From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Borkmann Subject: Re: zero copy with PACKET_MMAP Date: Thu, 27 Feb 2014 10:58:30 +0100 Message-ID: <530F0C46.5040208@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-net@vger.kernel.org To: ratheesh kannoth Return-path: Received: from mx1.redhat.com ([209.132.183.28]:37314 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751030AbaB0J6e (ORCPT ); Thu, 27 Feb 2014 04:58:34 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 02/27/2014 07:40 AM, ratheesh kannoth wrote: ... > https://www.kernel.org/doc/Documentation/networking/packet_mmap.txt > talks about achieving zero copy. But i find a deep packet copy ( of > length snaplen= skb->len ) here > http://lxr.free-electrons.com/source/net/packet/af_packet.c#L1841. > > Is there anything missing/wrong in my understanding ? The zero-copy is between user and kernel space.