ps aux | grep -c php-fpm
查看php-fpm进程数：
ps aux | grep -c php-fpm
查看运行内存
/usr/bin/php -i|grep mem
重启php-fpm
/etc/init.d/php-fpm restart
pm = dynamic ; The number of child processes to be created when pm is set to 'static' and the; maximum number of child processes when pm is set to 'dynamic' or 'ondemand'.; This value sets the limit on the number of simultaneous requests that will be; served. Equivalent to the ApacheMaxClients directive with mpm_prefork.; Equivalent to the PHP_FCGI_CHILDREN environment variable in the original PHP; CGI. The below defaults are based on a server without much resources. Don't; forget to tweak pm.* to fit your needs.; Note: Used when pm is set to 'static', 'dynamic' or 'ondemand'; Note: This value is mandatory.pm.max_children = 5 ; The number of child processes created on startup.; Note: Used only when pm is set to 'dynamic'; Default Value: min_spare_servers + (max_spare_servers - min_spare_servers) / 2pm.start_servers = 2 ; The desired minimum number of idle server processes.; Note: Used only when pm is set to 'dynamic'; Note: Mandatory when pm is set to 'dynamic'pm.min_spare_servers = 1 ; The desired maximum number of idle server processes.; Note: Used only when pm is set to 'dynamic'; Note: Mandatory when pm is set to 'dynamic'pm.max_spare_servers = 3 ; The number of seconds after which an idle process will be killed.; Note: Used only when pm is set to 'ondemand'; Default Value: 10s;pm.process_idle_timeout = 10s; ; The number of requests each child process should execute before respawning.; This can be useful to work around memory leaks in 3rd party libraries. For; endless request processing specify '0'. Equivalent to PHP_FCGI_MAX_REQUESTS.; Default Value: 0;pm.max_requests = 500
解释一下：
pm = dynamic 如何控制子进程，选项有static和dynamic，默认采用dynamic；如果选择static，则由pm.max_children指定固定的子进程数。
如果选择dynamic，则由以下参数决定：
pm.max_children ，子进程最大数
pm.start_servers ，启动时的进程数
pm.min_spare_servers ，保证空闲进程数最小值，如果空闲进程小于此值，则创建新的子进程
pm.max_spare_servers ，保证空闲进程数最大值，如果空闲进程大于此值，此进行清理
对于专用服务器，pm可以设置为static。
pm.max_requests 设置每个子进程重生之前服务的请求数. 对于可能存在内存泄漏的第三方模块来说是非常有用的. 如果设置为 ’0′ 则一直接受请求. 设置为500就可以了（默认0）。
将值修改为如下：
pm.max_children = 32
pm.start_servers = 16
pm.min_spare_servers = 8
pm.max_spare_servers = 32
pm.max_requests = 500