Comment 7 for bug 707313

I think the poll is a red herring...the new version of virt-manager actually does have a 1000ms timeout when I strace it.

So, oddly the issue doesn't pop up with virt-manager --debug...and looking though the code, when --debug is not used, it calls this:

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()

As soon as it forks, CPU goes up to 100%.