My kilo setup is performing correctly. I am just trying to collect some callstack regarding OVS bridge/port/flow operations. I am able to collect all of them except the callstack when tap interface is added to br-int on the compute node. Somehow I couldn't get that callstack. Here's the change I made:

class OvsdbVsctl(ovsdb.API):
    def add_br(self, name, may_exist=True):
        opts = ['--may-exist'] if may_exist else None
        f = open('/usr/lib/python2.7/dist-packages/neutron/agent/ovsdb/mytrack', 'a')
        traceback.print_stack(None, None, f)
        f.close()
        return BaseCommand(self.context, 'add-br', opts, [name])

What do I miss? Thanks.