From owner-freebsd-arch@FreeBSD.ORG Fri Oct 28 22:32:50 2011 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 34C031065670 for ; Fri, 28 Oct 2011 22:32:50 +0000 (UTC) (envelope-from mj@feral.com) Received: from ns1.feral.com (ns1.feral.com [192.67.166.1]) by mx1.freebsd.org (Postfix) with ESMTP id EE2168FC1F for ; Fri, 28 Oct 2011 22:32:49 +0000 (UTC) Received: from [172.16.135.105] (lportal.in1.lcl [172.16.1.9]) (authenticated bits=0) by ns1.feral.com (8.14.4/8.14.4) with ESMTP id p9SMWnSa043451 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO) for ; Fri, 28 Oct 2011 15:32:49 -0700 (PDT) (envelope-from mj@feral.com) Message-ID: <4EAB2D8C.1060405@feral.com> Date: Fri, 28 Oct 2011 15:32:44 -0700 From: Matthew Jacob Organization: Feral Software User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20110929 Thunderbird/7.0.1 MIME-Version: 1.0 To: freebsd-arch@freebsd.org References: <20111028073710.GP25601@funkthat.com> <34E9F112-930C-4836-9949-FA8A01763969@bsdimp.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (ns1.feral.com [192.67.166.1]); Fri, 28 Oct 2011 15:32:49 -0700 (PDT) Subject: Re: newbus IO ordering semantics - moving forward X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: mj@feral.com List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Oct 2011 22:32:50 -0000 On 10/28/2011 2:08 PM, Adrian Chadd wrote: > This is the offending code. Ah, I had it wrong - lots of writes, > followed by a read: > > Few architectures follow the Sparc Comet axioms (a read of I/O space forces a flush).