From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David S. Miller" Subject: Re: [PATCH 1/3] Rough VJ Channel Implementation - vj_core.patch Date: Fri, 28 Apr 2006 12:14:45 -0700 (PDT) Message-ID: <20060428.121445.81971612.davem@davemloft.net> References: <54AD0F12E08D1541B826BE97C98F99F143B0F3@NT-SJCA-0751.brcm.ad.broadcom.com> <20060428172536.GA16916@2ka.mipt.ru> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: caitlinb@broadcom.com, kelly@au1.ibm.com, rusty@rustcorp.com.au, netdev@vger.kernel.org Return-path: Received: from dsl027-180-168.sfo1.dsl.speakeasy.net ([216.27.180.168]:63683 "EHLO sunset.davemloft.net") by vger.kernel.org with ESMTP id S1751443AbWD1TQE (ORCPT ); Fri, 28 Apr 2006 15:16:04 -0400 To: johnpol@2ka.mipt.ru In-Reply-To: <20060428172536.GA16916@2ka.mipt.ru> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Evgeniy Polyakov Date: Fri, 28 Apr 2006 21:25:36 +0400 > The more complex userspace interface we create the less users it will > have. It is completely unconvenient to read 100 bytes and receive only > 80, since 20 were eaten by header. These bytes are charged to socket anyways, and allowing the headers to be there is the only clean way to finesse the whole zero-copy problem. User can manage his data any way he likes. He can decide to take advantage of the zero-copy layout we've provided, or he can copy to put things into a format he is more happy with at the cost of the copy.