From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753262AbcEDMxA (ORCPT ); Wed, 4 May 2016 08:53:00 -0400 Received: from zimbra13.linbit.com ([212.69.166.240]:51776 "EHLO zimbra13.linbit.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753039AbcEDMw6 convert rfc822-to-8bit (ORCPT ); Wed, 4 May 2016 08:52:58 -0400 Date: Wed, 4 May 2016 14:52:53 +0200 From: Lars Ellenberg To: Nicolas Dichtel Cc: David Miller , netdev@vger.kernel.org, philipp.reisner@linbit.com, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org Subject: Re: [Drbd-dev] [PATCH net-next v2] block/drbd: use nla_put_u64_64bit() Message-ID: <20160504125253.GP16459@soda.linbit> Mail-Followup-To: Nicolas Dichtel , David Miller , netdev@vger.kernel.org, philipp.reisner@linbit.com, drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org References: <57286F49.8050107@6wind.com> <1462268358-19044-1-git-send-email-nicolas.dichtel@6wind.com> <20160503100644.GE16459@soda.linbit> <20160503.120556.1317913903199470646.davem@davemloft.net> <20160504090529.GJ16459@soda.linbit> <5729EFBC.7040002@6wind.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <5729EFBC.7040002@6wind.com> User-Agent: Mutt/1.5.21 (2010-09-15) Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 04, 2016 at 02:49:00PM +0200, Nicolas Dichtel wrote: > Le 04/05/2016 11:05, Lars Ellenberg a écrit : > [snip] > > We don't have an "alignment problem" there, btw. > > Last time I checked, we did work fine without this alignment magic, > > we already take care of that, yes, even on affected architectures. > The code adds several consecutive u64 attributes. The nl attribute header is 4 > bytes, thus the full attribute length is 12 bytes. If the first u64 is aligned > on 8 (nla_data()), the next one is not aligned on 8: it starts 12 bytes (8 (u64) > + 4 (nl attr hdr)) after the previous u64. Yes. Which in our case is not a problem. But I don't object to the padding per se, if that is how things "should be". I try to understand why you so much object to using 0 as pad. Lars