[root@liuyazhuang131 ~]# cat /proc/meminfo |grep MemTotal 
MemTotal:        2941144 kB
[root@liuyazhuang131 ~]# echo "2941144/128"|bc
22977
[root@liuyazhuang131 ~]# ulimit -u
1024
[1]+  Stopped                 vi /etc/security/limits.d/90-nproc.conf
[root@liuyazhuang131 ~]# vi /etc/security/limits.d/90-nproc.conf 
[root@liuyazhuang131 ~]# cat /etc/security/limits.d/90-nproc.conf 
# Default limit for number of user's processes to prevent
# accidental fork bombs.
# See rhbz #432903 for reasoning.
*          soft    nproc     12000
root       soft    nproc     unlimited
[root@liuyazhuang131 ~]# 
 计算方式：
default_nproc = total_memory/128K; 
$ cat /proc/meminfo |grep MemTotal
$ echo "2941144/128"|bc
$ ulimit -u
ulimit -a # 显示目前资源限制的设定 
ulimit -u # 用户最多可开启的程序数目
重启，使之生效：# reboot