From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264409AbTICTzO (ORCPT ); Wed, 3 Sep 2003 15:55:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264234AbTICThp (ORCPT ); Wed, 3 Sep 2003 15:37:45 -0400 Received: from holomorphy.com ([66.224.33.161]:18314 "EHLO holomorphy") by vger.kernel.org with ESMTP id S264116AbTICTfj (ORCPT ); Wed, 3 Sep 2003 15:35:39 -0400 Date: Wed, 3 Sep 2003 12:36:10 -0700 From: William Lee Irwin III To: Steven Cole Cc: Larry McVoy , "Brown, Len" , Giuliano Pochini , Larry McVoy , linux-kernel@vger.kernel.org, karim@opersys.com Subject: Re: Scaling noise Message-ID: <20030903193610.GV4306@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Steven Cole , Larry McVoy , "Brown, Len" , Giuliano Pochini , Larry McVoy , linux-kernel@vger.kernel.org, karim@opersys.com References: <20030903111934.GF10257@work.bitmover.com> <20030903180037.GP4306@holomorphy.com> <1062616315.1816.22.camel@spc9.esa.lanl.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1062616315.1816.22.camel@spc9.esa.lanl.gov> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2003-09-03 at 12:00, William Lee Irwin III wrote: >> So as best as I can tell the proposal consists of using an orders-of- >> magnitude slower communication method to implement an underspecified >> solution to some research problem that to all appearances will be more >> expensive to maintain and keep running than the now extant designs. On Wed, Sep 03, 2003 at 01:11:55PM -0600, Steven Cole wrote: > You and Larry are either talking past each other, or perhaps it is I who > don't understand the not-yet-existing CC-clusters. My understanding is > that communication between nodes of a CC-cluster would be through a > shared-memory mechanism, not through much slower I/O such as a network > (even a very fast network). > From Karim Yaghmour's paper here: > http://www.opersys.com/adeos/practical-smp-clusters/ > "That being said, clustering packages may make assumptions that do not > hold in the current architecture. Primarily, by having nodes so close > together, physical network latencies and problems disappear." The communication latencies will get better that way, sure. On Wed, Sep 03, 2003 at 01:11:55PM -0600, Steven Cole wrote: >> I like distributed systems and clusters, and they're great to use for >> what they're good for. They're not substitutes in any way for tightly >> coupled systems, nor do they render large specimens thereof unnecessary. On Wed, Sep 03, 2003 at 01:11:55PM -0600, Steven Cole wrote: > My point is this: Currently at least one vendor (SGI) wants to scale the > kernel to 128 CPUs. As far as I know, the SGI Altix systems can be > configured up to 512 CPUs. If the Intel Tanglewood really will have 16 > cores per chip, very much larger systems will be possible. Will you be > able to scale the kernel to 2048 CPUs and beyond? This may happen > during the lifetime of 2.8.x, so planning should be happening either now > or soon. This is not particularly exciting (or truthfully remotely interesting) news. google for "BBN Butterfly" to see what was around ca. 1988. -- wli