Nginx and uwsgi setting for heavy calculation site? - nginx

Question

I am using nginx and uwsgi(django) for site on AWS fargate.
This program doing a bit heavy calculating task.
So, I guess I should do some tuning for uwsgi or nginx.
I start uwsgi in django container with processes and threads.
uwsgi --http :8011 --processes 8 --threads 8 --module mysite.wsgi
and do nothing special for nginx
server {
listen 80;
server_name mysite;
charset utf-8;
location / {
proxy_pass http://127.0.0.1:8011/;
include /etc/nginx/uwsgi_params;
}
}
With this setting, program works, but even after heavy task finished.
Server response is still so heavy.
I checked with top command, even after task finished, not many memory are free.
top - 20:15:21 up 24 min, 0 users, load average: 4.65, 4.00, 1.91
Tasks: 15 total, 1 running, 11 sleeping, 0 stopped, 3 zombie
%Cpu(s): 0.0 us, 0.3 sy, 0.0 ni, 99.5 id, 0.2 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 3703.8 total, 176.6 free, 1095.6 used, 2431.5 buff/cache
MiB Swap: 0.0 total, 0.0 free, 0.0 used. 2382.4 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1 root 20 0 5724 284 4 S 0.0 0.0 0:00.19 bash
9 root 20 0 1398196 6260 0 S 0.0 0.2 0:00.50 amazon-ssm-agen
24 root 20 0 1410428 11772 0 S 0.0 0.3 0:00.85 ssm-agent-worke
48 root 20 0 622428 37900 1168 S 0.0 1.0 0:00.38 uwsgi
49 root 20 0 47468 1396 36 S 0.0 0.0 0:00.18 uwsgi
50 root 20 0 0 0 0 Z 0.0 0.0 0:05.75 uwsgi
56 root 20 0 1755900 424896 177332 S 0.0 11.2 0:14.92 uwsgi
59 root 20 0 1754360 365476 120228 S 0.0 9.6 0:07.77 uwsgi
60 root 20 0 0 0 0 Z 0.0 0.0 0:13.31 uwsgi
68 root 20 0 622428 36788 56 S 0.0 1.0 0:00.00 uwsgi
69 root 20 0 1755600 373404 125260 S 0.0 9.8 0:09.18 uwsgi
77 root 20 0 0 0 0 Z 0.0 0.0 0:02.90 uwsgi
129 root 20 0 1327588 10376 0 S 0.0 0.3 0:10.33 ssm-session-wor
139 root 20 0 5988 2288 1764 S 0.0 0.1 0:00.64 bash
261 root 20 0 8900 3648 3136 R 0.0 0.1 0:00.00 top
I guess this means task is not correctly freed??
However where should I check or tuning??