From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262802AbTJJO11 (ORCPT ); Fri, 10 Oct 2003 10:27:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262640AbTJJO11 (ORCPT ); Fri, 10 Oct 2003 10:27:27 -0400 Received: from mail3.ithnet.com ([217.64.64.7]:24270 "HELO heather-ng.ithnet.com") by vger.kernel.org with SMTP id S262802AbTJJO1Y (ORCPT ); Fri, 10 Oct 2003 10:27:24 -0400 X-Sender-Authentication: net64 Date: Fri, 10 Oct 2003 16:27:22 +0200 From: Stephan von Krawczynski To: Stuart Longland Cc: lgb@lgb.hu, Fabian.Frederick@prov-liege.be, linux-kernel@vger.kernel.org Subject: Re: 2.7 thoughts Message-Id: <20031010162722.3cd1813f.skraw@ithnet.com> In-Reply-To: <3F86BD0E.4060607@longlandclan.hopto.org> References: <20031009115809.GE8370@vega.digitel2002.hu> <20031009165723.43ae9cb5.skraw@ithnet.com> <3F864F82.4050509@longlandclan.hopto.org> <20031010125137.4080a13b.skraw@ithnet.com> <3F86BD0E.4060607@longlandclan.hopto.org> Organization: ith Kommunikationstechnik GmbH X-Mailer: Sylpheed version 0.9.6 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 11 Oct 2003 00:07:10 +1000 Stuart Longland wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Stephan von Krawczynski wrote: > > > You are obviously not quite familiar with industrial boxes where this is > > state-of-the-art. > > > > [...] > > > > Generally spoken every part of a computer should be thought of as a > > "resource" that can be added or removed at any time during runtime. CPU or > > RAM is in no way different. > > Hotplug RAM I could see would be possible, but hotplug CPUs? I spose if > you've got a multiprocessor box, you could swap them one at a time, but > my thinking is that this would cause issues with the OS as it wouldn't > be expecting the CPU to suddenly disappear. Problems would be even > worse if the old and new CPUs were of different types too. I wouldn't expect a hotplug feature for differing CPU types actually. But in fact there are boxes out there that complain via phonecall that a processor board just died and request replacement. Same goes for RAM. It is obvious that no feature like this exists on desktop nowadays, but 2.7 and release of 2.8 is far ahead, so I see no good reason why people should not be enabled to do this - _then_ . In fact it is sounds really simple to plug in additional boards to a numa-type box. Boards meaning RAM+CPU. HP builds hotplug PCI stuff in comparably cheap boxes, so this is not completely off-reality. > Hotplug RAM would also be interesting, but then again, I spose the > procedure would be to alert the kernel that the memory area from byte X > to byte Y would disappear, so it could page that out to swapspace. This direction sounds likely. Regards, Stephan