1、ps -ylC php-fpm --sort:rss
[root@linunx-php ~]# ps -ylC php-fpm --sort:rss
S UID PID PPID C PRI NI RSS SZ WCHAN TTY TIME CMD
S 0 10966 1 0 80 0 9312 126961 ep_pol ? 00:00:32 php-fpm
S 993 14195 10966 0 80 0 30040 148996 inet_c ? 00:00:01 php-fpm
S 993 18779 10966 0 80 0 34844 148991 inet_c ? 00:00:01 php-fpm
S 993 32511 10966 0 80 0 35888 149023 inet_c ? 00:00:02 php-fpm
S 993 8091 10966 0 80 0 37224 146345 inet_c ? 00:00:02 php-fpm
S 993 22510 10966 0 80 0 38324 149119 inet_c ? 00:00:03 php-fpm
S 993 16346 10966 0 80 0 39760 149719 inet_c ? 00:00:05 php-fpm
S 993 29273 10966 0 80 0 40984 149099 inet_c ? 00:00:02 php-fpm
S 993 32181 10966 0 80 0 44600 149030 inet_c ? 00:00:02 php-fpm
S 993 21042 10966 0 80 0 45528 150063 inet_c ? 00:00:06 php-fpm
S 993 20131 10966 0 80 0 48364 149918 inet_c ? 00:00:01 php-fpm
S 993 31945 10966 0 80 0 118604 158382 inet_c ? 00:04:21 php-fpm
S 993 10988 10966 0 80 0 122688 159291 inet_c ? 00:05:40 php-fpm
S 993 24320 10966 0 80 0 140672 164756 inet_c ? 00:04:43 php-fpm
S 993 11010 10966 0 80 0 577112 277694 inet_c ? 00:05:48 php-fpm
按rss进行升序，找到内存占用的子进程号即PID