There is a problem that hostcfgd blocks forever and does not react to SIGTERM causing a delay in warm boot.
When hitting this line https://github.com/Azure/sonic-buildimage/blob/master/src/sonic-host-services/scripts/hostcfgd#L1241 .

Example:

>>> from swsscommon import swsscommon
>>> c=swsscommon.ConfigDBConnector()
>>> c.subscribe('A', lambda a: None)
>>> c.connect()
>>> c.listen()


^C^C^C^C

@qiluo-msft This looks like a swss-common issue.

This wasn't seen for some reason during 500 warm boot tests on 202012 since warm reboot is executed early enough before hostcfgd stucks in a listen().

Originally posted by @stepanblyschak in sonic-net/sonic-buildimage#10510 (comment)