On 28.06.2012 12:18, Corentin Chary wrote:
Please use "gdb -p <pid>" to attach qemu when stuck and use it to dump
a full backtrace. Note that I never tested qemu-kvm and the vnc code
was originally not written for it, so the locking stuff may be broken
if the codebase differs from upstream qemu too much.
Hi Corentin,
it seems that this issue is not caused by the threaded vnc server. The
race condition is also reproducible if the threaded vnc server is
deactivated.
Sorry for the noise.
Peter
Le 26 juin 2012 17:02, "Peter Lieven" <p...@dlhnet.de
<mailto:p...@dlhnet.de>> a écrit :
On 13.03.2012 16:06, Alexander Graf wrote:
On 13.03.2012, at 16:05, Corentin Chary wrote:
On Tue, Mar 13, 2012 at 12:29 PM, Peter Lieven<p...@dlh.net
<mailto:p...@dlh.net>> wrote:
On 11.02.2012 09:55, Corentin Chary wrote:
On Thu, Feb 9, 2012 at 7:08 PM, Peter
Lieven<p...@dlh.net <mailto:p...@dlh.net>> wrote:
Hi,
is anyone aware if there are still problems
when enabling the threaded
vnc
server?
I saw some VMs crashing when using a qemu-kvm
build with
--enable-vnc-thread.
qemu-kvm-1.0[22646]: segfault at 0 ip
00007fec1ca7ea0b sp
00007fec19d056d0
error 6 in libz.so.1.2.3.3[7fec1ca75000+16000]
qemu-kvm-1.0[26056]: segfault at 7f06d8d6e010
ip 00007f06e0a30d71 sp
00007f06df035748 error 6 in libc-2.11.1.so
<http://libc-2.11.1.so>[7f06e09aa000+17a000]
I had no time to debug further. It seems to
happen shortly after
migrating,
but thats uncertain. At least the segfault in
libz seems to
give a hint to VNC since I cannot image of any
other part of qemu-kvm
using
libz except for VNC server.
Thanks,
Peter
Hi Peter,
I found two patches on my git tree that I sent
long ago but somehow
get lost on the mailing list. I rebased the tree
but did not have the
time (yet) to test them.
http://git.iksaif.net/?p=qemu.git;a=shortlog;h=refs/heads/wip
Feel free to try them. If QEMU segfault again,
please send a full gdb
backtrace / valgrind trace / way to reproduce :).
Thanks,
I have seen no more crashes with these to patches
applied. I would suggest
it would be good to push them to the master repository.
Thank you,
Peter
Ccing Alexander,
Ah, cool. Corentin, I think you're right now the closest thing
we have to a maintainer for VNC. Could you please just send
out a pull request for those?
hi all,
i suspect there is still a problem with the threaded vnc server.
its just a guess, but we saw a resonable number of vms hanging in the
last weeks. hanging meaning the emulation is stopped and the
qemu-kvm process does no longer react, not on monitor, not on vnc,
not on qmp.
why i suspect the threaded vnc server is that in all cases we have
analyzed this happened with an open vnc session and only on nodes
with the threaded vnc server
enabled. it might also be the case that this happens at a
resolution change. is there anything known or has someone an idea?
we are running qemu-kvm 1.0.1 with
vnc: don't mess up with iohandlers in the vnc thread
vnc: Limit r/w access to size of allocated memory
compiled in.
unfortunately, i was not yet able to reproduce this with a
debugger attached.
thanks,
peter
Alex
