Arch Linux

quantumphaze

Member

From: Melbourne, Australia

Registered: 2008-11-14

Posts: 175

virt-manager freeze at startup, python2 at 100%

Hello all,

Virt-manager (allows you to do KVM virtual machines) is displaying very strange behaviour. When I run virt-manager (from menu or console) it pops up an unresponsive window and its process (pyton2 /usr/share/virt-manager/virt-manager.py) it burns 100% of a CPU core. The real strangeness is that when I run it with an argument such as "--debug" or "-- no-fork" that prevents it from forking to background it runs fine as normal. It's very similar to a Redhat bug described here except that it happens immediately when the window appears.

I suspect that, since I use KDE, some odd GTK/Gnome dependency has been overlooked. Does this problem happen to anyone else? This happens on two of my systems that run Arch Linux and I want to exclude my own configuration problems before I file a bug report.

Last edited by quantumphaze (2013-04-13 12:39:13)

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quantumphaze

Member

From: Melbourne, Australia

Registered: 2008-11-14

Posts: 175

Re: virt-manager freeze at startup, python2 at 100%

Well I have narrowed the problem down to the drop_tty() function on line 85 of /usr/share/virt-manager/virt-manager.py

def drop_tty():
    # We fork and setsid so that we drop the controlling
    # tty. This prevents libvirt's SSH tunnels from prompting
    # for user input if SSH keys/agent aren't configured.
    if os.fork() != 0:
        os._exit(0)

    os.setsid()

If I comment out the part that calls drop_tty on line 348 it works fine.
Commenting out os.setsid() still freezes.
Commenting out the os.fork and os._exit part causes it to throw out "OSError: [Errno 1] Operation not permitted"
I suspect os.fork() is doing bad things. Does anyone know enough about Python to know what is actually happening?

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