From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [PATCH] af_packet: Don't use skb after dev_queue_xmit() Date: Wed, 6 Jan 2010 00:29:20 +0100 Message-ID: <20100105232920.GA8002@del.dom.local> References: <20100105230746.GA6612@del.dom.local> <4B43C86A.1090004@majjas.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Miller , shemminger@linux-foundation.org, akpm@linux-foundation.org, flyboy@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: Michael Breuer Return-path: Received: from mail-fx0-f225.google.com ([209.85.220.225]:48119 "EHLO mail-fx0-f225.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754812Ab0AEX30 (ORCPT ); Tue, 5 Jan 2010 18:29:26 -0500 Content-Disposition: inline In-Reply-To: <4B43C86A.1090004@majjas.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Jan 05, 2010 at 06:16:58PM -0500, Michael Breuer wrote: > On 1/5/2010 6:07 PM, Jarek Poplawski wrote: > >David Miller wrote, On 12/27/2009 05:11 AM: > > > >>From: David Miller > >>Date: Sat, 26 Dec 2009 19:44:18 -0800 (PST) > >> > >>>From: Stephen Hemminger > >>>Date: Sat, 26 Dec 2009 14:05:44 -0800 > >>> > >>>>Other drivers may have same problem, I really think this ought > >>>>to be done at higher level. > >>>I tend to agree with you, and I thought we had handled all > >>>cases. Let's simply make AF_PACKET linearize the link > >>>level header before sending things out to the transmit path. > >>> > >>>I can work on this if you want. > >>Actually Stephen, I took a look and I can't see how AF_PACKET > >>can create this situation. > >> > >>It always copies into the linear area of the SKB it allocates > >>for sendmsg() processing. Whether the data comes from sendmsg > >>data or the mmap() ring buffer. > >Actually, I think there is a bug in this place, but of course this > >might be unconnected. Anyway, Michael, could you try this patch? > >BTW, did you try with CONFIG_PACKET_MMAP disabled? > I did not try with CONFIG_PACKET_MMAP disabled. > > Please let me know which permutations of the following would be most > valuable to test: > Davids patch in/out > The attached patch in/out > CONFIG_PACKET_MMAP on/off > > I'm thinking your patch in, david's out, with and without > CONFIG_PACKET_MMAP. I'm not sure about David's (except do it first ;-), but try my patch with CONFIG_PACKET_MMAP on; if there is no change, CONFIG_PACKET_MMAP off, without any patches. Thanks, Jarek P.