Re: Hangs

chris
2008-12-03T17:50:36Z

On Wed, Dec 03, 2008 at 12:44:54PM +0200, Avi Kivity wrote:
> chris@versecorp.net wrote:
> >
> >I have a way to reproduce my instance of the problem easily now. I was
> >trying
> >to build a new kernel on my guest, and found that depmod hangs guests
> >every time.
> > In my case, I only have an amd processor - I don't have an intel
> >host to try it on, right now, but it happens on Ubuntu 8.04
> >and Ubuntu 8.10 guests, both using kvm-79 and the version of kvm that ships
> >with ubuntu 8.10.
> >
>
> What's your guest, how is qemu launched (command line)?
>
> --
> error compiling committee.c: too many arguments to function
>
> --
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The guest is Ubuntu 8.10 server (64-bit version). I also have the same
problems with Ubuntu 8.04LTS server.

Here's the command line:

sudo /usr/local/bin/qemu-system-x86_64 \
-no-kvm-irqchip \
-daemonize \
-hda Imgs/sam_home.img \
-m 512 \
-cdrom ISOs/ubuntu-8.10-server-amd64.iso \
-parallel /dev/lp0 \
-vnc :1 \
-net nic,macaddr=DE:AD:BE:EF:01:01,model=e1000 \
-net tap,ifname=tap1,script=/home/chris/kvm/qemu-ifup.sh \
>>& Logs/sam_run.log

Earlier in the mail chain, Marcelo had me run vmstat when it was hung,
and it was all zeros. He also asked for a stack trace on the qemu and it
showed two threads:

(gdb) info threads
2 Thread 0x414f1950 (LWP 422) 0x00007f36f07a03e1 in sigtimedwait ()
from /lib/libc.so.6
1 Thread 0x7f36f1f306e0 (LWP 414) 0x00007f36f084b482 in select ()
from /lib/libc.so.6
(gdb) thread 1
[Switching to thread 1 (Thread 0x7f36f1f306e0 (LWP 414))]#0 0x00007f36f084b482
+in select () from /lib/libc.so.6
(gdb) bt
#0 0x00007f36f084b482 in select () from /lib/libc.so.6
#1 0x00000000004094cb in main_loop_wait (timeout=0)
at /home/chris/pkgs/kvm/kvm-79/qemu/vl.c:4719
#2 0x000000000050a7ea in kvm_main_loop ()
at /home/chris/pkgs/kvm/kvm-79/qemu/qemu-kvm.c:619
#3 0x000000000040fafc in main (argc=<value optimized out>,
argv=0x7ffff9f41948) at /home/chris/pkgs/kvm/kvm-79/qemu/vl.c:4871
(gdb) thread 2
[Switching to thread 2 (Thread 0x414f1950 (LWP 422))]#0 0x00007f36f07a03e1 in
+sigtimedwait () from /lib/libc.so.6
(gdb) bt
#0 0x00007f36f07a03e1 in sigtimedwait () from /lib/libc.so.6
#1 0x000000000050a560 in kvm_main_loop_wait (env=0xc319e0, timeout=0)
at /home/chris/pkgs/kvm/kvm-79/qemu/qemu-kvm.c:284
#2 0x000000000050aaf7 in ap_main_loop (_env=<value optimized out>)
at /home/chris/pkgs/kvm/kvm-79/qemu/qemu-kvm.c:425
#3 0x00007f36f11ba3ea in start_thread () from /lib/libpthread.so.0
#4 0x00007f36f0852c6d in clone () from /lib/libc.so.6
#5 0x0000000000000000 in ?? ()

If I can provide any other debug info I'm happy to. I'm beginning to suspect
you'll be able to easily reproduce it if you run Ubuntu 8.10 as a guest on
amd processors.