From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: xl vcpu-set crashes Dom0 Date: Mon, 28 Feb 2011 20:51:12 +0000 Message-ID: References: <4D6BDA07.2010707@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4D6BDA07.2010707@amd.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Andre Przywara Cc: Juergen Gross , xen-devel List-Id: xen-devel@lists.xenproject.org On 28/02/2011 17:23, "Andre Przywara" wrote: > Hi, > > as mentioned earlier today I had some issues with patch 22934, which > decreases the number of vCPUs for Dom0 in case of cpupool-numa-split. > I now found that this is not directly related to this patch, as it > triggers also with "xl vcpu-set". So far I tried the following combinations: > c/s 22956 on a machine with 48 physical CPUs: > not restricted dom0: > xl vcpu-set 0 6 => crashes > xl vcpu-set 0 47 => crashes > dom0_max_vcpus=6 > xl vcpu-set 0 5 => crashes > xm vcpu-set 0 5 => crashes > > The only message I get is: > root@dosorca:~# xm vcpu-set 0 5 > (XEN) Domain 0 crashed: rebooting machine in 5 seconds. Dom0 has oopsed. If you have a synchronous log of dmesg (e.g., via serial) then you should be able to get an oops message and backtrace from dom0 kernel. My first guess would be this is a bug in the kernel's handling of cpu hotplug requests via xenstore. -- Keir > Debugging turned out that for instance the libxl_set_vcpuonline() > returns without an error, but the machine then crashes afterwards. > > Can someone reproduce this? Any ideas? > > Regards, > Andre.