From owner-freebsd-chat@FreeBSD.ORG Wed Dec 6 23:06:59 2006 Return-Path: X-Original-To: freebsd-chat@freebsd.org Delivered-To: freebsd-chat@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 908ED16A417 for ; Wed, 6 Dec 2006 23:06:59 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from server.baldwin.cx (66-23-211-162.clients.speedfactory.net [66.23.211.162]) by mx1.FreeBSD.org (Postfix) with ESMTP id 821A243D69 for ; Wed, 6 Dec 2006 23:05:57 +0000 (GMT) (envelope-from jhb@freebsd.org) Received: from localhost.corp.yahoo.com (john@localhost [127.0.0.1]) (authenticated bits=0) by server.baldwin.cx (8.13.6/8.13.6) with ESMTP id kB6N6DOT064156; Wed, 6 Dec 2006 18:06:13 -0500 (EST) (envelope-from jhb@freebsd.org) From: John Baldwin To: freebsd-chat@freebsd.org Date: Wed, 6 Dec 2006 18:05:05 -0500 User-Agent: KMail/1.9.1 References: <200612041443.15154.josh@tcbug.org> <200612061006.56852.jhb@freebsd.org> <20061206134536.0c775367@freen0de> In-Reply-To: <20061206134536.0c775367@freen0de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200612061805.05727.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [127.0.0.1]); Wed, 06 Dec 2006 18:06:13 -0500 (EST) X-Virus-Scanned: ClamAV 0.88.3/2295/Wed Dec 6 15:57:06 2006 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-4.4 required=4.2 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.1.3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on server.baldwin.cx Cc: Subject: Re: Venting my frustration with FreeBSD X-BeenThere: freebsd-chat@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Non technical items related to the community List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Dec 2006 23:06:59 -0000 On Wednesday 06 December 2006 16:45, soralx@cydem.org wrote: > > > 512-way machine? Scaling on a 512-way machine is quite a different > > ball of wax from scaling on 4-way, and scaling up to 32 and 64 is > > going to be another ball of wax as well. > > can you give a few examples how scaling ability can be a function of > the number of cores? seems like my curiosity exceeds my imagination > today -- can't come up with any good reasons why this is true :) You may make different tradeoffs. For example, on a 4-cpu system, it may be fine to have certain data structures shared across CPUs and protected via a lock which avoids the overhead of multiple copies and complexity of updating multiple copies of a data structure. However, with a 512-way system you may have to resort to using duplicated per-cpu (or maybe per-cpu group) copies of a structure because the tradeoffs are different. -- John Baldwin