From owner-freebsd-stable@FreeBSD.ORG Tue Nov 7 16:59:53 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 84C3216A403; Tue, 7 Nov 2006 16:59:53 +0000 (UTC) (envelope-from rrs@cisco.com) Received: from rtp-iport-2.cisco.com (rtp-iport-2.cisco.com [64.102.122.149]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2ED2A43D45; Tue, 7 Nov 2006 16:59:52 +0000 (GMT) (envelope-from rrs@cisco.com) Received: from sj-dkim-3.cisco.com ([171.71.179.195]) by rtp-iport-2.cisco.com with ESMTP; 07 Nov 2006 11:59:51 -0500 X-IronPort-AV: i="4.09,397,1157342400"; d="scan'208"; a="109013701:sNHT53981928" Received: from sj-core-5.cisco.com (sj-core-5.cisco.com [171.71.177.238]) by sj-dkim-3.cisco.com (8.12.11.20060308/8.12.11) with ESMTP id kA7Gxo1Y013076; Tue, 7 Nov 2006 08:59:50 -0800 Received: from xbh-sjc-231.amer.cisco.com (xbh-sjc-231.cisco.com [128.107.191.100]) by sj-core-5.cisco.com (8.12.10/8.12.6) with ESMTP id kA7GxoW4028904; Tue, 7 Nov 2006 08:59:50 -0800 (PST) Received: from xfe-sjc-212.amer.cisco.com ([171.70.151.187]) by xbh-sjc-231.amer.cisco.com with Microsoft SMTPSVC(6.0.3790.1830); Tue, 7 Nov 2006 08:59:50 -0800 Received: from [127.0.0.1] ([171.68.225.134]) by xfe-sjc-212.amer.cisco.com with Microsoft SMTPSVC(6.0.3790.1830); Tue, 7 Nov 2006 08:59:50 -0800 Message-ID: <4550BB5F.3040101@cisco.com> Date: Tue, 07 Nov 2006 11:59:11 -0500 From: Randall Stewart User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20050920 X-Accept-Language: en-us, en MIME-Version: 1.0 To: sivakumar.subramani@wipro.com References: <821C7AD2A9F78942B86059792262577315B072@blr-m3-msg.wipro.com> In-Reply-To: <821C7AD2A9F78942B86059792262577315B072@blr-m3-msg.wipro.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 07 Nov 2006 16:59:50.0447 (UTC) FILETIME=[2350FBF0:01C7028E] DKIM-Signature: a=rsa-sha1; q=dns; l=1055; t=1162918790; x=1163782790; c=relaxed/simple; s=sjdkim3002; h=Content-Type:From:Subject:Content-Transfer-Encoding:MIME-Version; d=cisco.com; i=rrs@cisco.com; z=From:Randall=20Stewart=20 |Subject:Re=3A=20Regarding=20Jumbo=20frame=20implementation=20in=20bge; X=v=3Dcisco.com=3B=20h=3DNUeMyZUQSQYJ+TclegbSlkBq1hc=3D; b=TmJcSIIr+qLlQKdTXzL+yewBysPQPunH041FXNRjARGjLx6kdDH5th7aG++OiM1frxK98YXK lOA0gkuCHU/QX+1DlFqnsJaHy2maknh6dPiLIRrZHhpVkKRV7ZqL/4ES; Authentication-Results: sj-dkim-3.cisco.com; header.From=rrs@cisco.com; dkim=pass ( sig from cisco.com verified; ); Cc: freebsd-net@freebsd.org, freebsd-stable@freebsd.org Subject: Re: Regarding Jumbo frame implementation in bge X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 07 Nov 2006 16:59:53 -0000 sivakumar.subramani@wipro.com wrote: > Hi, > > In bge driver, we have BGE_JUMBO_FRAMELEN defined to 9018. > if_bgereg.h:#define BGE_JUMBO_FRAMELEN 9018 > > This macro is used to allocate the memory for jumbo buffer. If I have > a MTU size of 2000, still bge will allocate the jumbo buffer of size > BGE_JUMBO_FRAMELEN. Instead can we make the size to be depend on the > MTU. I mean instead of using BGE_JUMBO_FRAMELEN macro we can use MTU > + IP header + CRC for Jumbo buffer size. > > Any reason for allocating a hard coded 9018 size all Jumbo MTU frame > (whether it is 9000 / 2000)? > > Thanks, ~Siva > Sivakumar: Allocations are done via the zone managers.. and thus setup at kernel boot. A value like the MTU is set dynamically... So doing something like this would be questionable IMO.. I am sure it could be done.. but I don't see the value. In theory you have a waste for just a short time.. before its m_free'd R -- Randall Stewart NSSTG - Cisco Systems Inc. 803-345-0369 803-317-4952 (cell)