From owner-freebsd-net@FreeBSD.ORG Thu Feb 13 17:44:51 2014 Return-Path: <owner-freebsd-net@FreeBSD.ORG> Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 157DC5E1 for <freebsd-net@freebsd.org>; Thu, 13 Feb 2014 17:44:51 +0000 (UTC) Received: from hergotha.csail.mit.edu (wollman-1-pt.tunnel.tserv4.nyc4.ipv6.he.net [IPv6:2001:470:1f06:ccb::2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id BF45D1D32 for <freebsd-net@freebsd.org>; Thu, 13 Feb 2014 17:44:50 +0000 (UTC) Received: from hergotha.csail.mit.edu (localhost [127.0.0.1]) by hergotha.csail.mit.edu (8.14.7/8.14.7) with ESMTP id s1DHiifZ047302; Thu, 13 Feb 2014 12:44:44 -0500 (EST) (envelope-from wollman@hergotha.csail.mit.edu) Received: (from wollman@localhost) by hergotha.csail.mit.edu (8.14.7/8.14.4/Submit) id s1DHihEk047299; Thu, 13 Feb 2014 12:44:43 -0500 (EST) (envelope-from wollman) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <21245.1163.754141.154430@hergotha.csail.mit.edu> Date: Thu, 13 Feb 2014 12:44:43 -0500 From: Garrett Wollman <wollman@bimajority.org> To: John-Mark Gurney <jmg@funkthat.com> Subject: Re: Use of contiguous physical memory in cxgbe driver In-Reply-To: <20140213075651.GY34851@funkthat.com> References: <21216.22944.314697.179039@hergotha.csail.mit.edu> <201402111348.52135.jhb@freebsd.org> <CAJ-VmonCdNQPUCQwm0OhqQ3Kt_7x6-g-JwGVZQfzWTgrDYfmqw@mail.gmail.com> <201402121446.19278.jhb@freebsd.org> <21244.20212.423983.960018@hergotha.csail.mit.edu> <20140213075651.GY34851@funkthat.com> X-Mailer: VM 7.17 under 21.4 (patch 22) "Instant Classic" XEmacs Lucid X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (hergotha.csail.mit.edu [127.0.0.1]); Thu, 13 Feb 2014 12:44:44 -0500 (EST) X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED autolearn=disabled version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on hergotha.csail.mit.edu Cc: FreeBSD Net <freebsd-net@freebsd.org> X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org> List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-net>, <mailto:freebsd-net-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net/> List-Post: <mailto:freebsd-net@freebsd.org> List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help> List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>, <mailto:freebsd-net-request@freebsd.org?subject=subscribe> X-List-Received-Date: Thu, 13 Feb 2014 17:44:51 -0000 <<On Wed, 12 Feb 2014 23:56:51 -0800, John-Mark Gurney <jmg@funkthat.com> said: > Though we might want to keep a few mbufs reserved for receive now that > you mention it... We should never get to the point where we can't > allocate even one frame for receive... It's very easy to get to that state if the driver insists on getting three physically contiguous pages (which is what it takes to allocate a single 9k cluster) -GAWollman