php-fpm.conf enable slowlog of php

Please do a test and create a new 20m file under the / tmp directory, and mv on linux to your uploaded PHP directory

1. check slowlog permissions
2. request_slowlog_timeout = 5 has no unit

I am on the local server and change the test interface to the interface of the online server. It is found that the waiting time after upload is very short.
and I manually turn on the PHP interface of the online server is also very fast.
therefore, the idea of "there is something wrong with PHP" is rejected.

then I looked back at the Nginx configuration and changed the IP address to 127.0.0.1.

although there is still some Waiting time, it is basically negligible.
for more solutions to this Bug, you can use the keyword Baidu [Waiting (TTFB) nginx].

the Bug that has plagued me for a day and a half has finally been solved.
finally, thank you very much, @ xialeistudio, for your reply. Although in the end, the cause of the problem was not found through php-fpm 's log.
but your answer is very helpful to me and deepens my understanding of PHP. Thank you!