From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH] cpu hotplug issue Date: Thu, 21 Jul 2011 14:22:07 +0200 Message-ID: <4E2819EF.1040301@siemens.com> References: <20110720083507.GS2400@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "kvm@vger.kernel.org" To: Vasilis Liaskovitis , Gleb Natapov Return-path: Received: from david.siemens.de ([192.35.17.14]:26765 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751483Ab1GUMWS (ORCPT ); Thu, 21 Jul 2011 08:22:18 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 2011-07-21 13:06, Vasilis Liaskovitis wrote: > More precisely: To enable cpu-hotplug at each bisect stage, I apply > this patch derived from: > http://lists.gnu.org/archive/html/qemu-devel/2010-08/msg00850.html > > diff --git a/hw/qdev.c b/hw/qdev.c > index 1aa1ea0..aed48ce 100644 > --- a/hw/qdev.c > +++ b/hw/qdev.c > @@ -327,6 +327,7 @@ BusState *sysbus_get_default(void) > if (!main_system_bus) { > main_system_bus = qbus_create(&system_bus_info, NULL, > "main-system-bus"); > + main_system_bus->allow_hotplug = 1; BTW, this reminds me why "fixing" CPU hotplug won't help a lot. We finally need to _design_ the infrastructure required for CPU hotplugging and stop hacking away reasonable bits that do not fit in the current simplistic CPU interface model. The questions are: - How should the CPU-APIC-chipset topology should look like in an ideal (qdev reworked or qdev replaced with X) world should like? - How can we make useful step in that direction given the current mechanisms (e.g. a hotpluggable APIC bus created by the chipset)? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux