From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: cpu hotplug Date: Sun, 19 Sep 2010 12:46:46 +0200 Message-ID: <20100919104646.GO3008@redhat.com> References: <1284759576.9521.137.camel@frechmops.schnuffi.conrad.localdomain> <20100918143259.GA30158@morn.localdomain> <1284834474.9521.161.camel@frechmops.schnuffi.conrad.localdomain> <20100919063812.GN3008@redhat.com> <1284892897.9521.179.camel@frechmops.schnuffi.conrad.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: Conrad Wood Return-path: Received: from mx1.redhat.com ([209.132.183.28]:23113 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752411Ab0ISKqw (ORCPT ); Sun, 19 Sep 2010 06:46:52 -0400 Content-Disposition: inline In-Reply-To: <1284892897.9521.179.camel@frechmops.schnuffi.conrad.localdomain> Sender: kvm-owner@vger.kernel.org List-ID: On Sun, Sep 19, 2010 at 12:41:37PM +0200, Conrad Wood wrote: > On Sun, 2010-09-19 at 08:38 +0200, Gleb Natapov wrote: > > On Sat, Sep 18, 2010 at 08:27:54PM +0200, Conrad Wood wrote: > > > On Sat, 2010-09-18 at 10:32 -0400, Kevin O'Connor wrote: > > > > On Fri, Sep 17, 2010 at 11:39:36PM +0200, Conrad Wood wrote: > > > > > Hi everyone, > > > > > > > > > > I'm currently looking into hotplugging CPUs. > > > > > This exclusively with linux-guests and linux-host. > > > > > I have found some (conflicting) information about this on the net. > > > > > > [...] > > Well, I got a bit further - thanks so far for your help. > Given > 1. kvm-72 > 2. linux-guest-kernel 2.6.35.4 > 3. kernel cmdline "maxcpus=32 possible_cpus=32" > > I can set "cpu_set 5 online" in the monitor and get indeed a new cpu > appearing in /sys/devices..., which I can then set online in the guest > by doing echo 1 >/sys/devices/.../online. > > /proc/cpuinfo in the guest then reports the new cpu. > > But... why does the command "info cpus" in the monitor report all cpus > apart from CPU0 as (halted) ? > Because they are halted? Run multiple cpu hogs in the guest and see if cpus will still be halted as reported by monitor. Also kvm-72 is so ancient that I am not sure it reports cpu state correctly in monitor at all. -- Gleb.