问题：在新建 /usr/local/php/var/run/php-fpm.pid 文件前，执行 /usr/local/php/sbin/php-fpm 启动 php-fpm，之后 service php-fpm start/stop 出现以下状况：
service php-fpm stop 出现：
Gracefully shutting down php-fpm kill: usage: kill [-s sigspec | -n signum | -sigspec] pid | jobspec ... or kill -l [sigspec]
................................... failed. Use force-quit
service php-fpm start 出现：
Starting php-fpm [24-Jul-2018 22:11:43] ERROR: unable to bind listening socket for address '127.0.0.1:9000': Address already in use (98)
[24-Jul-2018 22:11:43] ERROR: FPM initialization failed
failed
解决办法： killall php-fpm ，然后 service php-fpm start
Starting php-fpm done
service php-fpm stop
Gracefully shutting down php-fpm . done
