Your server socket listen backlog is limited to 100 connections

I run a flask app on uwsgi. I use supervisor to manage uwsgi process. I find the log saying that

your server socket listen backlog is limited to 100 connections.

How to overcome 100 connections limitation? My running script is as below:

[program:myapp]
command=uwsgi --master -s /tmp/app.sock --module myapp:app --processes 2 -H /srv/sites/mysite chmod-socket 666 --enable-threads