Django + uWSGI hold a long time to response - django

Question

I'm running a Django web application using Nginx and uWSGI. Now I meet a problem that the finish_process view in django
I have added logging at the begin and the end of Django finish_process view.
I make a request at 17:20:18, and the view finished at 17:20:48. But uWSGI does not return response at this time, and after 577 seconds, it throws IOError when it try to write response to client, because nginx close the connection (uwsgi_read_timeout is 300 seconds).
My question is why uWSGI holds the response so long after Django handled the view? I'm a bit at a loss.
Django log:
[INFO]246 views.py/finish_process 2016-03-06 17:20:18: [VIEW][START] finish_process: id=4
[INFO]282 views.py/finish_process 2016-03-06 17:20:48: [VIEW][END] finish_process: id=4
uWSGI log:
Sun Mar 6 17:29:55 2016 - uwsgi_response_writev_headers_and_body_do(): Broken pipe [core/writer.c line 296] during POST /api/finish_process/ (10.11.16.251)
IOError: write error
[pid: 3275|app: 0|req: 48689/48688] 10.11.16.251 () {34 vars in 553 bytes} [Sun Mar 6 17:20:18 2016] POST /api/finish_process/ => generated 0 bytes in 577024 msecs (HTTP/1.1 200) 3 headers in 0 bytes (0 switches on core 4)
Nginx error.log:
2016/03/06 17:25:18 [error] 3052#0: *44561 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 10.11.16.251, server: skyline, request: "POST /api/finish_process/ HTTP/1.1", upstream: "uwsgi://unix:/var/run/skyline.sock:", host: "10.11.16.253"
uwsgi.ini:
[uwsgi]
socket = /var/run/skyline.sock
chdir = /opt/skyline
processes = 1
threads = 10
master = true
env = DJANGO_SETTINGS_MODULE=skyline.prod_settings
module = skyline.wsgi:application
chmod-socket = 666
vacuum = true
die-on-term = true
Nginx conf:
server {
listen 80;
server_name skyline;
charset utf-8;
client_max_body_size 50M;
uwsgi_read_timeout 300;
location / {
include uwsgi_params;
uwsgi_pass unix:/var/run/skyline.sock;
}
}
Updated:
Solved. I made a mistake.