From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:60027) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SmMRL-0003Md-75 for qemu-devel@nongnu.org; Wed, 04 Jul 2012 06:04:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SmMRE-0004Y3-TU for qemu-devel@nongnu.org; Wed, 04 Jul 2012 06:04:06 -0400 Received: from ssl.dlhnet.de ([91.198.192.8]:44417 helo=ssl.dlh.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SmMRE-0004So-NC for qemu-devel@nongnu.org; Wed, 04 Jul 2012 06:04:00 -0400 Message-ID: <4FF4150E.2030201@dlhnet.de> Date: Wed, 04 Jul 2012 12:03:58 +0200 From: Peter Lieven MIME-Version: 1.0 References: <4FEAE1EA.3070107@dlh.net> <20120703155430.GA21571@amt.cnet> In-Reply-To: <20120703155430.GA21571@amt.cnet> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] race condition in qemu-kvm-1.0.1 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Marcelo Tosatti Cc: Peter Lieven , qemu-devel@nongnu.org, kvm@vger.kernel.org On 07/03/12 17:54, Marcelo Tosatti wrote: > On Wed, Jun 27, 2012 at 12:35:22PM +0200, Peter Lieven wrote: >> Hi, >> >> we recently came across multiple VMs racing and stopping working. It >> seems to happen when the system is at 100% cpu. >> One way to reproduce this is: >> qemu-kvm-1.0.1 with vnc-thread enabled >> >> cmdline (or similar): >> /usr/bin/qemu-kvm-1.0.1 -net >> tap,vlan=141,script=no,downscript=no,ifname=tap15,vnet_hdr -net >> nic,vlan=141,model=virtio,macaddr=52:54:00:ff:00:f7 -drive format=host_device,file=/dev/mapper/iqn.2001-05.com.equallogic:0-8a0906-efdf4e007-16700198c7f4fead-02-debug-race-hd01,if=virtio,cache=none,aio=native >> -m 2048 -smp 2,sockets=1,cores=2,threads=1 -monitor >> tcp:0:4026,server,nowait -vnc :26 -qmp tcp:0:3026,server,nowait >> -name 02-debug-race -boot order=dc,menu=off -cdrom >> /home/kvm/cdrom//root/ubuntu-12.04-server-amd64.iso -k de -pidfile >> /var/run/qemu/vm-221.pid -mem-prealloc -cpu >> host,+x2apic,model_id=Intel(R) Xeon(R) CPU L5640 @ >> 2.27GHz,-tsc -rtc base=utc -usb -usbdevice tablet -no-hpet -vga >> cirrus > Is it reproducible without vnc thread enabled? Yes, it is. I tried it with and without. It is also even happnig with 0.12.5 where no vnc thread (and i think also iothread) is available. Thanks, Peter