Help with uwsgi processes

i got my R7800 to serve my local alexa skill through uwsgi, since i already have it for luci under nginx
the skill is provided with a python script using flask, so i had to add also the uwsgi python plugin.
this all works.
my "problem" is that i can't force uwsgi to:

  • create only one process
  • kill it on idle

to save memory usage.
i tried fixing the number of threads and processes.
cheap mode.
cheaper mode.

my vassal config:

chdir = /etc/alexa/
wsgi-file =
callable = app
processes = 1
threads = 1
plugin = python, syslog
master = true
socket = /var/run/alexaSkill.socket
chmod-socket = 666
vacuum = true
die-on-term = true
die-on-idle = true

strict = true
if-not-env = UWSGI_EMPEROR_FD
cheap = true
idle = 10

cheaper-algo = spare
cheaper = 1
cheaper-initial = 1
cheaper-step = 1

the result:

10120	root	/usr/sbin/uwsgi --set die-on-idle=true --ini /etc/uwsgi/vassals/alexaSkill.ini	0%	5%	
10123	root	/usr/sbin/uwsgi --set die-on-idle=true --ini /etc/uwsgi/vassals/alexaSkill.ini	0%	5%	

where 5% each is memory usage..
what am i missing? maybe @Ansuel knows since he mantains the uwsgi package?