From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowmini Varadhan Subject: Re: [PATCH net] net: Allow flow dissector to handle non 4-byte aligned headers Date: Mon, 1 Feb 2016 11:01:30 -0500 Message-ID: <20160201160130.GA22816@oracle.com> References: <1454276221-3543907-1-git-send-email-tom@herbertland.com> <1454286240.7627.160.camel@edumazet-glaptop2.roam.corp.google.com> <56AEA947.409@gmail.com> <56AF77C3.2010406@6wind.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Florian Fainelli , Eric Dumazet , Tom Herbert , davem@davemloft.net, netdev@vger.kernel.org, kernel-team@fb.com To: Nicolas Dichtel Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:32619 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751687AbcBAQBl (ORCPT ); Mon, 1 Feb 2016 11:01:41 -0500 Content-Disposition: inline In-Reply-To: <56AF77C3.2010406@6wind.com> Sender: netdev-owner@vger.kernel.org List-ID: On (02/01/16 16:20), Nicolas Dichtel wrote: > There is also the tile architecture, up to 76 cores on the board I've seen. It > requires an alignment on 8! > I wonder how this case may be properly handled. A simple ipip scenario fails. Yes, I'm also observing the same thing. Simply setting up gretap like this results in # ip link add gretap2 type gretap local myaddr remote hisaddr # ifconfig gretap2 up Kernel unaligned access at TPC[969d88] iptunnel_xmit+0xa4/0x1c0 Kernel unaligned access at TPC[969db0] iptunnel_xmit+0xcc/0x1c0 Kernel unaligned access at TPC[969dc4] iptunnel_xmit+0xe0/0x1c0 Kernel unaligned access at TPC[969dc8] iptunnel_xmit+0xe4/0x1c0 Kernel unaligned access at TPC[9191fc] __ip_select_ident+0x80/0x13c and afacit, the unaligned ip header is triggered by an inner ipv6 packet that is usually coming from mld or dad. (and fwiw, the basic iperf/ipv6 test is fine with Tom's patch, need to try out some of the other permutations without rps etc)