 27 Apr 2016 08:29:38 -0400 Received: from mail-pf0-f171.google.com ([209.85.192.171]:35546 "EHLO mail-pf0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750785AbcD0M3g (ORCPT ); Wed, 27 Apr 2016 08:29:36 -0400 Subject: Re: [PATCH net-next 9/9] taskstats: use the libnl API to align nlattr on 64-bit To: nicolas.dichtel@6wind.com, netdev@vger.kernel.org References: <1461339084-3849-1-git-send-email-nicolas.dichtel@6wind.com> <1461339084-3849-10-git-send-email-nicolas.dichtel@6wind.com> <57201287.80002@gmail.com> <57206A47.2010906@6wind.com> Cc: davem@davemloft.net, linux-kernel@vger.kernel.org, linux-wpan@vger.kernel.org, aar@pengutronix.de, pablo@netfilter.org, kaber@trash.net, kadlec@blackhole.kfki.hu, pshelar@nicira.com, kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, netfilter-devel@vger.kernel.org, dev@openvswitch.org, steffen.klassert@secunet.com, herbert@gondor.apana.org.au From: Balbir Singh Message-ID: <5720B0A2.1030405@gmail.com> Date: Wed, 27 Apr 2016 22:29:22 +1000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.1 MIME-Version: 1.0 In-Reply-To: <57206A47.2010906@6wind.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 986 Lines: 34 On 27/04/16 17:29, Nicolas Dichtel wrote: > Le 27/04/2016 03:14, Balbir Singh a ?crit : >> >> >> On 23/04/16 01:31, Nicolas Dichtel wrote: >>> Goal of this patch is to use the new libnl API to align netlink attribute >>> when needed. >>> The layout of the netlink message will be a bit different after the patch, >>> because the padattr (TASKSTATS_TYPE_STATS) will be inside the nested >>> attribute instead of before it. >>> >>> Signed-off-by: Nicolas Dichtel >> >> The layout will change/break user space -- I've not tested the patch though.. > Sigh. > > I quote David: > "All userspace components using netlink should always ignore attributes > they do not recognize in dumps. > > This is one of the most basic principles of netlink" > > Do you have some pointers so I can made some tests? > Please try https://www.kernel.org/doc/Documentation/accounting/getdelays.c iotop uses it as well. My concern is ABI breakage of user space. Balbir Singh