From owner-freebsd-current@FreeBSD.ORG Mon Dec 17 21:32:31 2007 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E324216A41A; Mon, 17 Dec 2007 21:32:31 +0000 (UTC) (envelope-from davidch@broadcom.com) Received: from mms1.broadcom.com (mms1.broadcom.com [216.31.210.17]) by mx1.freebsd.org (Postfix) with ESMTP id B7A7713C45B; Mon, 17 Dec 2007 21:32:31 +0000 (UTC) (envelope-from davidch@broadcom.com) Received: from [10.10.64.154] by mms1.broadcom.com with ESMTP (Broadcom SMTP Relay (Email Firewall v6.3.1)); Mon, 17 Dec 2007 13:02:01 -0800 X-Server-Uuid: 6B5CFB92-F616-4477-B110-55F967A57302 Received: by mail-irva-10.broadcom.com (Postfix, from userid 47) id C4C922AF; Mon, 17 Dec 2007 13:02:01 -0800 (PST) Received: from mail-irva-8.broadcom.com (mail-irva-8 [10.10.64.221]) by mail-irva-10.broadcom.com (Postfix) with ESMTP id AF4102AE; Mon, 17 Dec 2007 13:02:01 -0800 (PST) Received: from mail-irva-12.broadcom.com (mail-irva-12.broadcom.com [10.10.64.146]) by mail-irva-8.broadcom.com (MOS 3.7.5a-GA) with ESMTP id GCN13681; Mon, 17 Dec 2007 13:02:01 -0800 (PST) Received: from NT-IRVA-0750.brcm.ad.broadcom.com ( nt-irva-0750.brcm.ad.broadcom.com [10.8.194.64]) by mail-irva-12.broadcom.com (Postfix) with ESMTP id 0C09969CA3; Mon, 17 Dec 2007 13:02:01 -0800 (PST) X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Date: Mon, 17 Dec 2007 13:01:59 -0800 Message-ID: <09BFF2FA5EAB4A45B6655E151BBDD903068DBCBF@NT-IRVA-0750.brcm.ad.broadcom.com> In-Reply-To: <4764EDD0.5050101@freebsd.org> Thread-Topic: pending changes for TOE support thread-index: Acg/xR4BZza3skhCQKCeixqNMbs0JgBKVPcA References: <20071215100351.Q70617@fledge.watson.org> <4764EDD0.5050101@freebsd.org> From: "David Christensen" To: darrenr@freebsd.org, "Kip Macy" X-WSS-ID: 6B783C435IG13960771-01-01 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Cc: FreeBSD Current , Robert Watson , freebsd-arch@freebsd.org Subject: RE: pending changes for TOE support X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 17 Dec 2007 21:32:32 -0000 > >> + * The TOE API assumes that the tcp offload engine can offload the > >> + * the entire connection from set up to teardown, with=20 > some provision > >> + * being made to allowing the software stack to handle=20 > time wait. If > >> + * the device does not meet these criteria, it is the=20 > driver's responsibility > >> + * to overload the functions that it needs to in=20 > tcp_usrreqs and make > >> + * its own calls to tcp_output if it needs to do so. > >> > >> While I'm familiar with TCP, I'm less familiar with the=20 > scope of what cards > >> support for TOE. Do we know of any cards that are less=20 > capable than the > >> chelsio card in this respect, or are they all sort of=20 > on-par on that front? > >> I.e., do we think the above eventuality is likely? > >=20 > > I don't have any way of knowing. I think it is probably safe to say > > that any vendors that don't meet that criteria now will in=20 > the future > > as transistor density increases. >=20 > There are cards (or at least I've heard talk of this) that do partial > TCP offload - that is the connection setup and teardown are handled by > the operating system and that only data transfer is offloaded. I'm in > the wrong country to chase down details on this ;( You are referring to Microsoft Chimney architecture which would be supported by all TOE adapters that operate under Windows (our=20 NetXtreme II controllers included). There are IP issues related to a chimney style implementation that would likely preclude their use under FreeBSD including passing TCP state information between the host OS and the controller among them. Dave