From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH net-next] ipv6: optimize ipv6 addresses compares Date: Wed, 11 Jul 2012 06:53:36 +0200 Message-ID: <1341982416.3265.6764.camel@edumazet-glaptop> References: <1341978558.3265.6609.camel@edumazet-glaptop> <20120710.210221.559183284956265274.davem@davemloft.net> <1341979678.3265.6660.camel@edumazet-glaptop> <20120710.211304.1112522544390324120.davem@davemloft.net> <1341981861.3265.6740.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, joe@perches.com To: David Miller Return-path: Received: from mail-wg0-f44.google.com ([74.125.82.44]:47426 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751175Ab2GKExk (ORCPT ); Wed, 11 Jul 2012 00:53:40 -0400 Received: by wgbdr13 with SMTP id dr13so640667wgb.1 for ; Tue, 10 Jul 2012 21:53:39 -0700 (PDT) In-Reply-To: <1341981861.3265.6740.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 2012-07-11 at 06:44 +0200, Eric Dumazet wrote: > I dont see where in demux code we have a 64bit access ? I guess you meant the code in include/net/inet_hashtables.h ? INET_ADDR_COOKIE() loads the two 32bits into one 64bit register/var So there is no 64bit alignment in packet header itself. Then, INET_MATCH does a *(u64 *)&(inet_sk(__sk)->inet_daddr))) This happens to work because skc_daddr & skc_rcv_saddr are at the beginning of struct sock_common, and its 8bytes aligned on 64bit arches.