From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 21 May 2001 06:57:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 21 May 2001 06:57:03 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:46714 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Mon, 21 May 2001 06:57:01 -0400 Date: Mon, 21 May 2001 12:50:32 +0200 From: Andrea Arcangeli To: "David S. Miller" Cc: Andrew Morton , Ivan Kokshaysky , Richard Henderson , linux-kernel@vger.kernel.org Subject: Re: alpha iommu fixes Message-ID: <20010521125032.K30738@athlon.random> In-Reply-To: <20010520154958.E18119@athlon.random> <3B07CF20.2ABB5468@uow.edu.au> <20010520163323.G18119@athlon.random> <15112.26868.5999.368209@pizda.ninka.net> <20010521034726.G30738@athlon.random> <15112.48708.639090.348990@pizda.ninka.net> <20010521105944.H30738@athlon.random> <15112.55709.565823.676709@pizda.ninka.net> <20010521115631.I30738@athlon.random> <15112.59880.127047.315855@pizda.ninka.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <15112.59880.127047.315855@pizda.ninka.net>; from davem@redhat.com on Mon, May 21, 2001 at 03:11:52AM -0700 X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 21, 2001 at 03:11:52AM -0700, David S. Miller wrote: > I think such designs which gobble up a gig or so of DMA mappings on they maps something like 200mbyte I think. I also seen other cards doing the same kind of stuff again for the distributed computing. > to be using dual address cycles, ie. 64-bit PCI addressing. It is > the same response you would give to someone trying to obtain 3 or more > gigabytes of user address space in a process on x86, right? You might I never seen those running on 64bit boxes even if they are supposed to run there too. Here it's a little different, 32bit virtual address space limitation isn't always a showstopper for those kind of CPU intensive apps (they don't need huge caches). > respond to that person "What you really need is x86-64." for example > :-) for the 32bit virtual address space issues of course yes ;) > To me, from this perspective, the Quadrics sounds instead like a very > broken piece of hardware. And in any event, is there even a Quadrics they're not the only ones doing that, I seen others doing that kind of stuff, it's just a matter of information memory fast across a cluster, if you delegate that work to a separate engine (btw they runs a sparc32bit cpu, also guess why they aren't pci64) you can spend much more cpu cycles of the main CPU on the userspace computations. > driver for sparc64? :-) (I'm a free software old-fart, so please > excuse my immediate association between "high end" and "proprietary" > :-) :) Andrea