From owner-cvs-all@FreeBSD.ORG Wed Apr 26 06:30:05 2006 Return-Path: X-Original-To: cvs-all@FreeBSD.org Delivered-To: cvs-all@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id AA65A16A402; Wed, 26 Apr 2006 06:30:05 +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 21B7343D4C; Wed, 26 Apr 2006 06:30:05 +0000 (GMT) (envelope-from mj@feral.com) Received: from ns1.feral.com (localhost [127.0.0.1]) by ns1.feral.com (8.13.6/8.13.6) with ESMTP id k3Q6U16b067889; Tue, 25 Apr 2006 23:30:01 -0700 (PDT) (envelope-from mj@feral.com) Received: from localhost (mjacob@localhost) by ns1.feral.com (8.13.6/8.13.4/Submit) with ESMTP id k3Q6U1cC067886; Tue, 25 Apr 2006 23:30:01 -0700 (PDT) (envelope-from mj@feral.com) X-Authentication-Warning: ns1.feral.com: mjacob owned process doing -bs Date: Tue, 25 Apr 2006 23:30:01 -0700 (PDT) From: Matthew Jacob X-X-Sender: mjacob@ns1.feral.com To: Scott Long In-Reply-To: <444F1216.5070303@samsco.org> Message-ID: <20060425232507.Q67867@ns1.feral.com> References: <444E7750.206@samsco.org> <200604251540.00170.jhb@freebsd.org> <444E7BFE.4040800@samsco.org> <20060425.173236.74726638.imp@bsdimp.com> <444EB6A1.3060901@samsco.org> <20060426103623.M1847@epsplex.bde.org> <20060425223519.F65802@ns1.feral.com> <444F0923.8050508@samsco.org> <20060425224750.K65869@ns1.feral.com> <444F0D58.9020000@samsco.org> <20060425230508.X66143@ns1.feral.com> <444F1216.5070303@samsco.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: src-committers@FreeBSD.org, jhb@FreeBSD.org, Bruce Evans , cvs-src@FreeBSD.org, cvs-all@FreeBSD.org, Matthew Jacob , Warner Losh Subject: Re: cvs commit: src/sys/dev/bce if_bcereg.h X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Matthew Jacob List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Apr 2006 06:30:06 -0000 > Oh, I'm sure that you could contrive a silly device today to prove your > point. But really, what are you going to do other than DMA completely > randomly-associated memory pages that just happen to neighbor each > other? It's not like the kernel or any user process can own more than > 4GB of memory on i386+PAE. There are a whole class of systems which are data movement engines that have buttloads of RAM that needs to be moved in and out. The processor doesn't touch hardly any of it. Most of the hoopla about VM and fast processors are just *in the way* of moving this data at 200MB/s+ speeds. The only reason such systems are in fact i386/amd64 is that you can build them out of COTS- otherwise you might as well do a Sandpoint based system for the cost. Anyway- we're all pretty much in agreement that for now a bus_size_t on i386 need not be > 32 bits. I was just observing that IMO, such as it is, this is a pretty rapidly changing area that in a shorter time frame than you envisioned might change.