From owner-freebsd-hackers Tue Mar 11 12:05:41 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id MAA05687 for hackers-outgoing; Tue, 11 Mar 1997 12:05:41 -0800 (PST) Received: from mail11.digital.com (mail11.digital.com [192.208.46.10]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id MAA05669 for ; Tue, 11 Mar 1997 12:05:32 -0800 (PST) Received: from muggsy.lkg.dec.com by mail11.digital.com (8.7.5/UNX 1.5/1.0/WV) id OAA21409; Tue, 11 Mar 1997 14:53:43 -0500 (EST) Received: from whydos.lkg.dec.com by muggsy.lkg.dec.com (5.65/DEC-Ultrix/4.3) with SMTP id AA25416; Tue, 11 Mar 1997 14:53:36 -0500 Received: from localhost.lkg.dec.com (localhost.lkg.dec.com [127.0.0.1]) by whydos.lkg.dec.com (8.6.12/8.6.12) with SMTP id PAA11664; Tue, 11 Mar 1997 15:01:21 GMT Message-Id: <199703111501.PAA11664@whydos.lkg.dec.com> X-Authentication-Warning: whydos.lkg.dec.com: Host localhost.lkg.dec.com didn't use HELO protocol X-Mailer: exmh version 1.6.5 12/11/95 To: Luigi Rizzo Cc: hackers@freebsd.org Subject: Re: performance (was: 100 Mb/s cards) In-Reply-To: Your message of "Tue, 11 Mar 1997 12:12:22 +0100." <199703111112.MAA29471@labinfo.iet.unipi.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 11 Mar 1997 15:01:21 +0000 From: Matt Thomas Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk In <199703111112.MAA29471@labinfo.iet.unipi.it> , you wrote: > I just checked the data sheets of the 21140; too bad, it appears > that the 21140 can use unaligned buffers on the TRANSMIT side but > not on the receive side. As other controllers, a packet can be > split into multiple buffers though, so that a sensible (and > sufficiently general) fix would be to store the ethernet header > (12 bytes) in the first mbuf, and the body of the packet (starting > with the IP header) in the following mbuf cluster. Doesn't work. Tried it. The first buffer will have 16 bytes and you're in the same situation. -- Matt Thomas Internet: matt@3am-software.com 3am Software Foundry WWW URL: http://www.3am-software.com/bio/matt.html Westford, MA Disclaimer: I disavow all knowledge of this message