Hi Ben, On Sat, Dec 27, 2014 at 02:39:06AM +0100, Ben Hutchings wrote: > 1, Enable an emulated serial port for the VM, with output going to a > file.
I modified the VM to have: <serial type='file'> <source path='/var/tmp/vm1-serial.log'/> <target port='0'/> </serial> <console type='file'> <source path='/var/tmp/vm1-serial.log'/> <target type='serial' port='0'/> </console> > 2. Enable a serial console on the kernel command line. I added this to the end of the kernel boot line in the guest's /boot/grub/grub.cfg: serial console=ttyS00,115200 > 3. Set sysctl kernel.printk=7 (i.e. send all non-debug logging to the > console). I set this in the guest's /etc/sysctl.cfg > 4. Do whatever you have to do, to reproduce the hang. All that is necessary is to say "virsh start vm1". I am confused because the output is really not that much more verbose than the screnshots, but here you are: [ 22.224014] INFO: rcu_sched self-detected stall on CPU { 1} (t=5251 jiffies g=-153 c=-154 q=307) [ 22.232010] INFO: rcu_sched detected stalls on CPUs/tasks: { 1} (detected by 0, t=5252 jiffies, g=-153, c=-154, q=307) [ 22.232010] CPU: 0 PID: 122 Comm: systemd-udevd Not tainted 3.16.0-0.bpo.4-686-pae #1 Debian 3.16.7-ckt2-1~bpo70+1 [ 22.232010] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 22.232010] task: f6c96560 ti: f6cd6000 task.ti: f6cd6000 [ 22.232010] Stack: [ 22.232010] Call Trace: [ 22.232010] Code: 00 d3 ff ff 80 e5 10 75 ee c1 e3 18 89 98 10 d3 ff ff 89 f0 09 d0 80 ce 04 83 fe 02 0f 44 c2 8b 15 c4 8c 61 c1 89 82 00 d3 ff ff <89> f8 50 9d 8d 74 26 00 8b 5d f4 8b 75 f8 8b 7d fc 89 ec 5d c3 [ 22.224014] CPU: 1 PID: 129 Comm: modprobe Not tainted 3.16.0-0.bpo.4-686-pae #1 Debian 3.16.7-ckt2-1~bpo70+1 [ 22.224014] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 22.224014] task: f6d23ab0 ti: f6d44000 task.ti: f6d44000 [ 22.224014] Stack: [ 22.224014] Call Trace: [ 22.224014] Code: d3 e2 03 50 04 ec 0f b6 c0 5d c3 89 f6 8d bc 27 00 00 00 00 55 89 e5 53 3e 8d 74 26 00 89 cb 0f b6 48 35 d3 e2 03 50 04 89 d8 ee <5b> 5d c3 8d b6 00 00 00 00 55 89 e5 3e 8d 74 26 00 0f b6 50 36 [ 22.224014] CPU: 1 PID: 129 Comm: modprobe Not tainted 3.16.0-0.bpo.4-686-pae #1 Debian 3.16.7-ckt2-1~bpo70+1 [ 22.224014] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 22.224014] task: f6d23ab0 ti: f6d44000 task.ti: f6d44000 [ 22.224014] Stack: [ 22.224014] Call Trace: [ 22.224014] Code: 00 d3 ff ff 80 e5 10 75 ee c1 e3 18 89 98 10 d3 ff ff 89 f0 09 d0 80 ce 04 83 fe 02 0f 44 c2 8b 15 c4 8c 61 c1 89 82 00 d3 ff ff <89> f8 50 9d 8d 74 26 00 8b 5d f4 8b 75 f8 8b 7d fc 89 ec 5d c3 [ 22.332011] CPU: 0 PID: 122 Comm: systemd-udevd Not tainted 3.16.0-0.bpo.4-686-pae #1 Debian 3.16.7-ckt2-1~bpo70+1 [ 22.332011] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 22.332011] task: f6c96560 ti: f6cd6000 task.ti: f6cd6000 [ 22.332011] Stack: [ 22.332011] Call Trace: [ 22.332011] Code: 5d e9 38 a0 c0 ff 90 8d b4 26 00 00 00 00 55 89 e5 3e 8d 74 26 00 ba 00 01 00 00 f0 66 0f c1 10 0f b6 ce 38 d1 75 04 5d c3 f3 90 <0f> b6 10 38 ca 75 f7 5d c3 8d 76 00 8d bc 27 00 00 00 00 55 89 [ 48.032012] BUG: soft lockup - CPU#0 stuck for 22s! [systemd-udevd:122] [ 48.032012] CPU: 0 PID: 122 Comm: systemd-udevd Not tainted 3.16.0-0.bpo.4-686-pae #1 Debian 3.16.7-ckt2-1~bpo70+1 [ 48.032012] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 48.036010] BUG: soft lockup - CPU#1 stuck for 22s! [modprobe:129] [ 48.036010] CPU: 1 PID: 129 Comm: modprobe Not tainted 3.16.0-0.bpo.4-686-pae #1 Debian 3.16.7-ckt2-1~bpo70+1 [ 48.036010] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 48.036010] task: f6d23ab0 ti: f6d44000 task.ti: f6d44000 [ 48.036010] Stack: [ 48.036010] Call Trace: [ 48.036010] Code: 00 00 8d bf 00 00 00 00 89 48 04 89 10 c3 8d 76 00 8d bc 27 00 00 00 00 83 ec 08 89 74 24 04 89 c6 89 1c 24 89 d3 8b 00 8b 56 04 <f0> 0f c7 0e 75 fa 8b 1c 24 8b 74 24 04 83 c4 08 c3 8d b6 00 00 [ 48.032012] task: f6c96560 ti: f6cd6000 task.ti: f6cd6000 [ 48.032012] Stack: [ 48.032012] Call Trace: [ 48.032012] Code: 5d e9 38 a0 c0 ff 90 8d b4 26 00 00 00 00 55 89 e5 3e 8d 74 26 00 ba 00 01 00 00 f0 66 0f c1 10 0f b6 ce 38 d1 75 04 5d c3 f3 90 <0f> b6 10 38 ca 75 f7 5d c3 8d 76 00 8d bc 27 00 00 00 00 55 89 At this point, I shut the VM down because it did not seem to produce any more useful information. Kind regards, --Toni++ -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/20141227112034.ga11...@lappi1.office.oeko.net