首先确保php-fpm正常安装，运行命令php-fpm -t输出查看：

master进程可以理解以下信号

INT, TERM 立刻终止 
QUIT 平滑终止 
USR1 重新打开日志文件 
USR2 平滑重载所有worker进程并重新载入配置和二进制模块

确定php-fpm配置是否正确

[root@localhost php]# /usr/local/php/sbin/php-fpm -t
[04-Jun-2020 13:38:44] NOTICE: configuration file /usr/local/php/etc/php-fpm.conf test is successful

启动php-fpm

[root@localhost php]# ps -ef|grep php-fpm
root      5648  2239  0 13:39 pts/1    00:00:00 grep --color=auto php-fpm
[root@localhost php]# 
[root@localhost php]# /usr/local/php/sbin/php-fpm
[root@localhost php]# 
[root@localhost php]# ps -ef|grep php-fpm|grep -v grep
root      5650     1  0 13:39 ?        00:00:00 php-fpm: master process (/usr/local/php/etc/php-fpm.conf)
daemon    5651  5650  0 13:39 ?        00:00:00 php-fpm: pool www
daemon    5652  5650  0 13:39 ?        00:00:00 php-fpm: pool www

重启php-fpm

[root@localhost php]# ps -ef|grep php-fpm|grep -v grep                       
root      5733     1  0 13:47 ?        00:00:00 php-fpm: master process (/usr/local/php/etc/php-fpm.conf)
daemon    5734  5733  0 13:47 ?        00:00:00 php-fpm: pool www
daemon    5735  5733  0 13:47 ?        00:00:00 php-fpm: pool www
[root@localhost php]# 
[root@localhost php]# kill -SIGUSR2 $(cat /usr/local/php/var/run/php-fpm.pid)  # 重启php-fpm
[root@localhost php]# 
[root@localhost php]# ps -ef|grep php-fpm|grep -v grep                       
root      5742     1  0 13:48 ?        00:00:00 php-fpm: master process (/usr/local/php/etc/php-fpm.conf)
daemon    5743  5742  0 13:48 ?        00:00:00 php-fpm: pool www
daemon    5744  5742  0 13:48 ?        00:00:00 php-fpm: pool www

关闭php-fpm进程

[root@localhost php]# kill -INT $(cat /usr/local/php/var/run/php-fpm.pid)              
[root@localhost php]# ps -ef|grep php-fpm
root      5785  2239  0 13:51 pts/1    00:00:00 grep --color=auto php-fpm