Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753936Ab0LaRqi (ORCPT ); Fri, 31 Dec 2010 12:46:38 -0500 Received: from mail.vyatta.com ([76.74.103.46]:58851 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753803Ab0LaRqh (ORCPT ); Fri, 31 Dec 2010 12:46:37 -0500 Date: Fri, 31 Dec 2010 09:46:34 -0800 From: Stephen Hemminger To: stefani@seibold.net Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, davem@davemloft.net, netdev@vger.kernel.org Subject: Re: [PATCH] UDPCP Communication Protocol Message-ID: <20101231094634.5b96e0d1@s6510> In-Reply-To: <1293787785-3834-1-git-send-email-stefani@seibold.net> References: <1293787785-3834-1-git-send-email-stefani@seibold.net> Organization: Vyatta X-Mailer: Claws Mail 3.7.6 (GTK+ 2.22.0; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 679 Lines: 21 On Fri, 31 Dec 2010 10:29:45 +0100 stefani@seibold.net wrote: > +struct __attribute__ ((packed)) udpcphdr { > + struct udphdr udphdr; > + __be32 chksum; > + __be16 msginfo; > + u8 fragamount; > + u8 fragnum; > + __be16 msgid; > + __be16 length; > +}; Adding (unnecessary) packed attribute will make access slow on some architectures. For arch that can't do unaligned access, the compiler ends up doing byte access for each element. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/